[{"abstract":[{"text":"Dipolar (ℓ = 1) mixed modes have revealed a surprisingly weak differential rotation between the core and the envelope of evolved solar-like stars. Quadrupolar (ℓ = 2) mixed modes also contain information regarding internal dynamics but are very rarely characterised due to their low amplitude and the challenging identification of adjacent or overlapping rotationally split multiplets affected by near-degeneracy effects. We aim to extend the broadly used asymptotic seismic diagnostics beyond ℓ = 1 mixed modes by developing an analogue asymptotic description of ℓ = 2 mixed modes while explicitly accounting for near-degeneracy effects that distort their rotational multiplets. We have derived a new asymptotic formulation of near-degenerate mixed ℓ = 2 modes that describes off-diagonal terms representing the interaction between modes of adjacent radial orders. This formalism, expressed directly in the mixed-mode basis, provides analytical expressions for the near-degeneracy effects. We implemented the formalism within a global Bayesian mode-fitting framework for a direct fit of all ℓ = 0, 1, 2 modes in the power spectrum density. We were able to asymptotically model the asymmetric rotational splitting present in various radial orders of ℓ = 2 modes observed in young red giant stars without the need for any numerical stellar modelling. We applied our formalism to the Kepler target KIC 7341231, and it yielded core and envelope rotation rates consistent with previous numerical modelling while providing improved constraints from the global and model-independent approach. We also characterised the new target, KIC 8179973, measuring its rotation rate and mixed-mode parameters for the first time. As our framework relies on a direct global fit, it allows for much better precision on the asteroseismic parameters and rotation rate estimates than standard methods, yielding better constraints for rotation inversions. We have placed the first observational constraints on the asymptotic ℓ = 2 mixed-mode parameters (ΔΠ2, q2, and εg, 2), thus paving the way towards the use of asymptotic seismology beyond ℓ = 1 mixed modes.","lang":"eng"}],"author":[{"last_name":"Liagre","first_name":"Bastien Raymond Bernard","id":"662f1873-cab4-11f0-a719-8087d302868d","full_name":"Liagre, Bastien Raymond Bernard"},{"last_name":"Desai","first_name":"Aayush A","full_name":"Desai, Aayush A","id":"502cfd30-32c1-11ee-a9a4-d8dad5c6739e"},{"last_name":"Einramhof","first_name":"Lukas","id":"f1497a1a-72ef-11ef-b75a-fd877bbf6e8c","full_name":"Einramhof, Lukas"},{"orcid":"0000-0003-0142-4000","first_name":"Lisa Annabelle","full_name":"Bugnet, Lisa Annabelle","id":"d9edb345-f866-11ec-9b37-d119b5234501","last_name":"Bugnet"}],"article_number":"A321","das_tickbox":"1","corr_author":"1","OA_type":"diamond","year":"2026","month":"03","_id":"21658","status":"public","DOAJ_listed":"1","publication":"Astronomy & Astrophysics","title":"Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting","scopus_import":"1","oa":1,"article_processing_charge":"No","publisher":"EDP Sciences","doi":"10.1051/0004-6361/202558023","OA_place":"publisher","file_date_updated":"2026-04-07T09:00:50Z","ddc":["520"],"fulldoi":"https://doi.org/10.1051/0004-6361/202558023","license":"https://creativecommons.org/licenses/by/4.0/","PlanS_conform":"1","day":"01","publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"volume":707,"acknowledgement":"We thank the referee for their careful and constructive report, which has substantially enhanced both the quality and clarity of the manuscript. L. Bugnet and L. Einramhof gratefully acknowledge support from the European Research Council (ERC) under the Horizon Europe programme (Calcifer; Starting Grant agreement N°101165631). While partially funded by the European Union, views and opinions expressed are, however, those of the authors only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. The authors acknowledge the great support and feedback provided during the redaction of this article by Pr. Rafael García and Pr. Savita Mathur. We would also like to thank Dr. Emily Hatt for her insights on uncertainty estimates. The authors also thank the members of the Asteroseismology and Stellar Dynamics group of the Institute of Science and Technology Austria (ISTA) for very useful discussions: L. Barrault, S.B. Das, K. Smith. This paper includes data collected by the Kepler mission and obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the Kepler mission is provided by the NASA Science Mission Directorate. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5–26555. Software: AstroPy (Astropy Collaboration 2013, 2018), Matplotlib (Hunter 2007), NumPy (Harris et al. 2020), SciPy (Virtanen et al. 2020), emcee (Foreman-Mackey et al. 2013), celerite (Foreman-Mackey et al. 2017), slepc4py (Dalcin et al. 2011; Hernandez et al. 2005), KADACS (García et al. 2011), sloscillations (Kuszlewicz et al. 2019, 2023).","external_id":{"arxiv":["2511.05314 "]},"citation":{"chicago":"Liagre, Bastien Raymond Bernard, Aayush A Desai, Lukas Einramhof, and Lisa Annabelle Bugnet. “Near-Degeneracy Effects in Quadrupolar Mixed Modes: From an Asymptotic Description to Data Fitting.” Astronomy & Astrophysics. EDP Sciences, 2026. https://doi.org/10.1051/0004-6361/202558023.","short":"B.R.B. Liagre, A.A. Desai, L. Einramhof, L.A. Bugnet, Astronomy & Astrophysics 707 (2026).","ieee":"B. R. B. Liagre, A. A. Desai, L. Einramhof, and L. A. Bugnet, “Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting,” Astronomy & Astrophysics, vol. 707. EDP Sciences, 2026.","apa":"Liagre, B. R. B., Desai, A. A., Einramhof, L., & Bugnet, L. A. (2026). Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/202558023","mla":"Liagre, Bastien Raymond Bernard, et al. “Near-Degeneracy Effects in Quadrupolar Mixed Modes: From an Asymptotic Description to Data Fitting.” Astronomy & Astrophysics, vol. 707, A321, EDP Sciences, 2026, doi:10.1051/0004-6361/202558023.","ama":"Liagre BRB, Desai AA, Einramhof L, Bugnet LA. Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting. Astronomy & Astrophysics. 2026;707. doi:10.1051/0004-6361/202558023","ista":"Liagre BRB, Desai AA, Einramhof L, Bugnet LA. 2026. Near-degeneracy effects in quadrupolar mixed modes: From an asymptotic description to data fitting. Astronomy & Astrophysics. 707, A321."},"date_published":"2026-03-01T00:00:00Z","has_accepted_license":"1","type":"journal_article","quality_controlled":"1","intvolume":" 707","arxiv":1,"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_created":"2026-04-05T22:01:32Z","oa_version":"Published Version","language":[{"iso":"eng"}],"article_type":"original","file":[{"access_level":"open_access","date_created":"2026-04-07T09:00:50Z","creator":"dernst","file_size":12287607,"file_name":"2026_AstronomyAstrophysics_Liagre.pdf","content_type":"application/pdf","success":1,"date_updated":"2026-04-07T09:00:50Z","relation":"main_file","checksum":"560cac19dc70184626b85e71a26ee22e","file_id":"21664"}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"department":[{"_id":"LiBu"},{"_id":"IlCa"},{"_id":"GradSch"}],"publication_status":"published","date_updated":"2026-07-08T06:39:05Z"},{"issue":"5","citation":{"chicago":"Santana Santos, Carla, Nomnotho Jiyane, Thomas Quast, Maria Ibáñez, Rubén Rubio‐Presa, Pekka Peljo, and Wolfgang Schuhmann. “Evaluating Reaction Kinetics between Solid Booster and Dissolved Active Species in Redox‐mediated Flow Batteries Using Scanning Electrochemical Microscopy.” Batteries & Supercaps. Wiley, 2026. https://doi.org/10.1002/batt.70303.","mla":"Santana Santos, Carla, et al. “Evaluating Reaction Kinetics between Solid Booster and Dissolved Active Species in Redox‐mediated Flow Batteries Using Scanning Electrochemical Microscopy.” Batteries & Supercaps, vol. 9, no. 5, e70303, Wiley, 2026, doi:10.1002/batt.70303.","apa":"Santana Santos, C., Jiyane, N., Quast, T., Ibáñez, M., Rubio‐Presa, R., Peljo, P., & Schuhmann, W. (2026). Evaluating reaction kinetics between solid booster and dissolved active species in redox‐mediated flow batteries using scanning electrochemical microscopy. Batteries & Supercaps. Wiley. https://doi.org/10.1002/batt.70303","ista":"Santana Santos C, Jiyane N, Quast T, Ibáñez M, Rubio‐Presa R, Peljo P, Schuhmann W. 2026. Evaluating reaction kinetics between solid booster and dissolved active species in redox‐mediated flow batteries using scanning electrochemical microscopy. Batteries & Supercaps. 9(5), e70303.","ama":"Santana Santos C, Jiyane N, Quast T, et al. Evaluating reaction kinetics between solid booster and dissolved active species in redox‐mediated flow batteries using scanning electrochemical microscopy. Batteries & Supercaps. 2026;9(5). doi:10.1002/batt.70303","short":"C. Santana Santos, N. Jiyane, T. Quast, M. Ibáñez, R. Rubio‐Presa, P. Peljo, W. Schuhmann, Batteries & Supercaps 9 (2026).","ieee":"C. Santana Santos et al., “Evaluating reaction kinetics between solid booster and dissolved active species in redox‐mediated flow batteries using scanning electrochemical microscopy,” Batteries & Supercaps, vol. 9, no. 5. Wiley, 2026."},"acknowledgement":"The authors acknowledge funding from the European Union's Horizon Europe research and innovation programme— European Innovation Council (EIC) under the grant agreement No 101046742 (MeBattery). P.P. acknowledges the funding from the European Research Council through a Starting Grant (agreement no. 950038). Dr. Mahdi Moghaddam, University of Turku, is acknowledged for providing the CuHCF, and Prof. Hubert Girault, EPFL, is acknowledged for providing the TEMPTMA.\r\nOpen Access funding enabled and organized by Projekt DEAL.","volume":9,"date_updated":"2026-07-08T06:48:01Z","publication_status":"published","department":[{"_id":"MaIb"}],"file":[{"file_size":756344,"creator":"dernst","date_created":"2026-05-21T06:54:57Z","access_level":"open_access","file_id":"21904","checksum":"292d65503a63cc7df92b960627634dad","relation":"main_file","date_updated":"2026-05-21T06:54:57Z","success":1,"content_type":"application/pdf","file_name":"2026_BatteriesSupercaps_SantanaSantos.pdf"}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_created":"2026-05-20T14:32:37Z","oa_version":"Published Version","language":[{"iso":"eng"}],"quality_controlled":"1","intvolume":" 9","has_accepted_license":"1","type":"journal_article","date_published":"2026-05-01T00:00:00Z","OA_type":"hybrid","article_number":"e70303","das_tickbox":"1","author":[{"last_name":"Santana Santos","full_name":"Santana Santos, Carla","first_name":"Carla"},{"last_name":"Jiyane","full_name":"Jiyane, Nomnotho","first_name":"Nomnotho"},{"first_name":"Thomas","full_name":"Quast, Thomas","last_name":"Quast"},{"last_name":"Ibáñez","id":"43C61214-F248-11E8-B48F-1D18A9856A87","full_name":"Ibáñez, Maria","orcid":"0000-0001-5013-2843","first_name":"Maria"},{"full_name":"Rubio‐Presa, Rubén","first_name":"Rubén","last_name":"Rubio‐Presa"},{"last_name":"Peljo","full_name":"Peljo, Pekka","first_name":"Pekka"},{"first_name":"Wolfgang","full_name":"Schuhmann, Wolfgang","last_name":"Schuhmann"}],"abstract":[{"text":"Redox-mediated flow batteries boost energy density by utilizing dissolved redox species as charge carriers for solid charge-storage materials. This strategy strongly depends on the thermodynamics and kinetics between the solid booster and dissolved redox species. Conventional electrochemical methods often convolute intrinsic reactivity with mass transport effects, introducing complexity in determining limiting steps. We propose a strategy that confines solid boosters within recessed microelectrodes and employs scanning electrochemical microscopy (SECM) to estimate reaction kinetics between booster and dissolved active redox species. Confining the solid booster in the recessed microelectrode overcomes mass transport limitations of dissolved redox species and enables controlled polarization of the booster material, allowing deconvolution of key rate-determining factors. As an initial model system, Prussian blue-ferricyanide/ferrocyanide [Fe(CN)6]3−/4− was used as solid booster and dissolved redox active species, respectively. The methodology was further explored for copper hexacyanoferrate with N,N,N-2,2,6,6-heptamethylpiperidinyl oxy-4-ammonium chloride and nickel hydroxide with [Fe(CN)6]3−/4− and extended to Mn-based Prussian blue analogues in combination with organic redox species. Our results demonstrate that SECM coupled with the proposed recessed microelectrode strategy provides a powerful platform to disentangle interfacial kinetics and guide the rational design of solid booster-dissolved redox species and electrolytes for high-performance redox-mediated flow batteries.","lang":"eng"}],"publication_identifier":{"eissn":["2566-6223"]},"day":"01","PlanS_conform":"1","ddc":["530"],"fulldoi":"https://doi.org/10.1002/batt.70303","publisher":"Wiley","doi":"10.1002/batt.70303","file_date_updated":"2026-05-21T06:54:57Z","OA_place":"publisher","oa":1,"article_processing_charge":"Yes (via OA deal)","title":"Evaluating reaction kinetics between solid booster and dissolved active species in redox‐mediated flow batteries using scanning electrochemical microscopy","scopus_import":"1","publication":"Batteries & Supercaps","year":"2026","month":"05","_id":"21896","status":"public"},{"type":"journal_article","date_published":"2026-04-14T00:00:00Z","oa_version":"Published Version","date_created":"2026-06-29T10:47:02Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"arxiv":1,"quality_controlled":"1","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"mathsc":["05D10","05D40","05C65"],"article_type":"original","date_updated":"2026-07-08T07:24:54Z","extern":"1","publication_status":"epub_ahead","external_id":{"arxiv":["2507.05641"]},"citation":{"chicago":"He, Xiaoyu, Jiaxi Nie, Yuval Wigderson, and Hung-Hsun Yu. “Off-Diagonal Ramsey Numbers for Linear Hypergraphs.” Combinatorics, Probability and Computing. Cambridge University Press, 2026. https://doi.org/10.1017/s0963548326100443.","apa":"He, X., Nie, J., Wigderson, Y., & Yu, H.-H. (2026). Off-diagonal Ramsey numbers for linear hypergraphs. Combinatorics, Probability and Computing. Cambridge University Press. https://doi.org/10.1017/s0963548326100443","mla":"He, Xiaoyu, et al. “Off-Diagonal Ramsey Numbers for Linear Hypergraphs.” Combinatorics, Probability and Computing, Cambridge University Press, 2026, pp. 1–14, doi:10.1017/s0963548326100443.","ama":"He X, Nie J, Wigderson Y, Yu H-H. Off-diagonal Ramsey numbers for linear hypergraphs. Combinatorics, Probability and Computing. 2026:1-14. doi:10.1017/s0963548326100443","ista":"He X, Nie J, Wigderson Y, Yu H-H. 2026. Off-diagonal Ramsey numbers for linear hypergraphs. Combinatorics, Probability and Computing., 1–14.","short":"X. He, J. Nie, Y. Wigderson, H.-H. Yu, Combinatorics, Probability and Computing (2026) 1–14.","ieee":"X. He, J. Nie, Y. Wigderson, and H.-H. Yu, “Off-diagonal Ramsey numbers for linear hypergraphs,” Combinatorics, Probability and Computing. Cambridge University Press, pp. 1–14, 2026."},"page":"1-14","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1017/S0963548326100443"}],"publication":"Combinatorics, Probability and Computing","year":"2026","status":"public","_id":"22152","month":"04","oa":1,"article_processing_charge":"No","title":"Off-diagonal Ramsey numbers for linear hypergraphs","scopus_import":"1","ddc":["500"],"fulldoi":"https://doi.org/10.1017/s0963548326100443","publisher":"Cambridge University Press","OA_place":"publisher","doi":"10.1017/s0963548326100443","publication_identifier":{"issn":["0963-5483"],"eissn":["1469-2163"]},"day":"14","abstract":[{"lang":"eng","text":"We study off-diagonal Ramsey numbers 𝑟(𝐻,𝐾(𝑘)\r\n𝑛) of 𝑘-uniform hypergraphs, where 𝐻 is a fixed linear 𝑘-uniform hypergraph and 𝐾(𝑘)\r\n𝑛 is complete on 𝑛 vertices. Recently, Conlon, Fox, Gunby, He, Mubayi, Suk, and Verstraëte disproved the folklore conjecture that 𝑟(𝐻,𝐾(3)\r\n𝑛) always grows polynomially in 𝑛. In this paper, we show that much larger growth rates are possible in higher uniformity. In uniformity 𝑘 ≥4, we prove that for any constant 𝐶 >0, there exists a linear 𝑘-uniform hypergraph 𝐻 for which\r\n\r\n𝑟(𝐻,𝐾(𝑘)\r\n𝑛)≥twr𝑘−2(2(log𝑛)𝐶)."}],"author":[{"full_name":"He, Xiaoyu","first_name":"Xiaoyu","last_name":"He"},{"last_name":"Nie","first_name":"Jiaxi","full_name":"Nie, Jiaxi"},{"first_name":"Yuval","id":"2d0023a0-1567-11f0-833d-d5c1e476d4b5","full_name":"Wigderson, Yuval","last_name":"Wigderson"},{"first_name":"Hung-Hsun","full_name":"Yu, Hung-Hsun","last_name":"Yu"}],"OA_type":"hybrid"},{"oa":1,"article_processing_charge":"Yes (via OA deal)","title":"Single-nucleus resolution of sex-biased expression and dosage compensation in Drosophila melanogaster","scopus_import":"1","publication":"Proceedings of the Royal Society B Biological Sciences","year":"2026","_id":"21161","status":"public","month":"01","publication_identifier":{"eissn":["1471-2954"]},"day":"28","PlanS_conform":"1","fulldoi":"https://doi.org/10.1098/rspb.2025.2471","ddc":["570"],"publisher":"Royal Society of London","file_date_updated":"2026-02-16T09:26:02Z","OA_place":"publisher","doi":"10.1098/rspb.2025.2471","pmid":1,"author":[{"first_name":"Carolina","orcid":"0000-0003-1945-2245","full_name":"De Castro Barbosa Rodrigues Barata, Carolina","id":"20565186-803f-11ed-ab7e-96a4ff7694ef","last_name":"De Castro Barbosa Rodrigues Barata"},{"orcid":"0000-0002-4579-8306","first_name":"Beatriz","full_name":"Vicoso, Beatriz","id":"49E1C5C6-F248-11E8-B48F-1D18A9856A87","last_name":"Vicoso"}],"abstract":[{"text":"In many species, sex-biased expression is widespread and thought to contribute to sexual dimorphism. While bulk RNA-sequencing has been instrumental in identifying strongly sex-biased genes, it lacks resolution to assess variation across cell-types and tissue compartments. Using single-nucleus expression data from the Fly Cell Atlas, we investigate sex differences in adult Drosophila melanogaster. We find that differences in cell-type composition between the sexes are not a major source of sex-bias, as for the vast majority of genes, the degree of sex-bias is similar regardless of whether sex differences in cell-type composition are controlled for or not. Our analysis confirms a deficit of X-linked male-biased genes in the body’s somatic tissues that is widespread across cell-types. We also find the excess of X-linked female-biased genes to be associated with nervous system cells in the head but with epithelial cells in the body’s somatic tissues, showing that single-nucleus data crucially resolves sex-bias at the cell-type level. We investigate dosage compensation (DC) across 15 tissues and 17 cell-types. We observe that it varies throughout the body. Surprisingly, we observe a lack of DC in a cluster of main cells within the male accessory glands. This result highlights the importance of understanding context-dependent DC.","lang":"eng"}],"OA_type":"hybrid","acknowledged_ssus":[{"_id":"ScienComp"},{"_id":"Bio"}],"article_number":"20252471","das_tickbox":"1","corr_author":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","date_created":"2026-02-08T23:02:49Z","language":[{"iso":"eng"}],"intvolume":" 293","quality_controlled":"1","has_accepted_license":"1","type":"journal_article","date_published":"2026-01-28T00:00:00Z","date_updated":"2026-07-08T09:17:41Z","publication_status":"published","department":[{"_id":"BeVi"}],"file":[{"date_updated":"2026-02-16T09:26:02Z","checksum":"d76afebca0a6f112df0146ae2d929f36","relation":"main_file","file_id":"21226","file_name":"2026_RoyalSocPubProceedingsB_Barata.pdf","content_type":"application/pdf","success":1,"date_created":"2026-02-16T09:26:02Z","creator":"dernst","file_size":2230841,"access_level":"open_access"}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","volume":293,"acknowledgement":"This work was partly funded by an Austrian Science Foundation FWF ESPRIT fellowship (10.55776/ESP6331524) to C.B. We would like to thank the Vicoso group for their invaluable input and discussions throughout this work. We thank Filip Ruzicka for his insightful comments on the manuscript. All computational resources were provided by the Scientific Computing Unit at ISTA. This research was also supported through resources provided by the Imaging & Optics Facility (IOF) at ISTA.","project":[{"_id":"90ef7108-16d5-11f0-9cad-e6e116913473","name":"Does genetic drift set a limit on the adaptive evolution of sex-biased expression?","grant_number":"ESP 6331524"}],"issue":"2063","external_id":{"pmid":["41592777"]},"citation":{"ieee":"C. de Castro Barbosa Rodrigues Barata and B. Vicoso, “Single-nucleus resolution of sex-biased expression and dosage compensation in Drosophila melanogaster,” Proceedings of the Royal Society B Biological Sciences, vol. 293, no. 2063. Royal Society of London, 2026.","short":"C. de Castro Barbosa Rodrigues Barata, B. Vicoso, Proceedings of the Royal Society B Biological Sciences 293 (2026).","ista":"de Castro Barbosa Rodrigues Barata C, Vicoso B. 2026. Single-nucleus resolution of sex-biased expression and dosage compensation in Drosophila melanogaster. Proceedings of the Royal Society B Biological Sciences. 293(2063), 20252471.","ama":"de Castro Barbosa Rodrigues Barata C, Vicoso B. Single-nucleus resolution of sex-biased expression and dosage compensation in Drosophila melanogaster. Proceedings of the Royal Society B Biological Sciences. 2026;293(2063). doi:10.1098/rspb.2025.2471","mla":"de Castro Barbosa Rodrigues Barata, Carolina, and Beatriz Vicoso. “Single-Nucleus Resolution of Sex-Biased Expression and Dosage Compensation in Drosophila Melanogaster.” Proceedings of the Royal Society B Biological Sciences, vol. 293, no. 2063, 20252471, Royal Society of London, 2026, doi:10.1098/rspb.2025.2471.","apa":"de Castro Barbosa Rodrigues Barata, C., & Vicoso, B. (2026). Single-nucleus resolution of sex-biased expression and dosage compensation in Drosophila melanogaster. Proceedings of the Royal Society B Biological Sciences. Royal Society of London. https://doi.org/10.1098/rspb.2025.2471","chicago":"Castro Barbosa Rodrigues Barata, Carolina de, and Beatriz Vicoso. “Single-Nucleus Resolution of Sex-Biased Expression and Dosage Compensation in Drosophila Melanogaster.” Proceedings of the Royal Society B Biological Sciences. Royal Society of London, 2026. https://doi.org/10.1098/rspb.2025.2471."}},{"OA_type":"gold","keyword":["Actinokineospora","Antarctica","antimicrobial discovery","biosynthetic gene cluster","genome mining","microbial competition","nonribosomalpeptide synthetase","siderophores"],"das_tickbox":"1","corr_author":"1","article_number":"e70386","abstract":[{"text":"The global rise of antimicrobial resistance has intensified the search for new microbial metabolites from underexplored environments and taxonomic groups. Extreme and geographically isolated habitats such as Antarctic terrestrial ecosystems represent promising reservoirs of biosynthetic diversity, particularly among rare and difficult-to-cultivate actinomycetes that may produce chemically diverse metabolites with potential biotechnological applications. Here, we report the characterization of kineochelins, a previously undescribed group of siderophores produced by the Antarctic isolate Actinokineospora sp. UV203, representing a difficult-to-cultivate actinomycete lineage. Structural elucidation revealed a set of closely related congeners with a mixed-ligand architecture consistent with metal-chelating activity. Genome mining combined with transcriptomic analysis identified a dedicated nonribosomal peptide synthetase-encoding biosynthetic gene cluster responsible for kineochelin production. Comparative genomic analyses indicated that, although kineochelin biosynthetic genes share limited similarity with known mixed-ligand siderophores, their gene content and organization differ substantially, suggesting a distinct biosynthetic lineage. Functional characterization of the culture supernatant and an enriched pre-purified kineochelin fraction demonstrated strong and selective iron chelation, with high affinity for ferric and ferrous iron. Crude culture extracts inhibited the growth of bacterial strains isolated from the same Antarctic environment, indicating that kineochelins may contribute to iron-mediated microbial competition. In addition, kineochelin-enriched pre-purified fractions showed moderate selective inhibitory activity against the opportunistic yeast pathogen Nakaseomyces glabratus and a clinical isolate of Saccharomyces cerevisiae associated with invasive infection. These findings expand the chemical and biosynthetic diversity known within the genus Actinokineospora and demonstrate that Antarctic rare actinomycetes represent valuable sources of previously unexplored natural products. The discovery of kineochelins highlights the potential of genome-guided exploration of polar microorganisms for identifying bioactive metabolites with relevance for antimicrobial discovery and biotechnology.","lang":"eng"}],"pmid":1,"author":[{"last_name":"Kralova","first_name":"Stanislava","full_name":"Kralova, Stanislava"},{"first_name":"Peter","full_name":"Spacek, Peter","last_name":"Spacek"},{"full_name":"Gafriller, Johannes","first_name":"Johannes","last_name":"Gafriller"},{"last_name":"Bezdicek","full_name":"Bezdicek, Matej","first_name":"Matej"},{"last_name":"Medvedcova","full_name":"Medvedcova, Viktoria","first_name":"Viktoria"},{"first_name":"Joana","full_name":"Séneca, Joana","last_name":"Séneca"},{"full_name":"Osvatic, Jay","first_name":"Jay","last_name":"Osvatic"},{"last_name":"Grienke","first_name":"Ulrike","full_name":"Grienke, Ulrike"},{"last_name":"Rattei","first_name":"Thomas","full_name":"Rattei, Thomas"},{"first_name":"Olga N.","full_name":"Sekurova, Olga N.","last_name":"Sekurova"},{"last_name":"Zotchev","first_name":"Sergey B.","full_name":"Zotchev, Sergey B."},{"last_name":"Zehl","first_name":"Martin","orcid":"0000-0001-9685-0373","full_name":"Zehl, Martin","id":"8e016d5b-5d77-11f0-86d2-96cdb3922a55"},{"first_name":"Alexander","full_name":"Loy, Alexander","last_name":"Loy"}],"ddc":["570"],"fulldoi":"https://doi.org/10.1111/1751-7915.70386","file_date_updated":"2026-07-13T06:57:19Z","OA_place":"publisher","doi":"10.1111/1751-7915.70386","publisher":"Wiley","publication_identifier":{"eissn":["1751-7915"]},"day":"01","publication":"Microbial Biotechnology","DOAJ_listed":"1","_id":"22254","month":"06","status":"public","year":"2026","article_processing_charge":"Yes","oa":1,"scopus_import":"1","title":"Kineochelins - A new group of siderophores from an antarctic bacterium","citation":{"chicago":"Kralova, Stanislava, Peter Spacek, Johannes Gafriller, Matej Bezdicek, Viktoria Medvedcova, Joana Séneca, Jay Osvatic, et al. “Kineochelins - A New Group of Siderophores from an Antarctic Bacterium.” Microbial Biotechnology. Wiley, 2026. https://doi.org/10.1111/1751-7915.70386.","ista":"Kralova S, Spacek P, Gafriller J, Bezdicek M, Medvedcova V, Séneca J, Osvatic J, Grienke U, Rattei T, Sekurova ON, Zotchev SB, Zehl M, Loy A. 2026. Kineochelins - A new group of siderophores from an antarctic bacterium. Microbial Biotechnology. 19(6), e70386.","ama":"Kralova S, Spacek P, Gafriller J, et al. Kineochelins - A new group of siderophores from an antarctic bacterium. Microbial Biotechnology. 2026;19(6). doi:10.1111/1751-7915.70386","mla":"Kralova, Stanislava, et al. “Kineochelins - A New Group of Siderophores from an Antarctic Bacterium.” Microbial Biotechnology, vol. 19, no. 6, e70386, Wiley, 2026, doi:10.1111/1751-7915.70386.","apa":"Kralova, S., Spacek, P., Gafriller, J., Bezdicek, M., Medvedcova, V., Séneca, J., … Loy, A. (2026). Kineochelins - A new group of siderophores from an antarctic bacterium. Microbial Biotechnology. Wiley. https://doi.org/10.1111/1751-7915.70386","ieee":"S. Kralova et al., “Kineochelins - A new group of siderophores from an antarctic bacterium,” Microbial Biotechnology, vol. 19, no. 6. Wiley, 2026.","short":"S. Kralova, P. Spacek, J. Gafriller, M. Bezdicek, V. Medvedcova, J. Séneca, J. Osvatic, U. Grienke, T. Rattei, O.N. Sekurova, S.B. Zotchev, M. Zehl, A. Loy, Microbial Biotechnology 19 (2026)."},"external_id":{"pmid":["42210522"],"biorxivid":["10.64898/2026.02.23.707395"]},"issue":"6","biorxivid":1,"acknowledgement":"This work was supported by the Czech Antarctic Research Programme 2025–2027 (VAN 2025) and the University of Vienna via the Research Platform Secondary Metabolomes of Bacterial Communities (MetaBac). S.K. has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 101020356 (DEFCOMANT, https://doi.org/10.3030/101020356) and MASH StG/CoG (MUNI/SC/1946/2024) by Masaryk University. T.R. and A.L. were funded in part by the Austrian Science Fund FWF [grant DOI https://doi.org/10.55776/COE7]. M.B. was funded by the Ministry of Health, Czech Republic—conceptual development of research organization (FNBr, 65269705). The Life Science Compute Cluster LiSC at the University of Vienna provided the high-performance computing infrastructure for this study. We thank Julia Ramesmayer and Sara Malinowski (Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna) for assistance during high molecular weight extraction and RNA extraction. The authors thank Anna Fabisikova and Michael Klemm-Abraham from the Mass Spectrometry Centre and the team of the NMR Centre (both core facilities of the Faculty of Chemistry, University of Vienna, and members of the Vienna Life Science Instruments) for assistance with data acquisition. We are thankful to Dr. Jaime Felipe Guerrero Garzón for helpful discussions on the use of a rrn operon promoter strategy. For open access purposes, the authors have applied for a CC BY public copyright licence to any author-accepted manuscript version arising from this submission. Dr. Martin Kello (Department of Pharmacology, Faculty of Medicine, Pavol Jozef Šafárik University, Košice, Slovakia) and Dr. Michal Goga (Department of Plant Biology, Faculty of Science and Center for Interdisciplinary Biosciences, Technology and Innovation Park, Pavol Jozef Šafárik University in Košice, Košice, Slovakia), funded by VEGA 1/0498/23, are acknowledged for their assistance with the antiproliferative assays. This work was supported by Horizon 2020 Framework Programme, 101020356; Universität Wien, MetaBac; Ministry of Education, Youth and Sports, VAN 2025; Masarykova Univerzita, MUNI/SC/1946/2024; Austrian Science Fund, 10.55776/COE7; Ministerstvo Zdravotnictví České Republiky, FNBr, 65269705; Vedecká grantová agentúra Ministerstva školstva, výskumu, vývoja a mládeže Slovenskej republiky a Slovenskej akadémie vied, VEGA 1/0498/23.","volume":19,"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"file":[{"access_level":"open_access","file_size":2497486,"creator":"dernst","date_created":"2026-07-13T06:57:19Z","success":1,"content_type":"application/pdf","file_name":"2026_MicrobialBiotechnology_Kralova.pdf","file_id":"22271","checksum":"4f735714644f1049b22b014225843d8d","relation":"main_file","date_updated":"2026-07-13T06:57:19Z"}],"article_type":"original","supplementarymaterial":"yes","date_updated":"2026-07-13T06:59:08Z","department":[{"_id":"MassSpec"}],"publication_status":"published","type":"journal_article","dataavailabilitystatement":"The genome sequence and transcriptomic data of strain Actinokineospora sp. UV203 are available on NCBI (BioProject accession number PRJNA1331526). The nearly full-length 16S rRNA gene (1395 bp) of strain Actinokineospora sp. UV203 is available on NCBI (accession number PX090945). The NMR data of kineochelin E1 and A1 are deposited in the Natural Products Magnetic Resonance Database (NP-MRD) under accession numbers NP0352113 and NP0352114, respectively.","has_accepted_license":"1","date_published":"2026-06-01T00:00:00Z","language":[{"iso":"eng"}],"oa_version":"Published Version","date_created":"2026-07-08T09:19:43Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","quality_controlled":"1","intvolume":" 19"},{"ddc":["520"],"fulldoi":"https://doi.org/10.3847/2041-8213/ae7bfd","publisher":"IOP Publishing","OA_place":"publisher","doi":"10.3847/2041-8213/ae7bfd","file_date_updated":"2026-07-13T07:46:22Z","publication_identifier":{"issn":["2041-8205"],"eissn":["2041-8213"]},"day":"10","publication":"The Astrophysical Journal Letters","DOAJ_listed":"1","year":"2026","status":"public","_id":"22263","month":"07","oa":1,"article_processing_charge":"Yes","title":"A black hole star at cosmic noon: Extreme Balmer break, photospheric continuum, and broad absorption by thick winds in a Little Red Dot at z = 1.7","scopus_import":"1","OA_type":"gold","article_number":"L37","corr_author":"1","das_tickbox":"1","abstract":[{"text":"Recent studies at high redshift have revealed an enigmatic class of little red dots (LRDs) with extreme Balmer breaks, stronger than in any stellar atmosphere. However, it is unclear whether such objects exist at lower redshift, especially given the low number of LRDs reported at z ≲ 2. Here, we report the discovery of PAN-BH*-1, an LRD with an extreme Balmer break at z = 1.73, identified from JWST/NIRCam pure-parallel imaging taken by the PANORAMIC survey, and confirmed by deep VLT/X-Shooter spectroscopy. The rest-optical to near-infrared spectral energy distribution of PAN-BH*-1 is consistent with a photospheric continuum with effective temperature Teff ≈ 4800 K. The broad Hα emission line shows remarkably deep absorption, stronger than previously measured in any LRD. The absorption trough spans from −520 to +267 km s−1 with respect to the systemic redshift. The presence of blue- and red-shifted absorption suggests complex dynamics of the obscuring gas along the line of sight. We speculate that the absorption trough can be produced by a thick wind launched from a thick, rotating photospheric disk, the latter being the source of the red optical continuum. While the source is unresolved in the rest-optical JWST data (reff < 47 pc), the rest-near-UV Hubble Space Telescope imaging shows an extended morphology with (formular displayed) kpc, which we interpret as a host galaxy with a stellar mass of ∼10^8 M⊙, in line with the narrow Hα emission. The discovery of this object at cosmic noon highlights the feasibility of systematic searches for extreme LRDs with wide-area facilities such as Euclid and Roman.","lang":"eng"}],"author":[{"full_name":"Torralba Torregrosa, Alberto","id":"018f0249-0e87-11f0-b167-cbce08fbd541","orcid":"0000-0001-5586-6950","first_name":"Alberto","last_name":"Torralba Torregrosa"},{"last_name":"Matthee","id":"7439a258-f3c0-11ec-9501-9df22fe06720","full_name":"Matthee, Jorryt J","first_name":"Jorryt J","orcid":"0000-0003-2871-127X"},{"full_name":"Weibel, Andrea","first_name":"Andrea","last_name":"Weibel"},{"first_name":"Rohan P.","full_name":"Naidu, Rohan P.","last_name":"Naidu"},{"last_name":"Ma","full_name":"Ma, Yilun","first_name":"Yilun"},{"full_name":"Cloonan, Aidan P.","first_name":"Aidan P.","last_name":"Cloonan"},{"last_name":"Desai","full_name":"Desai, Aayush A","id":"502cfd30-32c1-11ee-a9a4-d8dad5c6739e","first_name":"Aayush A"},{"first_name":"Anna","full_name":"De Graaff, Anna","last_name":"De Graaff"},{"first_name":"Jenny E.","full_name":"Greene, Jenny E.","last_name":"Greene"},{"first_name":"Christian Kragh","full_name":"Jespersen, Christian Kragh","last_name":"Jespersen"},{"orcid":"0000-0001-5346-6048","first_name":"Ivan","full_name":"Kramarenko, Ivan","id":"9a9394cb-3200-11ee-973b-f5ba2a8b16e4","last_name":"Kramarenko"},{"last_name":"Mascia","id":"edaf889c-c7cd-11ef-ab1b-bb28c431bd29","full_name":"Mascia, Sara","first_name":"Sara"},{"first_name":"Pascal A.","full_name":"Oesch, Pascal A.","last_name":"Oesch"},{"first_name":"Wendy Q.","full_name":"Sun, Wendy Q.","last_name":"Sun"},{"full_name":"Williams, Christina C.","first_name":"Christina C.","last_name":"Williams"}],"file":[{"date_created":"2026-07-13T07:46:22Z","file_size":5419071,"creator":"dernst","access_level":"open_access","date_updated":"2026-07-13T07:46:22Z","file_id":"22274","relation":"main_file","checksum":"7600db260d799ddea45cf3bd01effe41","content_type":"application/pdf","file_name":"2026_AstrophysicalJourLetters_Torralba.pdf","success":1}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","date_updated":"2026-07-13T08:08:41Z","supplementarymaterial":"yes","publication_status":"published","department":[{"_id":"JoMa"},{"_id":"IlCa"},{"_id":"GradSch"}],"has_accepted_license":"1","dataavailabilitystatement":"Based on observations made with ESO Telescopes at the Paranal Observatory under program IDs 116.294D and 116.2AQ0.\r\n\r\nThis work is based in part on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with programs #2514 and #9433. C.C.W. gratefully acknowledges support for program JWST-GO-2514 provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127. The authors acknowledge the team led by co-PIs R. Maiolino and F. D’Eugenio for developing their observing program with a zero-exclusive-access period.\r\n\r\nThis research is based on observations made with the NASA/ESA Hubble Space Telescope obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5–26555. These observations are associated with program #15117.\r\n\r\nThe JWST and HST data presented in this article were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The specific observations analyzed can be accessed via doi:10.17909/ydwx-st06.\r\n\r\nThis work is based in part on observations made with the Spitzer Space Telescope, which was operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. The Spitzer data used in this work can be found in doi:10.26131/IRSA3.\r\n\r\nThis work was supported by the International Space Science Institute (ISSI) in Bern, through ISSI International Team project #25-659 “Little Red Dots, Big Open Questions.”\r\n\r\nJWST cartoon in Figure 6, credit: NASA.\r\n\r\nFacilities: VLT:Kueyen - Very Large Telescope (Kueyen) (X-Shooter), VLT:Yepun (HAWK-I), JWST - James Webb Space Telescope (NIRCam, NIRspec), HST - Hubble Space Telescope satellite (ACS), Spitzer - Spitzer Space Telescope satellite (IRAC, MIPS) - .\r\n\r\nSoftware: astropy (Astropy Collaboration et al. 2013, 2018; Astropy Collaboration et al. 2022), NumPy (C. R. Harris et al. 2020), SciPy (P. Virtanen et al. 2020), pysersic (I. Pasha & T. B. Miller 2023), stpsf (M. D. Perrin et al. 2014), lmfit (M. Newville et al. 2014), EsoRex (ESO CPL Development Team 2015), Claude (used for Python coding; https://claude.ai/), SEP (K. Barbary 2016).","type":"journal_article","researchdata_availability":"yes","date_published":"2026-07-10T00:00:00Z","date_created":"2026-07-12T22:02:17Z","oa_version":"Published Version","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"quality_controlled":"1","arxiv":1,"intvolume":" 1005","external_id":{"arxiv":["2603.28335"]},"citation":{"chicago":"Torralba Torregrosa, Alberto, Jorryt J Matthee, Andrea Weibel, Rohan P. Naidu, Yilun Ma, Aidan P. Cloonan, Aayush A Desai, et al. “A Black Hole Star at Cosmic Noon: Extreme Balmer Break, Photospheric Continuum, and Broad Absorption by Thick Winds in a Little Red Dot at z = 1.7.” The Astrophysical Journal Letters. IOP Publishing, 2026. https://doi.org/10.3847/2041-8213/ae7bfd.","short":"A. Torralba Torregrosa, J.J. Matthee, A. Weibel, R.P. Naidu, Y. Ma, A.P. Cloonan, A.A. Desai, A. De Graaff, J.E. Greene, C.K. Jespersen, I. Kramarenko, S. Mascia, P.A. Oesch, W.Q. Sun, C.C. Williams, The Astrophysical Journal Letters 1005 (2026).","ieee":"A. Torralba Torregrosa et al., “A black hole star at cosmic noon: Extreme Balmer break, photospheric continuum, and broad absorption by thick winds in a Little Red Dot at z = 1.7,” The Astrophysical Journal Letters, vol. 1005, no. 2. IOP Publishing, 2026.","mla":"Torralba Torregrosa, Alberto, et al. “A Black Hole Star at Cosmic Noon: Extreme Balmer Break, Photospheric Continuum, and Broad Absorption by Thick Winds in a Little Red Dot at z = 1.7.” The Astrophysical Journal Letters, vol. 1005, no. 2, L37, IOP Publishing, 2026, doi:10.3847/2041-8213/ae7bfd.","apa":"Torralba Torregrosa, A., Matthee, J. J., Weibel, A., Naidu, R. P., Ma, Y., Cloonan, A. P., … Williams, C. C. (2026). A black hole star at cosmic noon: Extreme Balmer break, photospheric continuum, and broad absorption by thick winds in a Little Red Dot at z = 1.7. The Astrophysical Journal Letters. IOP Publishing. https://doi.org/10.3847/2041-8213/ae7bfd","ista":"Torralba Torregrosa A, Matthee JJ, Weibel A, Naidu RP, Ma Y, Cloonan AP, Desai AA, De Graaff A, Greene JE, Jespersen CK, Kramarenko I, Mascia S, Oesch PA, Sun WQ, Williams CC. 2026. A black hole star at cosmic noon: Extreme Balmer break, photospheric continuum, and broad absorption by thick winds in a Little Red Dot at z = 1.7. The Astrophysical Journal Letters. 1005(2), L37.","ama":"Torralba Torregrosa A, Matthee JJ, Weibel A, et al. A black hole star at cosmic noon: Extreme Balmer break, photospheric continuum, and broad absorption by thick winds in a Little Red Dot at z = 1.7. The Astrophysical Journal Letters. 2026;1005(2). doi:10.3847/2041-8213/ae7bfd"},"issue":"2","acknowledgement":"IOP Science home\r\nThe Astrophysical Journal Letters\r\nThe American Astronomical Society, find out more.\r\n\r\nThe following article isOpen access\r\nA Black Hole Star at Cosmic Noon: Extreme Balmer Break, Photospheric Continuum, and Broad Absorption by Thick Winds in a Little Red Dot at z = 1.7\r\nAlberto Torralba, Jorryt Matthee, Andrea Weibel, Rohan P. Naidu, Yilun Ma, Aidan P. Cloonan, Aayush Desai, Anna de Graaff, Jenny E. Greene, Christian Kragh JespersenShow full author list\r\n\r\nPublished 2026 June 30 • © 2026. The Author(s). Published by the American Astronomical Society.\r\nThe Astrophysical Journal Letters, Volume 1005, Number 2\r\nCitation Alberto Torralba et al 2026 ApJL 1005 L37\r\nDOI 10.3847/2041-8213/ae7bfd\r\n\r\nPDFOpens in a new tab.ePub\r\nAuthors\r\nFigures\r\nTables\r\nReferences\r\nArticle data\r\nPDFOpens in a new tab.ePub\r\nArticle metrics\r\n122 Total downloads\r\n\r\nShare this article\r\nArticle information\r\nAbstract\r\nRecent studies at high redshift have revealed an enigmatic class of little red dots (LRDs) with extreme Balmer breaks, stronger than in any stellar atmosphere. However, it is unclear whether such objects exist at lower redshift, especially given the low number of LRDs reported at z ≲ 2. Here, we report the discovery of PAN-BH*-1, an LRD with an extreme Balmer break at z = 1.73, identified from JWST/NIRCam pure-parallel imaging taken by the PANORAMIC survey, and confirmed by deep VLT/X-Shooter spectroscopy. The rest-optical to near-infrared spectral energy distribution of PAN-BH*-1 is consistent with a photospheric continuum with effective temperature Teff ≈ 4800 K. The broad Hα emission line shows remarkably deep absorption, stronger than previously measured in any LRD. The absorption trough spans from −520 to +267 km s−1 with respect to the systemic redshift. The presence of blue- and red-shifted absorption suggests complex dynamics of the obscuring gas along the line of sight. We speculate that the absorption trough can be produced by a thick wind launched from a thick, rotating photospheric disk, the latter being the source of the red optical continuum. While the source is unresolved in the rest-optical JWST data (reff < 47 pc), the rest-near-UV Hubble Space Telescope imaging shows an extended morphology with \r\n kpc, which we interpret as a host galaxy with a stellar mass of ∼108 M⊙, in line with the narrow Hα emission. The discovery of this object at cosmic noon highlights the feasibility of systematic searches for extreme LRDs with wide-area facilities such as Euclid and Roman.\r\n\r\nExport citation and abstract\r\nBibTeXRIS\r\n\r\nPrevious article in issue\r\nNext article in issue\r\n\r\nOriginal content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.\r\n\r\n1. Introduction\r\nThe unprecedented sensitivity of JWST has enabled the discovery of a new, abundant population of objects at redshifts z ≈ 3–9 nicknamed the “little red dots” (LRDs). These are characterized by their compact rest-frame optical morphology, broad emission lines, and a characteristic rest-UV to optical “V-shape” in their spectral energy distributions (SED; e.g., D. D. Kocevski et al. 2023; V. Kokorev et al. 2024; J. Matthee et al. 2024; I. Labbe et al. 2025).\r\n\r\nThe nature of LRDs is highly debated (see K. Inayoshi & L. C. Ho 2025, for a recent overview) as the LRDs show systematic differences with respect to other types of active galactic nuclei (AGN), such as faintness in X-rays (e.g., T. T. Ananna et al. 2024; M. Yue et al. 2024), mid-to-far-infrared dust emission (e.g., G. C. K. Leung et al. 2025; C. C. Williams et al. 2024; I. Delvecchio et al. 2025; D. J. Setton et al. 2025; M. Xiao et al. 2025), and radio (e.g., G. Mazzolari et al. 2026; M. A. Latif et al. 2025; K. Perger et al. 2025, see A. J. Gloudemans et al. 2025).\r\n\r\nA recurring spectral feature of LRDs is the presence of a strong Balmer break (e.g., D. J. Setton et al. 2025; B. Wang et al. 2024; R. E. Hviding et al. 2025; W. Q. Sun et al. 2026), in some cases stronger than any star or stellar population can produce. The two most prominent examples known to date are The Cliff at z ≈ 3.5 (A. de Graaff et al. 2025a) and MoM-BH* at z ≈ 7.8 (R. P. Naidu et al. 2025). The joint appearance of strong Balmer lines as well as strong Balmer breaks has been modeled as being due to absorption by a dense, neutral gas with a high column density in the line of sight to a highly ionizing source (K. Inayoshi & R. Maiolino 2025; X. Ji et al. 2025; A. Sneppen et al. 2026; A. Torralba et al. 2026). These observations have sparked the development of new theoretical models, ranging from a spherical envelope analogous to stellar atmospheres (e.g., M. C. Begelman & J. Dexter 2026; D. Kido et al. 2025; H. Liu et al. 2025; D. Nandal & A. Loeb 2026) or a thick accretion disk (e.g., H. Liu et al. 2025, 2026; K. Inayoshi et al. 2025; Y.-X. Chen et al. 2026).\r\n\r\nBesides their spectral features, the evolution of the LRD number densities is also in stark contrast to other types of AGNs (e.g., K. Inayoshi 2025). At 4 ≲ z ≲ 7, LRDs represent a few percent of the galaxy population (e.g., D. D. Kocevski et al. 2023, 2025; J. E. Greene et al. 2024; V. Kokorev et al. 2024; X. Lin et al. 2024; R. Maiolino et al. 2024; J. Matthee et al. 2024), with number densities of ≳10−5 Mpc−3. The number density does not appear to drop quickly beyond z > 5 (e.g., J. Zhang et al. 2026), with various LRDs having been confirmed at z > 8 (V. Kokorev et al. 2023; A. J. Taylor et al. 2025; R. Tripodi et al. 2025), well beyond the quasar redshift record (F. Wang et al. 2021). Photometric LRD candidates exist beyond z > 10 (T. S. Tanaka et al. 2025). In turn, the number density of LRDs seems to decline steeply at z < 4 (e.g., Y. Ma et al. 2026), with estimates of a number density of ∼10−6 cMpc−3 at z ∼ 2 and even ∼10−10 cMpc−3 at z ≈ 0.3 (X. Lin et al. 2026). While it is challenging to ensure a uniform selection function across such a large redshift baseline and dedicated spectroscopic follow-up of such lower redshift candidates has only just started, it is challenging to attribute five orders of magnitude to such effects.\r\n\r\nMotivated by the discovery of rare objects with extreme Balmer breaks at z > 3 and the very small number of known LRDs at lower redshift, we performed a dedicated search for extreme Balmer break objects using a template-match approach on a large compilation of JWST NIRCam data over ≈0.3 deg2 and z ≈ 1.5–7.0. This survey is presented in A. Weibel et al. (2026a). As part of an ongoing ground-based spectroscopic campaign of LRD candidates at z ∼ 2 (Y. Ma et al. 2026), we followed up the most luminous candidate with a photometric redshift of z ≈ 2 with the X-Shooter spectrograph on the Very Large Telescope (VLT). In this Letter, we present the discovery and spectroscopic confirmation of PAN-BH*-1, a luminous LRD at z = 1.73 with an extreme Balmer break comparable to the strongest observed in any LRD (and, in general, any astrophysical source). The low redshift of this source enables high-resolution spectroscopy from ground-based observatories that is otherwise impossible to obtain at high redshift.\r\n\r\nThroughout this Letter, we use a ΛCDM cosmology with Ωm = 0.31, ΩΛ = 0.69, and h = 0.677 as described by Planck Collaboration et al. (2020). All the magnitudes are given in the AB system (J. B. Oke & J. E. Gunn 1983).\r\n\r\n2. Observations\r\n2.1. Photometry and Source Selection\r\nWe identified PAN-BH*-1 (ID: PAN-1115, RA, DEC: 40.015835, −1.659363 J2000) as part of a systematic search across ≈0.3 deg2 of JWST NIRCam legacy imaging comprising at least six filters of coverage (A. Weibel et al. 2026b). Notably, this dataset includes the Cycle 1 pure parallel survey PANORAMIC (PID: 2514, PIs: Williams & Oesch; C. C. Williams et al. 2025) that contributes 28 of the 35 independent lines of sight, thereby enabling the discovery of rare objects such as PAN-BH*-1 across diverse large-scale structure environments. Specifically, this source was identified in the footprint j024000m0142 of the PANORAMIC DR1,15 which is adjacent to the A370 field (G. O. Abell et al. 1989), where archival images by the Hubble Space Telescope (HST) are available from the BUFFALO survey (C. L. Steinhardt et al. 2020). The HST/ACS images were processed with grizli and also released as part of the PANORAMIC dataset.\r\n\r\nPAN-BH*-1 is in the outskirts of the A370 lensing cluster, but the magnification is only μ ≈ 1.05 according to the models from A. Niemiec et al. (2023). Throughout the rest of the paper, we report the uncorrected flux measurements, since the effect of magnification (∼5%) is negligible given the uncertainties in the observations and the lensing model.\r\n\r\nThe search strategy and full photometric selection are described in a companion paper (A. Weibel et al. 2026a). Briefly, that work presents a new selection of LRDs as a combination of a “black hole star” template (BH*; R. P. Naidu et al. 2025) embedded in a host galaxy, instead of the typically used “V-shaped” selections (e.g., D. D. Kocevski et al. 2025; V. Kokorev et al. 2024). The host galaxies are modeled using eazy’s blue_sfhz templates. The BH*s are modeled using a novel template set comprising empirical luminosity-based stacks constructed in W. Q. Sun et al. (2026), the cloudy template from R. P. Naidu et al. (2025), and by using spectra of prominent LRDs spanning the observed effective temperature range (I. Labbe et al. 2024; A. de Graaff et al. 2025a; B. Wang et al. 2026).\r\n\r\nPAN-BH*-1 stood out as one of the few sources where the BH* template effectively dominated all the light over the full wavelength range covered by NIRCam (hence the name). The redshift of PAN-BH*-1 was estimated to be zphot = 1.85. Follow-up VLT/X-Shooter spectroscopy confirmed the redshift as zspec = 1.731 (see Section 3.2).\r\n\r\nPAN-BH*-1 is also covered by archival data from the VLT with the HAWK-I camera in the Ks band (G. B. Brammer et al. 2016) and in data from the Spitzer Space Telescope in IRAC bands 1 and 3 (3.6 and 5.7 μm), and MIPS 24 μm (P. Capak 2019). PAN-BH*-1 is detected in the Ks band and in the two IRAC filters. Performing Spitzer photometry of this source is challenging due to the large point spread function (PSF) and a neighboring source, especially in the MIPS band. However, the NIRCam photometry of the neighboring source suggests it has a limited contribution to the IRAC fluxes. The details of the photometry extraction are described in Appendix A, and the measured magnitudes in Table 2.\r\n\r\n2.2. VLT/X-Shooter Spectroscopy\r\nPAN-BH*-1 was observed for 5.8 ks with the X-Shooter spectrograph (J. Vernet et al. 2011) on the VLT as a bright backup target for program 116.294D (PI: Matthee) in visitor mode on 2025 December 17. The main aim of this program was to confirm candidate LRDs at cosmic noon (Y. Ma et al. 2026). These observations confirmed the redshift through the detection of Hα at z = 1.731. A DDT program (ID 116.2AQ0; PI: Matthee) obtained additional follow-up data of PAN-BH*-1 in service mode for 26.2 ks during 2026 January 10–26, yielding a total exposure time of 8.9 hr. X-Shooter observes with three arms simultaneously, UVB, VIS, and near-infrared (NIR), covering rest-frame wavelengths of ≈0.14–0.9 μm, albeit hampered by skyline emission and telluric absorption, primarily in the rest-frame optical.\r\n\r\nThe observing conditions were clear, with a seeing ranging from 05 to 07 (median 06). The service mode observations were primarily conducted during dark nights, with some gray (FLI = 0.03–0.6, median 0.1), and a typical airmass of 1.35. We used UVB, VIS, and NIR slits with widths 10, 09, and 09, yielding a nominal resolution of R = 5400, 8900, and 5600, respectively (FWHM ∼53 km s−1 for NIR). The target acquisition was done using blind offsets from a reference star, due to the target being too faint for direct acquisition. We used a standard nodding on the slit pattern, with 4″ nod throws in an ABBA pattern, and 1″ jitters in the NIR arm to improve the sky subtraction. In each observing block of ≈1 hr, the exposure times were 700, 655, and (2×)365 s for the three arms at each nod position.\r\n\r\nThe reduction of the X-Shooter data uses a combination of EsoRex libraries16 and Python code based on the reduction pipeline employed in J. Matthee et al. (2021). Each observing block was reduced separately. We used standard stars taken during the observing night for a first-pass flux calibration. Telluric corrections were applied using the molecfit tool (A. Smette et al. 2015) implemented in the X-Shooter EsoRex pipeline. Telluric stars were observed during the visitor nights, but they were not always observed during the service mode observations in January. For those observations, we took the telluric star that was observed at the closest observing date. Based on the variation in telluric absorption among the reference stars taken during this period, we estimate the variation in the transmission and propagate the uncertainty in the telluric correction. For each observing block, we then extracted an optimally extracted 1D spectrum using the spatial profile of the Hα line, thus accounting for seeing variations and (more importantly) minor errors in the accuracy of the slit pointing. Before median combining these spectra, we normalize them by the median Hα flux of all observations to account for variations in slit losses and flux calibrations.\r\n\r\nBesides Hα (integrated S/N = 75) and Hβ (integrated S/N = 6; Section 3.2), we also detect continuum emission in the best regions in the H and K bands at 1.6 μm and 2.1 μm, respectively, with a low signal-to-noise ratio (S/N) of ∼1 per resolution element. Unfortunately, the [O iii] λλ4960, 5008 doublet is undetectable because the observed wavelengths are impacted by very strong telluric absorption. No other lines or continuum are detected in the X-Shooter spectrum.\r\n\r\n3. Properties of PAN-BH*-1\r\n3.1. Spectral Shape: A Photospheric Continuum with Strong Hα Emission\r\nThe photometric SED of PAN-BH*-1 has remarkable similarities with The Cliff (Figure 1): luminous in the rest optical, with a sudden drop toward the rest-UV around the Balmer limit, and very weak near-to-mid infrared continuum emission. With a rough extrapolation of the two HST photometric points using a power-law fit (fλ ∝ λβ), we obtain a UV slope of β = −0.1 ± 1.2, and MUV = −16.7 ± 0.7. For the rest-frame optical to NIR data, we fit a Planck blackbody law to the JWST data points, after subtracting the measured Hα flux (see Section 3.2) from the F200W photometry. The rest-optical and NIR photometry of PAN-BH*-1 is remarkably well described by a single temperature blackbody with T = 4204 K (with a best-fit ). We measure the strength of the Balmer break from the fν ratio F115W/F814W = 7 ± 1, in line with the Balmer break strengths of The Cliff (; A. de Graaff et al. 2025a)17 and MoM-BH* (7.8 ± 1.8; R. P. Naidu et al. 2025), measured from JWST/NIRSpec PRISM spectra as fν,4000–4100/fν,3620−3720. In Figure 2, we compare the Balmer break strength with the spectroscopic sample of A. de Graaff et al. (2025b), showing that out of 134 sources, only two have breaks significantly above 5. This suggests that PAN-BH*-1 has among the most extreme Balmer breaks known, although we caution that our value is derived from wide-band photometry with pivot wavelengths corresponding to 4212 and 3042 Å, respectively, rather than from spectroscopy.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 1. SED of PAN-BH*-1 Top: cutouts from all the HST and JWST images in which PAN-BH*-1 is covered. It shows a remarkably compact morphology in all the wavelengths, resolved only in the HST F606W and F814W bands (Section 3.3). Bottom: photometry from JWST/NIRCam (blue squares), HST/ACS (purple pentagons), and Spitzer/IRAC+MIPS (red hexagons, and red triangle for the 5σ upper limit). The empty square is the F200W flux after subtracting the Hα flux measured from X-Shooter spectroscopy. We show the spectrum of The Cliff for comparison (gray line), shifted to z = 1.73 and normalized to the F150W flux of PAN-BH*-1. We also show the best-fitting blackbody spectrum (blue dashed line) and the best model from the synthetic LRD atmosphere models from H. Liu et al. (2026), shifted to z = 1.73 (green line), undersampled by a factor of 500 for clarity.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nZoom InZoom OutReset image size\r\nFigure 2. Spectroscopic sample of LRDs by redshift and Balmer break strength. We plot the redshift and Balmer break strength of PAN-BH*-1, and the JWST sample from A. de Graaff et al. (2025b) (purple diamonds), and three local LRDs in X. Lin et al. (2026), for comparison. We also highlight three sources with a particularly strong Balmer break: The Cliff (A. de Graaff et al. 2025a), MoM-BH* (R. P. Naidu et al. 2025), and CAPERS-LRDz9 (A. J. Taylor et al. 2025). The Balmer break strength of the JWST spectroscopic sample is computed as fν,4000–4100/fν,3620–3720, whereas the value for PAN-BH*-1 is directly obtained from the F115W/F814W photometry.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\n3.2. Hα and Hβ Emission Lines\r\nThe Hα profile appears as a complex combination of a broad line with strong absorption close to the systemic redshift. We fit the Hα emission line with a similar model as the one used in A. Torralba et al. (2026) and J. Matthee et al. (2026). The Hα model consists of two Gaussian emission components (with narrow and intermediate line widths), and a broad symmetric exponential convolved with the intermediate profile and parameterized as in F. D’Eugenio et al. (2025a). The absorption is implemented as an opacity law defined as e−τ(λ), where τ(λ) also follows a single Gaussian velocity distribution (F. D’Eugenio et al. 2025a, 2025b; A. Torralba et al. 2026). For simplicity, we assume a covering factor of Cf = 1 for the absorbing gas. In previous works, the width of the narrow component is tied to that of [O iii], assuming both components come from the same region, often interpreted as the interstellar medium (ISM) of the host galaxy. In this case, we have no information about [O iii] due to this doublet falling in a wavelength range heavily affected by strong telluric absorption. We fit the Hα line after masking relevant skylines and strong telluric absorption bands. The fitted Hα parameters are listed in Table 1 and the best-fit model is shown in Figure 3. The absorption feature is notably strong, with an equivalent width of EWabs = −148 ± 12 Å with respect to the fitted continuum and 12.2 ± 0.2 Å if including the broad emission component. The absorption corresponds to a Balmer optical depth at the line center of , reaching roughly the continuum level. The FWHM of the single Gaussian fitted to the absorber is 283 ± 8 km s−1, and is offset from the systemic redshift by −94 ± 4 km s−1. We note that this parameterization is somewhat arbitrary, and we discuss in detail the absorber properties in Section 4.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 3. Hα spectrum, and the best fit to our fiducial model. We show the X-Shooter R ∼ 5600 spectrum of the Hα line of PAN-BH*-1, along with the best-fit to the model described in Section 3.2; total model (red solid line) and individual components (discontinuous color lines). The red wing of the line is severely affected by telluric absorption, thus the large uncertainties.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nTable 1. Properties of PAN-BH*-1\r\n\r\nParameter\tValue\tUnit\r\nWidth (FWHM; Hα)\r\nExponential\t1257 ± 27\tkm s−1\r\nIntermediate\t687 ± 43\tkm s−1\r\nNarrow\t184 ± 12\tkm s−1\r\nAbsorption\t283 ± 8\tkm s−1\r\nFlux (Hα)\r\nExponential\t643 ± 7\t10−18 erg s−1 cm−2\r\nIntermediate\t19 ± 5\t10−18 erg s−1 cm−2\r\nNarrow\t38 ± 3\t10−18 erg s−1 cm−2\r\nTotal\t522 ± 7\t10−18 erg s−1 cm−2\r\nGeneral properties\r\n(LHα/erg s−1)\t43.046 ± 0.006\t⋯\r\nEW0(Hα)\t520 ± 20\tÅ\r\nSFR(Hα, narrow)a\t2.1 ± 0.2\tM⊙ yr−1\r\nSFR(Hα, narrow)b\t3.3 ± 0.3\tM⊙ yr−1\r\nreff,UV (F606W+F814W)\t\tkpc\r\nreff,opt (F200W)\t<0.047\tkpc\r\nHα/Hβ (total)\t>9.4\t⋯\r\nHα/Hβ (narrow)\t5 ± 1\t⋯\r\nNotes. aCalibration from I. G. Kramarenko et al. (2026). bCalibration from R. C. Kennicutt & N. J. Evans (2012). SFR values calculated assuming no dust attenuation.\r\n\r\nDownload table as: \r\nASCIITypeset image\r\n\r\nThe Hβ line is marginally detected. After undersampling the spectrum by a factor 5, a hint of a weak narrow component can be identified (Figure 4), along with a tentative absorption at the same mean velocity as in Hα. We fit the best Hα model to the Hβ spectrum, only rescaling it by a multiplicative factor, and adding a flat continuum component. By doing this, we find an Hβ flux of (47 ± 8) × 10−18 erg s−1 cm−2 (S/N ≈ 6). Conservatively, we obtain a Balmer decrement of Hα/Hβ > 9.4 (at a 3σ confidence level), in line with the high decrements found for the LRD population (e.g., G. P. Nikopoulos et al. 2026; A. de Graaff et al. 2025b; J. Matthee et al. 2026). In Figure 5, we show the Hβ spectrum compared to the rescaled Hα model. By matching the best-fit Hα profile with the data at the expected observed wavelength for Hβ (±5000 km s−1), we obtain a better agreement (, BIC = 1537) than fitting a flat continuum only (, BIC = 1658) with ΔBIC = 121 ≫ 10, strongly favoring a detection of a broad Hβ emission line, and securing the spectroscopic redshift. Similarly, we fit a narrow Gaussian to Hβ with the same width and velocity as the Hα best-fit model, assuming a completely saturated absorption. We obtain a Balmer decrement for the narrow component of Hα/Hβ = 5 ± 1, which would imply a dust extinction of using a J. A. Cardelli et al. (1989) attenuation law, under the assumption of case B recombination. However, due to the low S/N of Hβ this result is only tentative, and compatible with a standard Case B value within ∼2σ.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 4. X-Shooter spectrum of Hα and Hβ of PAN-BH*-1 (blue). We compare to the spectrum of The Cliff (gray; data from JWST DDT #9433), normalized in each panel to the flux of PAN-BH*-1 in the range v ∈ (−3000, −2000) km s−1. Due to the low S/N, the Hβ spectrum of PAN-BH*-1 is rebinned to a coarser grid by a factor 5, after masking the most relevant skylines.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nZoom InZoom OutReset image size\r\nFigure 5. Hβ spectrum. The spectrum is rebinned by a factor of 10 with inverse variance flux weighting for visual clarity, due to the low S/N. We compare to the best-fit Hα model, scaled by a factor of 0.112. In the bottom panel, we show the χ residuals between the spectrum and the rescaled Hα model in black, and for only the continuum in pink (ΔBIC = 121 strongly favoring the presence of a broad Hβ line).\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\n3.3. Spatial Morphology\r\nIn order to assess whether PAN-BH*-1 is spatially resolved, we use the Bayesian profile fitting software pysersic (I. Pasha & T. B. Miller 2023)18 to fit a single Sérsic profile to the JWST and HST imaging data of PAN-BH*-1. For JWST/NIRCam, we choose F200W as the filter with the highest S/N in the short wavelength channel, benefiting from a high spatial resolution and probing rest-frame optical wavelengths. To model its PSF, we use version 2.2.0 of the stpsf software (formerly webbpsf, M. D. Perrin et al. 2014). For the two HST bands F606W and F814W, we instead construct empirical PSFs from public imaging data in the GOODS-S field following A. Weibel et al. (2024). In all three bands, we sample the posterior with the No U-turn sampler in two chains with 1000 warm-up and 2000 sampling steps each. We find that PAN-BH*-1 is unresolved with NIRCam in F200W where the effective radius converges toward the edge of the prior at 0.25 pixels. Using the 95th percentile of the posterior chains as an upper limit on the effective radius, we find a rest-optical size of reff < 47 pc.\r\n\r\nPAN-BH*-1 appears to be resolved in the HST images corresponding to rest-frame pivot 0.2 and 0.3 μm, respectively. Due to the low signal-to-noise of the F606W and F814W photometry, we fit both bands simultaneously fixing all the morphological parameters in both images. We measure physical effective radii of kpc (see Appendix B). The modest stretching by the foreground A370 lensing cluster could imply a correction of ∼10% to the measured radius (A. Niemiec et al. 2023), which we disregard given the uncertainties. These measured sizes are consistent with the typical sizes for galaxies with a stellar mass ≲ 109 M⊙ at z = 1.75 (A. van der Wel et al. 2014). These findings are consistent with the scenario of a compact LRD “engine” dominating the rest-optical light embedded in a host galaxy, whose contribution becomes significant blueward of the Balmer break (see A. P. Cloonan et al. 2026, for a relevant discussion).\r\n\r\n4. Absorber Kinematics\r\nAs described in Section 3.2, the velocity distribution of the absorber is empirically modeled with a Gaussian, which we find has a central velocity of −94 ± 4 km s−1 relative to the redshift of the narrow emission component (adopted as systemic). The absorption trough extends from negative to positive velocities with respect to the redshift of the narrow component, but also with respect to the center of the symmetric exponential wings. However, there are several degeneracies between the shape of the absorber and other components of the emission line, such as the narrow central emission (see Section 3.2). Furthermore, direct interpretation of the absorber center velocity shift is challenging in an optically thick gas with presumably complex dynamics, and it does not necessarily trace bulk motion. A more robust, physically motivated pair of quantities is the minimum and maximum absorber velocities. We define them as the values where the transmission of the Balmer absorber increases to 99%, km s−1 and km s−1. These values trace the largest velocities in the line of sight of gas with significant Balmer absorption. The absorbing trough extends over 787 ± 17 km s−1 under this definition. The values of and are relatively agnostic to the choice of the shape of the absorber, since they are determined by the wavelength where the line profile deviates from a broad, symmetric exponential profile. In Figure 6, we illustrate three proposed configurations of the velocity distribution of the absorbing gas that could explain the shape of the observed Balmer absorption, and we discuss these scenarios below.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 6. Geometric configurations for the absorber. We illustrate three scenarios that could give rise to the observed Balmer absorption in PAN-BH*-1. In scenario (a), the obscuring agent is a thick screen of gas with a certain bulk velocity, and turbulent motions produce the broadening of the absorption trough. In (b), there are two (or more) absorbers with opposite velocities in the line of sight. These first two scenarios are dynamically unstable; therefore, variability is expected in the absorption. Lastly, in (c), we observed an extended source through a disk wind with a rotational component (vϕ) in addition to the poloidal (nonazimuthal) velocity (vp). In the last scenario, the redshifted absorption is produced by streamlines that oppose the observer when projected along the line of sight, despite the fact that the gas is outflowing from the central source.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\n4.1. Unstable Gas Flows?\r\nThe fact that there is significant absorption at both negative and positive velocities with respect to the systemic redshift cannot be simply explained by an axisymmetric outflowing or inflowing wind. In the case of observing a compact object through a spherically symmetric, nonturbulent bulk flow, a classical P Cygni profile is expected, with a purely blueshifted absorption (or redshifted if the wind is infalling). The fact that we also see redshifted absorption rules out this simple scenario. In principle, turbulent motions could also produce broadening of the absorbing medium (scenario a in Figure 6). However, the required turbulent velocity dispersion σturb ≈ 120 km s−1 (from the Gaussian fit in Section 3.2) is comparable to the mean velocity of the absorption trough, meaning that turbulence dominates the gas flow. In such a case, strong variability of the absorption profile would be expected, given the typical dynamical crossing times (see Sect. 4.1 in F. D’Eugenio et al. 2025b). For example, for a radius of 1016 cm (e.g., A. Torralba et al. 2026) and a mass of 106 M⊙, the dynamical freefall time is yr. Moreover, the turbulent velocity would be highly supersonic, and the dissipation timescale would be comparable to the dynamical time (e.g., M.-M. Mac Low 1999). Alternatively, in the context of a strong Balmer absorber at z ∼ 7, F. D’Eugenio et al. (2026) recently discussed a “breathing mode” scenario with cyclic inflows and outflows along the same line of sight, with the gas being in different phases at different depths (scenario b in Figure 6; see also K. Park et al. 2017). In this case, the same arguments regarding the stability of the absorber would apply, and absorber variability is expected on observed timescales of ∼5 yr (for a source at z = 1.7), which is testable with future observations.\r\n\r\n4.2. The Case for the Disk Wind Hypothesis\r\nAn alternative, dynamically stable scenario is a disk wind configuration (scenario c in Figure 6). Here, the wind would be launched from a thick disk near the central engine, which we speculate could be the source of the optical continuum emission (e.g., H. Liu et al. 2025, 2026; L. Zwick et al. 2025; Y.-X. Chen et al. 2026). A rotating disk would imprint to the wind an azimuthal velocity component (vϕ). Observations at specific lines of sight, particularly for high inclination angles (close to edge-on) where the rotational component dominates the poloidal velocity, can give rise to both blueshifted and redshifted absorption features (D. Proga et al. 2000; P. B. Hall et al. 2002, 2013; D. Proga & T. R. Kallman 2004; M. Giustini & D. Proga 2012). Most observed LRDs have blueshifted P Cygni–like absorbers (J. Matthee et al. 2026), which can be naively interpreted as a uniformly expanding shell. The low incidence of redshifted Balmer absorbers in LRD spectra (e.g., I. Labbe et al. 2024; A. de Graaff et al. 2025a; F. D’Eugenio et al. 2025b, 2026; Y. Ma et al. 2026) can therefore be explained by the requirement of high inclination angles to observe such features (see also A. Sneppen et al. 2026). Such a picture is broadly in line with disk wind models for AGN with broad absorption lines (e.g., P. B. Hall et al. 2002; H. Zhou et al. 2019) and around stars with circumstellar disks (e.g., J. Erkal et al. 2022), such as accreting T Tauri stars (S. Edwards et al. 2006) or cataclysmic variables (D. Proga 2003).\r\n\r\n4.3. Implications of Rotating Winds for the Emission Lines of LRDs\r\nThe disk wind hypothesis would imply that a photosphere in the shape of a rotating disk is the source of the optical continuum emission, and drives winds that can explain the observed absorption trough. Emission lines originating in a thin rotating disk would have a double-peaked profile in the idealized case (for most inclination angles), but this is not necessarily true if the disk is not sufficiently thin (e.g., N. Murray & J. Chiang 1997), for instance, in the case of a puffed-up disk associated with super-Eddington accretion (e.g., H. Liu et al. 2026). In addition, most line emission would not be produced directly at the base of the disk, but slightly outside (e.g., via collisional cooling or residual recombination; A. Torralba et al. 2026), where the rotational velocity is lower, and the dynamics are complex (e.g., G. A. Shields 1977).\r\n\r\nThe Balmer lines of most LRDs are dominated by broad, symmetric exponential components that are associated with broadening by electron scattering (e.g., V. Rusakov et al. 2026; J. Matthee et al. 2026). For PAN-BH*-1, the Hα line profile of PAN-BH*-1 is compatible with a broad exponential profile emerging through a dense wind where the absorption trough is produced. In dense gas with a large column density of neutral hydrogen, and optically thick to Balmer transitions (NHI,2s ≳ 1014 cm−2), resonant scattering effects become important. Crucially, resonant scattering impacts Hα and Hβ differently (e.g., S.-J. Chang et al. 2026), hence the 3D radiative transfer and photon redistribution of both lines may produce different profiles (see, e.g., Figure 2 in D. Proga 2003). Therefore, the empirical fitting and interpretation of the absorption profiles becomes nontrivial. Dedicated radiative transfer modeling is necessary to study such effects, and they can be tested in other emission lines with high optical depth, such as He i λ10830 Å, or resonant lines like C iv λ1550.\r\n\r\n5. Implications for the Galaxy and Black Hole Masses\r\n5.1. Properties of the Host Galaxy\r\nAssuming that the narrow component of Hα corresponds to ISM emission in the host galaxy, we compute the associated star formation rate using the local calibration from R. C. Kennicutt & N. J. Evans (2012) and assuming no dust attenuation. We obtain SFR(Hα) = 3.3 ± 0.3 M⊙ yr−1. A somewhat lower value of SFR(Hα) = 2.1 ± 0.2 M⊙ yr−1 is obtained using the high-redshift (z ≳ 4) calibrations in I. G. Kramarenko et al. (2026), which might be more appropriate for a young dwarf galaxy with a bursty star formation history. The star formation rates are low, but in line with a main-sequence galaxy with (extrapolating the relation from J. S. Speagle et al. 2014). Assuming zero dust attenuation, the UV absolute magnitude (MUV = −16.7 ± 0.7; Section 3.1) would imply SFR(UV) = 0.18 ± 0.12 M⊙ yr−1 (R. C. Kennicutt & N. J. Evans 2012). The discrepancy between the UV and Hα inferred star formation rate suggests there is some amount of dust attenuation in the host galaxy.\r\n\r\nWe derive a dynamical mass from the width of the narrow component Hα line and the estimated UV size as , adopting the empirical virial correction K(n)K(q) from A. van der Wel et al. (2022), where K(n) and K(q) are functions of the best-fit ellipticity and Sérsic index (see Appendix B). Adopting a Mdyn/M* factor of 40 as found by A. de Graaff et al. (2024) for dwarf galaxies at high redshift, we infer a stellar mass of . However, the Mdyn/M* is very uncertain in this regime, and the uncertainty can span over 1 dex (A. Saldana-Lopez et al. 2025). We advise caution in interpreting this result, as there are large uncertainties in the measurements of the narrow Hα component, the HST morphology, and the empirical relations used.\r\n\r\nAs discussed in Section 4, the absorption profile is compatible with broadening by a rotating disk wind, and numerical modeling of such configurations often predicts a narrow component arising from increased transmission due to purely kinematic effects in the wind geometry (D. Proga et al. 2000; D. Proga 2003; D. Proga & T. R. Kallman 2004). This would be an alternative explanation for at least part of the narrow component flux. On the other hand, most LRDs present narrow [O iii] emission that is often associated with the host galaxy. Indeed, the ionized gas producing [O iii] emission should have associated emission in the Hα and higher-order Balmer lines. However, constraining this component largely depends on the assumptions on dust attenuation or ISM conditions, and requires very high S/N and resolution data. Deep, space-based follow-up observations of PAN-BH*-1 would be very constraining for the wind kinematics (e.g., by the joint analysis of Hβ) and to assess whether a narrow component comes from a host galaxy (e.g., by comparing to a narrow Hβ component or [O iii] λλ4960, 5008).\r\n\r\n5.2. Black Hole Mass From Photosphere Models\r\nThe general physical setup of LRDs is an open debate, and their masses are a major unknown. Due to the multiple differences with respect to the classical AGN population, the validity of standard virial calibrations has been questioned (e.g., V. Rusakov et al. 2026; J. E. Greene et al. 2026; A. Sneppen et al. 2026; A. Torralba et al. 2026, although see, e.g., M. Brazzini et al. 2025, 2026; J. Scholtz et al. 2026 for an alternative interpretation).\r\n\r\nOne can obtain a mass estimate assuming a system in radiative equilibrium with Lbol/LEdd = 1 (e.g., H. Umeda et al. 2026); this yields a total mass of ≈106 M⊙, using the bolometric luminosity from integrating the best-fit blackbody in Section 3.1. Recently, H. Liu et al. (2026) developed a synthetic spectral library of LRD atmosphere models. In these models, the density of the photosphere is regulated by the net surface gravity of an optically thick atmosphere, enabling constraints on the mass of the system. We fit the JWST photometry of PAN-BH*-1 using the models from H. Liu et al. (2026), assuming a negligible contribution from a host galaxy to the optical continuum. The best-fit model has effective temperature Teff = 4800 K, surface gravity , and metallicity (; see Figure 1). The best-fit implies a total mass of the system (BH plus gas) of (Equation (6) in H. Liu et al. 2026, assuming hydrostatic equilibrium). For the second and third best fits, we obtain and −2, respectively (, respectively; with the same metallicity and effective temperature), which would imply lower limits to the system mass between and 4. The bolometric luminosity of PAN-BH*-1 (from the integral of the best-fit green curve in Figure 1) implies an Eddington luminosity ratio of L/LEdd ≲ 13, assuming the best-fit mass from the H. Liu et al. (2026) models. The elevated Eddington ratio is in line with the hypothesis of a radiation-driven wind discussed in Section 4, and allows for somewhat larger system masses. The low masses obtained with this model, combined with the stellar mass inferred from dynamical arguments for the host galaxy (Section 3.3) set lower limits to the BH-to-stellar mass ratio of MBH/M* ≳ 10−4–10−2, which are compatible with the relations observed in the Local Universe, within the large uncertainties (A. E. Reines & M. Volonteri 2015).\r\n\r\n6. Conclusions\r\nIn this Letter, we presented the discovery and spectroscopic confirmation of PAN-BH*-1, an LRD with an extreme Balmer break at z = 1.731. The strength of the Balmer break (F115W/F814W = 7 ± 1) is comparable to the most extreme LRDs known, The Cliff (A. de Graaff et al. 2025a) and MoM-BH* (R. P. Naidu et al. 2025). We summarize the observations and our main conclusions as follows.\r\n\r\n\r\n1. \r\nWe obtained deep VLT/X-Shooter spectroscopy of PAN-BH*-1. The Hα emission line is luminous and broad (LHα = 1043 erg s−1), and has an unusually strong absorption. Hβ is detected with an S/N ≈ 6, and we conservatively estimate a lower limit for the Balmer decrement of Hα/Hβ > 9.4 (at a 3σ confidence level), in line with other LRDs in the literature (e.g., A. de Graaff et al. 2025b; G. P. Nikopoulos et al. 2026).\r\n2. \r\nThe absorption trough spans from −520 to 267 km s−1 (at a transmission level of 99%). We interpret the presence of blue- and redshifted absorption as produced by a disk wind, analogous to those analyzed in the context of broad absorption line quasars or accreting stars. This hypothesis would imply that the source of the optical continuum is likely a thick photospheric disk.\r\n3. \r\nWe detect a narrow Hα component (FWHM = 184 ± 12 km s−1), which we interpret as probing a host galaxy with M* ≈ 108 M⊙ and SFR = 2–3 M⊙. This interpretation is in line with the extended rest-NUV morphology measured in the HST bands (\r\n kpc).\r\n4. \r\nBy fitting the synthetic atmosphere models of H. Liu et al. (2026), we estimate a system mass (BH+envelope) of 104–106 M⊙. The inferred masses, together with the stellar mass inferred from morphology and narrow emission line dynamics, imply BH-to-stellar mass ratios of 10−2–10−4, close to the extrapolated trend in the local Universe (A. E. Reines & M. Volonteri 2015).\r\n5. \r\nThe confirmation of this source at cosmic noon (magnitude of ≈22 in the K band, Hα flux ≈5 × 10−16 erg s−1 cm−2) proves the feasibility of detecting extreme LRDs at such epochs with wide-area spectroscopic surveys like Euclid or the forthcoming Nancy Grace Roman Space Telescope.\r\n\r\nAcknowledgments\r\nA.T. thanks Debasish Dutta and Tamara Bogdanović for useful conversations about stellar and AGN winds.\r\n\r\nWe thank the scientific referee for the useful and constructive feedback, which helped improve the quality of this paper.\r\n\r\nJ.M. and A.T. acknowledge funding by the European Union (ERC, AGENTS, 101076224). The work of CCW is supported by NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. A.P.C. warmly acknowledges the support of the National Science Foundation through the NSF Graduate Research Fellowship Program. A.d.G. acknowledges support from a Clay Fellowship awarded by the Smithsonian Astrophysical Observatory.\r\n\r\nBased on observations made with ESO Telescopes at the Paranal Observatory under program IDs 116.294D and 116.2AQ0.\r\n\r\nThis work is based in part on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with programs #2514 and #9433. C.C.W. gratefully acknowledges support for program JWST-GO-2514 provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127. The authors acknowledge the team led by co-PIs R. Maiolino and F. D’Eugenio for developing their observing program with a zero-exclusive-access period.\r\n\r\nThis research is based on observations made with the NASA/ESA Hubble Space Telescope obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5–26555. These observations are associated with program #15117.\r\n\r\nThe JWST and HST data presented in this article were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The specific observations analyzed can be accessed via doi:10.17909/ydwx-st06.\r\n\r\nThis work is based in part on observations made with the Spitzer Space Telescope, which was operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. The Spitzer data used in this work can be found in doi:10.26131/IRSA3.\r\n\r\nThis work was supported by the International Space Science Institute (ISSI) in Bern, through ISSI International Team project #25-659 “Little Red Dots, Big Open Questions.”\r\n\r\nJWST cartoon in Figure 6, credit: NASA.\r\n\r\nFacilities: VLT:Kueyen - Very Large Telescope (Kueyen) (X-Shooter), VLT:Yepun (HAWK-I), JWST - James Webb Space Telescope (NIRCam, NIRspec), HST - Hubble Space Telescope satellite (ACS), Spitzer - Spitzer Space Telescope satellite (IRAC, MIPS) - .\r\n\r\nSoftware: astropy (Astropy Collaboration et al. 2013, 2018; Astropy Collaboration et al. 2022), NumPy (C. R. Harris et al. 2020), SciPy (P. Virtanen et al. 2020), pysersic (I. Pasha & T. B. Miller 2023), stpsf (M. D. Perrin et al. 2014), lmfit (M. Newville et al. 2014), EsoRex (ESO CPL Development Team 2015), Claude (used for Python coding; https://claude.ai/), SEP (K. Barbary 2016).","volume":1005,"project":[{"_id":"bd9b2118-d553-11ed-ba76-db24564edfea","name":"Young galaxies as tracers and agents of cosmic reionization","grant_number":"101076224"}]},{"OA_type":"gold","keyword":["Galaxy evolution","Chemical enrichment","Metallicity","Galaxy abundances","Scaling relations"],"article_number":"159","das_tickbox":"1","author":[{"last_name":"Lewis","full_name":"Lewis, Zach","first_name":"Zach"},{"first_name":"Michael V.","full_name":"Maseda, Michael V.","last_name":"Maseda"},{"first_name":"Anna","full_name":"De Graaff, Anna","last_name":"De Graaff"},{"last_name":"Leja","first_name":"Joel","full_name":"Leja, Joel"},{"last_name":"Wang","first_name":"Bingjie","full_name":"Wang, Bingjie"},{"last_name":"Rix","first_name":"Hans Walter","full_name":"Rix, Hans Walter"},{"full_name":"Mcconachie, Ian","first_name":"Ian","last_name":"Mcconachie"},{"last_name":"Cleri","full_name":"Cleri, Nikko J.","first_name":"Nikko J."},{"last_name":"Bezanson","first_name":"Rachel","full_name":"Bezanson, Rachel"},{"first_name":"Leindert A.","full_name":"Boogaard, Leindert A.","last_name":"Boogaard"},{"full_name":"Brammer, Gabriel","first_name":"Gabriel","last_name":"Brammer"},{"last_name":"Greene","full_name":"Greene, Jenny E.","first_name":"Jenny E."},{"first_name":"Michaela","full_name":"Hirschmann, Michaela","last_name":"Hirschmann"},{"last_name":"Katz","full_name":"Katz, Harley","first_name":"Harley"},{"last_name":"Labbé","full_name":"Labbé, Ivo","first_name":"Ivo"},{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","full_name":"Matthee, Jorryt J","orcid":"0000-0003-2871-127X","first_name":"Jorryt J","last_name":"Matthee"},{"first_name":"Tim B.","full_name":"Miller, Tim B.","last_name":"Miller"},{"full_name":"Naidu, Rohan P.","first_name":"Rohan P.","last_name":"Naidu"},{"first_name":"Pascal A.","full_name":"Oesch, Pascal A.","last_name":"Oesch"},{"last_name":"Setton","first_name":"David J.","full_name":"Setton, David J."},{"full_name":"Suess, Katherine A.","first_name":"Katherine A.","last_name":"Suess"},{"full_name":"Weibel, Andrea","first_name":"Andrea","last_name":"Weibel"},{"first_name":"Katherine E.","full_name":"Whitaker, Katherine E.","last_name":"Whitaker"},{"first_name":"Christina C.","full_name":"Williams, Christina C.","last_name":"Williams"}],"abstract":[{"text":"The correlation between galaxy stellar mass and gas-phase metallicity, known as the mass–metallicity relation (MZR), gives key insights into the processes that govern galaxy evolution. However, unquantified observational and selection biases can result in systematic errors in attempts to recover the intrinsic MZR, particularly at higher redshifts. We characterize the MZR at z ∼ 3–6 within a fully Bayesian framework using JWST/NIRSpec spectra of 191 galaxies from the RUBIES survey. We forward model the observed mass–metallicity surface using prospector-generated spectra to account for two selection biases: the survey selection function and the success in observing high signal-to-noise ratio emission lines. We demonstrate that the RUBIES selection function, based on F444W magnitude and F150W – F444W color, has a negligible effect on our measured MZR. A correct treatment of the non-Gaussian metallicity uncertainties from strong-line calibrations lowers the derived MZR normalization by 0.2 dex and flattens the slope by ∼20%; forward modeling the effect of emission line observability steepens the slope by ∼15%. Both of these biases must be taken into account in order to properly measure the intrinsic MZR. This novel forward-modeling process motivates careful consideration of selection functions in future surveys, and paves the way for robust, high-redshift chemical enrichment studies that trace the evolution of the MZR across cosmic time.","lang":"eng"}],"publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"PlanS_conform":"1","day":"10","fulldoi":"https://doi.org/10.3847/1538-4357/ae7bfc","ddc":["520"],"publisher":"IOP Publishing","file_date_updated":"2026-07-13T07:35:16Z","doi":"10.3847/1538-4357/ae7bfc","OA_place":"publisher","oa":1,"article_processing_charge":"Yes","title":"The mass–metallicity relation and its observational effects at z ∼ 3–6","scopus_import":"1","publication":"The Astrophysical Journal","DOAJ_listed":"1","year":"2026","month":"07","_id":"22264","status":"public","issue":"2","external_id":{"arxiv":["2512.03134"]},"citation":{"short":"Z. Lewis, M.V. Maseda, A. De Graaff, J. Leja, B. Wang, H.W. Rix, I. Mcconachie, N.J. Cleri, R. Bezanson, L.A. Boogaard, G. Brammer, J.E. Greene, M. Hirschmann, H. Katz, I. Labbé, J.J. Matthee, T.B. Miller, R.P. Naidu, P.A. Oesch, D.J. Setton, K.A. Suess, A. Weibel, K.E. Whitaker, C.C. Williams, The Astrophysical Journal 1005 (2026).","ieee":"Z. Lewis et al., “The mass–metallicity relation and its observational effects at z ∼ 3–6,” The Astrophysical Journal, vol. 1005, no. 2. IOP Publishing, 2026.","apa":"Lewis, Z., Maseda, M. V., De Graaff, A., Leja, J., Wang, B., Rix, H. W., … Williams, C. C. (2026). The mass–metallicity relation and its observational effects at z ∼ 3–6. The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae7bfc","mla":"Lewis, Zach, et al. “The Mass–Metallicity Relation and Its Observational Effects at z ∼ 3–6.” The Astrophysical Journal, vol. 1005, no. 2, 159, IOP Publishing, 2026, doi:10.3847/1538-4357/ae7bfc.","ista":"Lewis Z, Maseda MV, De Graaff A, Leja J, Wang B, Rix HW, Mcconachie I, Cleri NJ, Bezanson R, Boogaard LA, Brammer G, Greene JE, Hirschmann M, Katz H, Labbé I, Matthee JJ, Miller TB, Naidu RP, Oesch PA, Setton DJ, Suess KA, Weibel A, Whitaker KE, Williams CC. 2026. The mass–metallicity relation and its observational effects at z ∼ 3–6. The Astrophysical Journal. 1005(2), 159.","ama":"Lewis Z, Maseda MV, De Graaff A, et al. The mass–metallicity relation and its observational effects at z ∼ 3–6. The Astrophysical Journal. 2026;1005(2). doi:10.3847/1538-4357/ae7bfc","chicago":"Lewis, Zach, Michael V. Maseda, Anna De Graaff, Joel Leja, Bingjie Wang, Hans Walter Rix, Ian Mcconachie, et al. “The Mass–Metallicity Relation and Its Observational Effects at z ∼ 3–6.” The Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae7bfc."},"acknowledgement":"This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with program ID 4233. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under grant No. 2137424 as well as work supported by NASA under Award No. 2025_3-0, issued through the Wisconsin Space Grant Consortium, and JWST-GO-4233. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration. Support for program ID 4233 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127. M.V.M. is supported by the National Science Foundation via grant AAG 2205519. A.d.G. acknowledges support from a Clay Fellowship awarded by the Smithsonian Astrophysical Observatory. T.B.M. was supported by a CIERA Fellowship. Part of the computations for this research were performed on the Pennsylvania State University’s Institute for Computational and Data Sciences’ Roar supercomputer. Some/all of the data presented in this article were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The specific observations analyzed can be accessed via doi:10.17909/qk5z-7p30. The scripts used to generate the data and results in this work can be found in Zenodo at doi:10.5281/zenodo.20513668 and GitHub \r\nhttps://github.com/zachlewis99/rubies_mzr ","volume":1005,"date_updated":"2026-07-13T07:40:41Z","supplementarymaterial":"no","department":[{"_id":"JoMa"}],"publication_status":"published","file":[{"content_type":"application/pdf","file_name":"2026_AstrophysicalJour_Lewis.pdf","success":1,"date_updated":"2026-07-13T07:35:16Z","file_id":"22273","checksum":"9b13fbbc5e5e921c04676ebc532d9c42","relation":"main_file","access_level":"open_access","date_created":"2026-07-13T07:35:16Z","file_size":1854628,"creator":"dernst"}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","date_created":"2026-07-12T22:02:17Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","language":[{"iso":"eng"}],"intvolume":" 1005","quality_controlled":"1","arxiv":1,"has_accepted_license":"1","dataavailabilitystatement":"The specific observations analyzed can be accessed via doi:10.17909/qk5z-7p30. The scripts used to generate the data and results in this work can be found in Zenodo at doi:10.5281/zenodo.20513668 and GitHub https://github.com/zachlewis99/rubies_mzr","type":"journal_article","date_published":"2026-07-10T00:00:00Z","researchdata_availability":"yes"},{"volume":1005,"acknowledgement":"We would like to thank the referee for their careful reading of the manuscript and their constructive comments that helped improve the paper. N.B.V. would like to thank K. Belkacem and J. Philidet for helpful discussions. N.B.V. is supported by STFC grant ST/Y002164/1. A.L.S. acknowledges support from the European Research Council (ERC) under the Horizon Europe program (Synergy grant agreement 101071505: 4D-STAR) from the CNES SOHO-GOLF and PLATO grants at CEA-DAp, and from ATPS (CNRS/INSU). Part of this work was supported by the ERC grant No. 787361-COBOM. R.H.D.T. acknowledges support from NASA grants 80NSSC24K0895 and 80NSSC23K1517, and NSF grant 2407636. A.L. is supported by ERC Starting Grant 101165631 (“Calcifer”). The authors would like to acknowledge the use of the University of Exeter High-Performance Computing (HPC) facility, ISCA, in carrying out this work. This work used the DiRAC Memory Intensive service (Cosma8) at Durham University, managed by the Institute for Computational Cosmology, and the DiRAC Data Intensive service (DIaL3) at the University of Leicester, managed by the University of Leicester Research Computing Service. These facilities are managed on behalf of the STFC DiRAC HPC (www.dirac.ac.uk). The DiRAC services at Durham and Leicester were funded by BEIS, UKRI, and STFC capital funding, and STFC operations grants. The service at Durham received funding from Durham University. DiRAC is part of the UKRI Digital Research Infrastructure.","project":[{"name":"Unveiling the mysteries of stellar dynamics: a pioneering journey in magnetoasteroseismology","grant_number":"101165631","_id":"914d8549-16d5-11f0-9cad-bbe6324c93a9"}],"citation":{"chicago":"De Vries, Nils B., Arthur Le Saux, Isabelle Baraffe, Thomas Guillet, Richard H.D. Townsend, Armand Leclerc, and Adrien Morison. “Revealing Mixed Modes in Compressible Hydrodynamical Simulations of Red Giant Stars.” The Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae7a3c.","short":"N.B. De Vries, A. Le Saux, I. Baraffe, T. Guillet, R.H.D. Townsend, A. Leclerc, A. Morison, The Astrophysical Journal 1005 (2026).","ieee":"N. B. De Vries et al., “Revealing mixed modes in compressible hydrodynamical simulations of red giant stars,” The Astrophysical Journal, vol. 1005, no. 2. IOP Publishing, 2026.","apa":"De Vries, N. B., Le Saux, A., Baraffe, I., Guillet, T., Townsend, R. H. D., Leclerc, A., & Morison, A. (2026). Revealing mixed modes in compressible hydrodynamical simulations of red giant stars. The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae7a3c","mla":"De Vries, Nils B., et al. “Revealing Mixed Modes in Compressible Hydrodynamical Simulations of Red Giant Stars.” The Astrophysical Journal, vol. 1005, no. 2, 154, IOP Publishing, 2026, doi:10.3847/1538-4357/ae7a3c.","ista":"De Vries NB, Le Saux A, Baraffe I, Guillet T, Townsend RHD, Leclerc A, Morison A. 2026. Revealing mixed modes in compressible hydrodynamical simulations of red giant stars. The Astrophysical Journal. 1005(2), 154.","ama":"De Vries NB, Le Saux A, Baraffe I, et al. Revealing mixed modes in compressible hydrodynamical simulations of red giant stars. The Astrophysical Journal. 2026;1005(2). doi:10.3847/1538-4357/ae7a3c"},"external_id":{"arxiv":["2606.07125"]},"issue":"2","type":"journal_article","dataavailabilitystatement":"The kinetic energies and surface velocities shown in Figure 4, as well as the underlying spectral data of this work, can be found in a Zenodo repository at doi:10.5281/zenodo.18661976.","has_accepted_license":"1","date_published":"2026-07-10T00:00:00Z","researchdata_availability":"yes","language":[{"iso":"eng"}],"oa_version":"Published Version","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_created":"2026-07-12T22:02:17Z","intvolume":" 1005","arxiv":1,"quality_controlled":"1","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"file":[{"file_name":"2026_AstrophysicalJour_deVries.pdf","content_type":"application/pdf","success":1,"date_updated":"2026-07-13T08:14:01Z","checksum":"d32061d2341bac3adeb404975c6bd59e","relation":"main_file","file_id":"22275","access_level":"open_access","date_created":"2026-07-13T08:14:01Z","creator":"dernst","file_size":14866194}],"article_type":"original","supplementarymaterial":"yes","date_updated":"2026-07-13T08:16:25Z","department":[{"_id":"LiBu"}],"publication_status":"published","abstract":[{"text":"Mixed modes are observed in many low-mass evolved stars. They provide information about core rotation rates of these stars, which are lower than predicted by stellar evolution models. The mixed modes themselves have been invoked as an angular momentum (AM) transport mechanism, but estimating their transport efficiency requires knowledge of their amplitudes. We constrain, for the first time, the mixed-mode amplitudes in 2D hydrodynamical simulations of a 1.3M⊙ red giant using the code MUSIC. We perform two simulations with outer radial truncations at fractional radii ro/r⋆ = 0.90 and 0.98. We compare the modes in the simulation with those found using both GYRE and a Dedalus eigenvalue solver. Excellent frequency agreement is found for all p-dominated modes, with minor discrepancies for g-dominated modes, especially in the frequency range [60, 240] μHz. We find excellent eigenfunction agreement for all modes except those in this frequency range. According to empirical predictions, the largest kinetic energies are located around Vmax= 312.μHz, but in both simulations, the modes with frequencies of ν < 50 μHz have the largest kinetic energies. In the simulation with r/r⋆ = 0.98, the simulated modes have extrapolated surface velocities comparable to the empirical predictions, with the highest surface velocities in a bell-shaped curve peaking around ν = 700 μHz. The extrapolated surface velocities of the low-frequency modes are small and thus hard to observe, but their large kinetic energies deeper in the interior could significantly impact AM transport, which has not yet been investigated.","lang":"eng"}],"author":[{"last_name":"De Vries","first_name":"Nils B.","full_name":"De Vries, Nils B."},{"full_name":"Le Saux, Arthur","first_name":"Arthur","last_name":"Le Saux"},{"full_name":"Baraffe, Isabelle","first_name":"Isabelle","last_name":"Baraffe"},{"last_name":"Guillet","first_name":"Thomas","full_name":"Guillet, Thomas"},{"first_name":"Richard H.D.","full_name":"Townsend, Richard H.D.","last_name":"Townsend"},{"full_name":"Leclerc, Armand","id":"2a1fb1fc-f373-11ef-901a-87cee43a1217","first_name":"Armand","last_name":"Leclerc"},{"full_name":"Morison, Adrien","first_name":"Adrien","last_name":"Morison"}],"keyword":["Stellar physics","Stellar interiors","Asteroseismology","Stellar oscillations","Hydrodynamical simulations"],"OA_type":"gold","das_tickbox":"1","article_number":"154","DOAJ_listed":"1","publication":"The Astrophysical Journal","status":"public","_id":"22262","month":"07","year":"2026","article_processing_charge":"Yes","oa":1,"scopus_import":"1","title":"Revealing mixed modes in compressible hydrodynamical simulations of red giant stars","fulldoi":"https://doi.org/10.3847/1538-4357/ae7a3c","ddc":["520"],"doi":"10.3847/1538-4357/ae7a3c","OA_place":"publisher","file_date_updated":"2026-07-13T08:14:01Z","publisher":"IOP Publishing","publication_identifier":{"issn":["0004-637X"],"eissn":["1538-4357"]},"day":"10","PlanS_conform":"1"},{"abstract":[{"lang":"eng","text":"Climate change is significantly altering regional precipitation patterns across Europe and the Mediterranean. We analyze daily precipitation distribution changes in a 15-member Euro-CORDEX ensemble, through a diagnostic framework that separates occurrence changes, wet-days intensity shifts and distortions. At +4 ∘C global warming, Northern Europe shows a robust intensification of precipitation, driven by both higher occurrence and stronger events. Conversely, the Mediterranean exhibits a dominant drying signal, primarily due to fewer wet-days, which impacts daily precipitation distribution even for heavy rainfall. Transitional zones in the northern Mediterranean reveal “U-shape” regimes, with rising extremes but declining moderate rain. Comparing with ERA5 reanalysis over the past, low model agreement in the south highlights higher uncertainty in the Mediterranean region. The timing of robust signal emergence varies: Northern Europe shows robust patterns from +1 ∘C, while the Mediterranean exhibits delays until +3-4 ∘C. These findings are essential for informing risk-based adaptation strategies."}],"author":[{"first_name":"Julie","full_name":"André, Julie","last_name":"André"},{"last_name":"Chiabrando","full_name":"Chiabrando, Nicolas","first_name":"Nicolas"},{"last_name":"Muller","full_name":"Muller, Caroline J","id":"f978ccb0-3f7f-11eb-b193-b0e2bd13182b","orcid":"0000-0001-5836-5350","first_name":"Caroline J"},{"last_name":"Drobinski","full_name":"Drobinski, Philippe","first_name":"Philippe"},{"first_name":"Fabio","full_name":"D’Andrea, Fabio","last_name":"D’Andrea"}],"article_number":"572","das_tickbox":"1","OA_type":"gold","year":"2026","status":"public","_id":"22261","month":"07","DOAJ_listed":"1","publication":"Communications Earth and Environment","title":"Distinct regimes of precipitation changes across Europe and the Mediterranean under global warming","scopus_import":"1","oa":1,"article_processing_charge":"Yes","publisher":"Springer Nature","file_date_updated":"2026-07-13T07:12:35Z","doi":"10.1038/s43247-026-03519-7","OA_place":"publisher","fulldoi":"https://doi.org/10.1038/s43247-026-03519-7","ddc":["550"],"day":"06","publication_identifier":{"eissn":["2662-4435"]},"project":[{"call_identifier":"H2020","_id":"629205d8-2b32-11ec-9570-e1356ff73576","grant_number":"805041","name":"Organization of CLoUdS, and implications of Tropical cyclones and for the Energetics of the tropics, in current and waRming climate"}],"acknowledgement":"J.A. gratefully acknowledges the JSPS postdoctoral fellowship (Japan Society for Promotion of Science, grant number P25709). C.J.M. gratefully acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Project CLUSTER, Grant Agreement No. 805041). The authors also thank Samuel Somot (Centre National de Recherches Météorologiques, Toulouse) and Juliette Blanchet (Institut des Géosciences de l’Environnement, Grenoble) for their fruitful discussions on the project.","volume":7,"citation":{"chicago":"André, Julie, Nicolas Chiabrando, Caroline J Muller, Philippe Drobinski, and Fabio D’Andrea. “Distinct Regimes of Precipitation Changes across Europe and the Mediterranean under Global Warming.” Communications Earth and Environment. Springer Nature, 2026. https://doi.org/10.1038/s43247-026-03519-7.","short":"J. André, N. Chiabrando, C.J. Muller, P. Drobinski, F. D’Andrea, Communications Earth and Environment 7 (2026).","ieee":"J. André, N. Chiabrando, C. J. Muller, P. Drobinski, and F. D’Andrea, “Distinct regimes of precipitation changes across Europe and the Mediterranean under global warming,” Communications Earth and Environment, vol. 7. Springer Nature, 2026.","apa":"André, J., Chiabrando, N., Muller, C. J., Drobinski, P., & D’Andrea, F. (2026). Distinct regimes of precipitation changes across Europe and the Mediterranean under global warming. Communications Earth and Environment. Springer Nature. https://doi.org/10.1038/s43247-026-03519-7","mla":"André, Julie, et al. “Distinct Regimes of Precipitation Changes across Europe and the Mediterranean under Global Warming.” Communications Earth and Environment, vol. 7, 572, Springer Nature, 2026, doi:10.1038/s43247-026-03519-7.","ama":"André J, Chiabrando N, Muller CJ, Drobinski P, D’Andrea F. Distinct regimes of precipitation changes across Europe and the Mediterranean under global warming. Communications Earth and Environment. 2026;7. doi:10.1038/s43247-026-03519-7","ista":"André J, Chiabrando N, Muller CJ, Drobinski P, D’Andrea F. 2026. Distinct regimes of precipitation changes across Europe and the Mediterranean under global warming. Communications Earth and Environment. 7, 572."},"ec_funded":1,"date_published":"2026-07-06T00:00:00Z","researchdata_availability":"yes","has_accepted_license":"1","type":"journal_article","dataavailabilitystatement":"ERA5 reanalysis and Euro-CORDEX simulations are publicly available from https://doi.org/10.24381/cds.143582cf and https://cordex.org/data-access/esgf/. The custom code developed and used for this paper can be accessed through Zenodo, https://doi.org/10.5281/zenodo.18995401.","quality_controlled":"1","intvolume":" 7","date_created":"2026-07-12T22:02:16Z","oa_version":"Published Version","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"article_type":"original","file":[{"access_level":"open_access","creator":"dernst","file_size":3870924,"date_created":"2026-07-13T07:12:35Z","success":1,"file_name":"2026_CommEarthEnvironment_Andre.pdf","content_type":"application/pdf","checksum":"fd8f57cbe180f7a4d49ab17b3571ad2b","relation":"main_file","file_id":"22272","date_updated":"2026-07-13T07:12:35Z"}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"publication_status":"published","department":[{"_id":"CaMu"}],"date_updated":"2026-07-13T07:13:21Z","supplementarymaterial":"yes"},{"citation":{"chicago":"El-Badry, Kareem, Klaus Werner, Ken J. Shen, Jay Strader, Antonio C. Rodriguez, Jiwon Jesse Han, Vedant Chandra, et al. “A Systematic Survey for Hypervelocity Runaways from Thermonuclear Supernovae.” The Open Journal of Astrophysics. Maynooth Academic Publishing, 2026. https://doi.org/10.33232/001c.164326.","apa":"El-Badry, K., Werner, K., Shen, K. J., Strader, J., Rodriguez, A. C., Han, J. J., … Hollands, M. A. (2026). A systematic survey for hypervelocity runaways from thermonuclear supernovae. The Open Journal of Astrophysics. Maynooth Academic Publishing. https://doi.org/10.33232/001c.164326","mla":"El-Badry, Kareem, et al. “A Systematic Survey for Hypervelocity Runaways from Thermonuclear Supernovae.” The Open Journal of Astrophysics, vol. 9, Maynooth Academic Publishing, 2026, doi:10.33232/001c.164326.","ista":"El-Badry K, Werner K, Shen KJ, Strader J, Rodriguez AC, Han JJ, Chandra V, Chomiuk L, Vanderbosch ZP, Blomberg L, Yamaguchi N, Nagarajan P, Caiazzo I, van Roestel JC, Glanz H, Wong TLS, Bhat A, Hollands MA. 2026. A systematic survey for hypervelocity runaways from thermonuclear supernovae. The Open Journal of Astrophysics. 9.","ama":"El-Badry K, Werner K, Shen KJ, et al. A systematic survey for hypervelocity runaways from thermonuclear supernovae. The Open Journal of Astrophysics. 2026;9. doi:10.33232/001c.164326","short":"K. El-Badry, K. Werner, K.J. Shen, J. Strader, A.C. Rodriguez, J.J. Han, V. Chandra, L. Chomiuk, Z.P. Vanderbosch, L. Blomberg, N. Yamaguchi, P. Nagarajan, I. Caiazzo, J.C. van Roestel, H. Glanz, T.L.S. Wong, A. Bhat, M.A. Hollands, The Open Journal of Astrophysics 9 (2026).","ieee":"K. El-Badry et al., “A systematic survey for hypervelocity runaways from thermonuclear supernovae,” The Open Journal of Astrophysics, vol. 9. Maynooth Academic Publishing, 2026."},"external_id":{"arxiv":["2606.11293"]},"acknowledgement":"We thank Lars Bildsten, Evan Bauer, Ruediger Pakmor, Jim Fuller, Logan Proust, Abinaya Rajamuthukumar, and Stephan Geier for useful discussion related to\r\nthis work.\r\nThis work was supported by NSF grants AST-2508988\r\nand AST-2205631, NASA/ESA Hubble Space Telescope\r\nprogram No. 17441, and Scialog grant #SA-LSST-2024-\r\n114c from the Research Corporation for Science Advancement. The Kavli Institute for Theoretical Physics\r\n(KITP) hosted the program, “White Dwarfs as Probes of\r\nthe Evolution of Planets, Stars, the Milky Way, and the\r\nExpanding Universe,” during which this project was initiated. This research was supported in part by the U.S.\r\nNational Science Foundation (NSF) under grants PHY1748958. This research benefited from discussions that\r\nwere funded by the Gordon and Betty Moore Foundation\r\nthrough Grant GBMF5076.\r\nWe thank the staffs of the various observatories at\r\nwhich data were obtained. This work is partially based\r\non observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project\r\nof the Minist´erio da Ciˆencia, Tecnologia e Inova¸c˜oes\r\n(MCTI/LNA) do Brasil, the US National Science Foundation’s NOIRLab, the University of North Carolina\r\nat Chapel Hill (UNC), and Michigan State University\r\n(MSU). Some of the data presented herein were obtained\r\nat the W. M. Keck Observatory, which is operated as a\r\nscientific partnership among the California Institute of\r\nTechnology, the University of California, and NASA; the observatory was made possible by the generous financial\r\nsupport of the W. M. Keck Foundation.\r\nThis research has made use of the Keck Observatory\r\nArchive (KOA), which is operated by the W. M. Keck\r\nObservatory and the NASA Exoplanet Science Institute\r\n(NExScI), under contract with the National Aeronautics\r\nand Space Administration.\r\nThis work has made use of data from the\r\nEuropean Space Agency (ESA) mission Gaia\r\n(https://www.cosmos.esa.int/gaia), processed\r\nby the Gaia Data Processing and Analysis Consortium\r\n(DPAC, https://www.cosmos.esa.int/web/gaia/\r\ndpac/consortium). Funding for the DPAC has been\r\nprovided by national institutions, in particular the\r\ninstitutions participating in the Gaia Multilateral\r\nAgreement.","volume":9,"supplementarymaterial":"no","date_updated":"2026-07-13T09:09:34Z","publication_status":"published","department":[{"_id":"IlCa"}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"file":[{"file_size":1994596,"creator":"dernst","date_created":"2026-07-13T09:05:36Z","access_level":"open_access","file_id":"22282","relation":"main_file","checksum":"6320fd19e5ea3399f332be5aab022736","date_updated":"2026-07-13T09:05:36Z","success":1,"content_type":"application/pdf","file_name":"2026_OpenJourAstrophysics_ElBadry.pdf"}],"article_type":"original","language":[{"iso":"eng"}],"date_created":"2026-07-12T22:02:19Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","arxiv":1,"quality_controlled":"1","intvolume":" 9","type":"journal_article","dataavailabilitystatement":"We thank the staffs of the various observatories at\r\nwhich data were obtained. This work is partially based\r\non observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project\r\nof the Minist´erio da Ciˆencia, Tecnologia e Inova¸c˜oes\r\n(MCTI/LNA) do Brasil, the US National Science Foundation’s NOIRLab, the University of North Carolina\r\nat Chapel Hill (UNC), and Michigan State University\r\n(MSU). Some of the data presented herein were obtained\r\nat the W. M. Keck Observatory, which is operated as a\r\nscientific partnership among the California Institute of\r\nTechnology, the University of California, and NASA; the\r\nobservatory was made possible by the generous financial\r\nsupport of the W. M. Keck Foundation.\r\nThis research has made use of the Keck Observatory\r\nArchive (KOA), which is operated by the W. M. Keck\r\nObservatory and the NASA Exoplanet Science Institute\r\n(NExScI), under contract with the National Aeronautics\r\nand Space Administration.\r\nThis work has made use of data from the\r\nEuropean Space Agency (ESA) mission Gaia\r\n(https://www.cosmos.esa.int/gaia), processed\r\nby the Gaia Data Processing and Analysis Consortium\r\n(DPAC, https://www.cosmos.esa.int/web/gaia/\r\ndpac/consortium). Funding for the DPAC has been\r\nprovided by national institutions, in particular the\r\ninstitutions participating in the Gaia Multilateral\r\nAgreement.","has_accepted_license":"1","date_published":"2026-06-30T00:00:00Z","researchdata_availability":"no","OA_type":"gold","keyword":["white dwarfs","binaries: close","stars: chemically peculiar"],"das_tickbox":"1","author":[{"last_name":"El-Badry","full_name":"El-Badry, Kareem","first_name":"Kareem"},{"last_name":"Werner","first_name":"Klaus","full_name":"Werner, Klaus"},{"first_name":"Ken J.","full_name":"Shen, Ken J.","last_name":"Shen"},{"first_name":"Jay","full_name":"Strader, Jay","last_name":"Strader"},{"last_name":"Rodriguez","full_name":"Rodriguez, Antonio C.","first_name":"Antonio C."},{"first_name":"Jiwon Jesse","full_name":"Han, Jiwon Jesse","last_name":"Han"},{"last_name":"Chandra","first_name":"Vedant","full_name":"Chandra, Vedant"},{"full_name":"Chomiuk, Laura","first_name":"Laura","last_name":"Chomiuk"},{"first_name":"Zachary P.","full_name":"Vanderbosch, Zachary P.","last_name":"Vanderbosch"},{"last_name":"Blomberg","full_name":"Blomberg, Lisa","first_name":"Lisa"},{"full_name":"Yamaguchi, Natsuko","first_name":"Natsuko","last_name":"Yamaguchi"},{"last_name":"Nagarajan","full_name":"Nagarajan, Pranav","first_name":"Pranav"},{"id":"8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d","full_name":"Caiazzo, Ilaria","orcid":"0000-0002-4770-5388","first_name":"Ilaria","last_name":"Caiazzo"},{"last_name":"van Roestel","first_name":"Joannes C","id":"4d122fc8-6083-11f0-87a5-97d68b860333","full_name":"van Roestel, Joannes C"},{"first_name":"Hila","full_name":"Glanz, Hila","last_name":"Glanz"},{"last_name":"Wong","first_name":"Tin Long Sunny","full_name":"Wong, Tin Long Sunny"},{"first_name":"Aakash","full_name":"Bhat, Aakash","last_name":"Bhat"},{"last_name":"Hollands","full_name":"Hollands, Mark A.","first_name":"Mark A."}],"abstract":[{"lang":"eng","text":"The explosion of a white dwarf (WD) in a close binary can launch a surviving runaway star at\r\nvelocities of ≳ 1000 km s−1\r\n. Such runaways provide a direct probe of thermonuclear supernovae (SNe)\r\nin double-degenerate binaries. Several candidate runaways are known, but their evolutionary states\r\nand the demographics of the broader population are uncertain. To enable robust population inference,\r\nwe carry out a systematic survey for hypervelocity runaways with a simple selection function, selecting\r\ncandidates based on large Gaia-inferred tangential velocities and blue colors. We classify 100% of the\r\nresulting 92 candidates using a combination of spectroscopic follow-up and archival data. The search\r\nyields ten suspected D6\r\nstars and three LP 40-365 stars. Three D6\r\nstars are new discoveries, including\r\ntwo hot (Teff ≳ 50,000 K) objects and one cool (Teff ≈ 7,000 K) object. We forward-model our survey\r\nunder several proposed D6\r\nstar evolutionary models, coupling each to a Galactic model and the survey\r\nselection function. No single model reproduces the observed diversity of D6\r\nstars, which likely reflects\r\na range of remnant masses, ages, and heating mechanisms. Models in which runaway companions\r\nare heated by SN shocks alone are too faint and short-lived to explain most of the observed sample,\r\nwhile fully reheated models are too luminous and long-lived. Models with intermediate heating,\r\nas occurs in some simulations of violent mergers and partially disrupted remnants, best match the\r\nobserved magnitude, distance, and kinematic-age distributions. The inferred D6\r\nstar birth rate is\r\nmodel dependent, but the models that best match the observed population require rates of only a\r\nfew percent of the Galactic SN Ia rate, perhaps implying that most SNe Ia result from WD binaries\r\nin which both components explode. If most SNe Ia do produce surviving runaways, these must be\r\nfainter or shorter-lived than the currently known runaways."}],"publication_identifier":{"eissn":["2565-6120"]},"day":"30","PlanS_conform":"1","fulldoi":"https://doi.org/10.33232/001c.164326","ddc":["520"],"doi":"10.33232/001c.164326","file_date_updated":"2026-07-13T09:05:36Z","OA_place":"publisher","publisher":"Maynooth Academic Publishing","article_processing_charge":"No","oa":1,"scopus_import":"1","title":"A systematic survey for hypervelocity runaways from thermonuclear supernovae","DOAJ_listed":"1","publication":"The Open Journal of Astrophysics","status":"public","_id":"22270","month":"06","year":"2026"},{"publication_status":"epub_ahead","department":[{"_id":"MaLo"},{"_id":"GradSch"}],"date_updated":"2026-07-13T09:22:49Z","supplementarymaterial":"yes","article_type":"original","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"quality_controlled":"1","oa_version":"Published Version","date_created":"2026-07-12T22:02:19Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"researchdata_availability":"yes","date_published":"2026-07-03T00:00:00Z","has_accepted_license":"1","dataavailabilitystatement":"The data, plasmids and strains that support the findings of this study are available from the corresponding authors by request. Representative tomograms are deposited in EMDB: EMD-27479 (wild-type), EMD-53351 (∆ponB), EMD-53357(∆lpoB) and EMD-53363 (∆ponA). Corresponding raw movie frames and stacks of tilt series are deposited as EMPIAR-11090 (wild type), EMPIAR-13502 (∆ponB), EMPIAR-13513 (∆lpoB) and EMPIAR-13512 (∆ponA), and will be released upon publication. Other data related to this manuscript (for example, AFM, light microscopy, growth curves and so on) can be found on Zenodo at https://doi.org/10.5281/zenodo.20841819 (ref. 101). Source data are provided with this paper. Scripts used in this study were deposited on GitHub at https://github.com/NavarroVettiger/Navarro-et-al_2022 and https://github.com/virlyananda/EM-ImageProcessing.","type":"journal_article","main_file_link":[{"url":"https://doi.org/10.1038/s41564-026-02403-6","open_access":"1"}],"external_id":{"pmid":["42399561"]},"citation":{"ieee":"P. P. Navarro et al., “The penicillin-binding protein PBP1b fortifies the Escherichia coli division site against osmotic rupture,” Nature Microbiology. Springer Nature, 2026.","short":"P.P. Navarro, A. Vettiger, R. Hajdu, V.Y. Ananda, A. López-Tavares, E.W. Schmid, J.C. Walter, M. Loose, L.H. Chao, T.G. Bernhardt, Nature Microbiology (2026).","ista":"Navarro PP, Vettiger A, Hajdu R, Ananda VY, López-Tavares A, Schmid EW, Walter JC, Loose M, Chao LH, Bernhardt TG. 2026. The penicillin-binding protein PBP1b fortifies the Escherichia coli division site against osmotic rupture. Nature Microbiology.","ama":"Navarro PP, Vettiger A, Hajdu R, et al. The penicillin-binding protein PBP1b fortifies the Escherichia coli division site against osmotic rupture. Nature Microbiology. 2026. doi:10.1038/s41564-026-02403-6","mla":"Navarro, Paula P., et al. “The Penicillin-Binding Protein PBP1b Fortifies the Escherichia Coli Division Site against Osmotic Rupture.” Nature Microbiology, Springer Nature, 2026, doi:10.1038/s41564-026-02403-6.","apa":"Navarro, P. P., Vettiger, A., Hajdu, R., Ananda, V. Y., López-Tavares, A., Schmid, E. W., … Bernhardt, T. G. (2026). The penicillin-binding protein PBP1b fortifies the Escherichia coli division site against osmotic rupture. Nature Microbiology. Springer Nature. https://doi.org/10.1038/s41564-026-02403-6","chicago":"Navarro, Paula P., Andrea Vettiger, Roman Hajdu, Virly Y. Ananda, Alejandro López-Tavares, Ernst W. Schmid, Johannes C. Walter, Martin Loose, Luke H. Chao, and Thomas G. Bernhardt. “The Penicillin-Binding Protein PBP1b Fortifies the Escherichia Coli Division Site against Osmotic Rupture.” Nature Microbiology. Springer Nature, 2026. https://doi.org/10.1038/s41564-026-02403-6."},"acknowledgement":"We thank all members of the Bernhardt, Rudner, Navarro and Vettiger Laboratories for support and helpful conversations. We thank C. Genoud, J. Daraspe, A. Mucciolo and D. de Bellis at the Electron Microscopy Facility of the University of Lausanne and E. Jeanvoine for providing access to workstations for cryo-ET image processing; S. Sterling, C. Borsa, J. Podgorski, P. Vinh Dip, E. Brignole and A. Osherov at the MIT.nano cryo-EM facility, K. Song and C. Xu at the University of Massachusetts cryo-EM facility, and R. Walsh and Z. Li at the cryo-EM at Harvard Medical School facility for providing access to the cryo-EM microscopes and for all their help, advice and maintenance of cryo-EM equipment. AFM was performed at the Harvard University Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under NSF award no. ECCS-2025158. We thank N. S. Colella for excellent advice on AFM data acquisition and analysis; the MicRoN imaging core at Harvard Medical School for excellent advice on live cell imaging and maintenance of fluorescence microscopes; B. Krautz for creating the cartoon illustrations (www.sciencecommunicated.com); and L. Miles and R. Aeschimann for assistance with strain construction. A.V. was supported by an EMBO long-term postdoctoral fellowship ALTF_89-2019, the Swiss National Science Foundation (SNSF) Postdoc.Mobility fellowship P500PB_203143. P.P.N. was a recipient of early postdoc.mobility and postdoc.mobility fellowships (P2BSP3_188112 and P400PB_199252). This work was also supported by funding from the National Institutes of Health (R35GM142553 to L.H.C. and R01AI083365 to T.G.B.), investigator funds from the Howard Hughes Medical Institute (T.G.B.), an SNSF project grant (320030-236243 to A.V.), an SNSF Starting Grant (TMSGI3_218251 to P.P.N.), an SNSF Project grant (320030-236069 to P.P.N), an SNSF SPARK grant (CRSK-3_237167 to P.P.N.), cryo-EM funds from the Faculty of Biology and Medicine at University of Lausanne to P.P.N. and the Foundation Pierre Mercier pour la Science (to P.P.N.).","day":"03","publication_identifier":{"eissn":["2058-5276"]},"publisher":"Springer Nature","OA_place":"publisher","doi":"10.1038/s41564-026-02403-6","fulldoi":"https://doi.org/10.1038/s41564-026-02403-6","ddc":["570"],"title":"The penicillin-binding protein PBP1b fortifies the Escherichia coli division site against osmotic rupture","scopus_import":"1","oa":1,"article_processing_charge":"Yes (in subscription journal)","year":"2026","_id":"22269","status":"public","month":"07","publication":"Nature Microbiology","das_tickbox":"1","OA_type":"hybrid","author":[{"last_name":"Navarro","full_name":"Navarro, Paula P.","first_name":"Paula P."},{"last_name":"Vettiger","first_name":"Andrea","full_name":"Vettiger, Andrea"},{"id":"ffab949d-133f-11ed-8f02-94de21ace503","full_name":"Hajdu, Roman","first_name":"Roman","last_name":"Hajdu"},{"full_name":"Ananda, Virly Y.","first_name":"Virly Y.","last_name":"Ananda"},{"last_name":"López-Tavares","full_name":"López-Tavares, Alejandro","first_name":"Alejandro"},{"first_name":"Ernst W.","full_name":"Schmid, Ernst W.","last_name":"Schmid"},{"first_name":"Johannes C.","full_name":"Walter, Johannes C.","last_name":"Walter"},{"last_name":"Loose","orcid":"0000-0001-7309-9724","first_name":"Martin","full_name":"Loose, Martin","id":"462D4284-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Chao","first_name":"Luke H.","full_name":"Chao, Luke H."},{"last_name":"Bernhardt","first_name":"Thomas G.","full_name":"Bernhardt, Thomas G."}],"pmid":1,"abstract":[{"text":"The divisome apparatus synthesizes septal peptidoglycan (PG) during bacterial division. In Escherichia coli, the class A penicillin-binding protein (aPBP) called PBP1b has been implicated in division, but its role in the process has remained unclear. Here we show using in situ cryo-electron tomography, genetics and other imaging methods that PBP1b is required to produce a wedge-like density of PG at the division site and that loss of this structure weakens the division site, making it hypersusceptible to osmotic lysis. Surprisingly, the activator LpoB needed for general PBP1b function was not required for its role in division. Of the two PBP1b isoforms produced in cells, we show that the one with an extended cytoplasmic N terminus localizes to and functions at the division site, probably via recruitment by the FtsA component of the divisome. The conservation of aPBPs with extended cytoplasmic N termini suggests that other Gram-negative bacteria may use similar mechanisms for division site reinforcement.","lang":"eng"}]},{"acknowledgement":"The authors thank Katharine Jensen, Stefanie Heyden, Thomas Salez, Francesco Stellacci, Denis Bartolo, Francesco Picella, Hélène Delanoë-Ayari, Mathieu Leocmach, Antoine Bérut, Cécile Cottin-Bizonne, Anne-Laure Biance, and Oriane Talabart for useful discussions. We also thank the reviewers for excellent suggestions that substantively improved the manuscript.","volume":16,"external_id":{"arxiv":["2410.09158"]},"citation":{"chicago":"Bain, Nicolas, Lawrence A. Wilen, Dominic Gerber, Mengjie Zu, Carl Peter Goodrich, Senthilkumar Duraivel, Kaarthik Varma, Harsha Koganti, Robert W. Style, and Eric R. Dufresne. “Multiscale Interfacial Mechanics of Soft Solids.” Physical Review X. American Physical Society, 2026. https://doi.org/10.1103/8msx-l8s7.","ieee":"N. Bain et al., “Multiscale interfacial mechanics of soft solids,” Physical Review X, vol. 16, no. 2. American Physical Society, 2026.","short":"N. Bain, L.A. Wilen, D. Gerber, M. Zu, C.P. Goodrich, S. Duraivel, K. Varma, H. Koganti, R.W. Style, E.R. Dufresne, Physical Review X 16 (2026).","ista":"Bain N, Wilen LA, Gerber D, Zu M, Goodrich CP, Duraivel S, Varma K, Koganti H, Style RW, Dufresne ER. 2026. Multiscale interfacial mechanics of soft solids. Physical Review X. 16(2), 021063.","ama":"Bain N, Wilen LA, Gerber D, et al. Multiscale interfacial mechanics of soft solids. Physical Review X. 2026;16(2). doi:10.1103/8msx-l8s7","mla":"Bain, Nicolas, et al. “Multiscale Interfacial Mechanics of Soft Solids.” Physical Review X, vol. 16, no. 2, 021063, American Physical Society, 2026, doi:10.1103/8msx-l8s7.","apa":"Bain, N., Wilen, L. A., Gerber, D., Zu, M., Goodrich, C. P., Duraivel, S., … Dufresne, E. R. (2026). Multiscale interfacial mechanics of soft solids. Physical Review X. American Physical Society. https://doi.org/10.1103/8msx-l8s7"},"issue":"2","has_accepted_license":"1","type":"journal_article","dataavailabilitystatement":"The data that support the findings of this article are openly available https://github.com/nicobain/Multiscale_interfacial_mechanics_soft_solids_data","date_published":"2026-06-30T00:00:00Z","researchdata_availability":"yes","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","date_created":"2026-07-13T09:40:54Z","language":[{"iso":"eng"}],"quality_controlled":"1","intvolume":" 16","arxiv":1,"file":[{"file_id":"22309","relation":"main_file","checksum":"47354f40981223fb0c9afe292f16ead1","date_updated":"2026-07-13T11:16:47Z","success":1,"content_type":"application/pdf","file_name":"2026_PhysicalReviewX_Bain.pdf","file_size":4367284,"creator":"dernst","date_created":"2026-07-13T11:16:47Z","access_level":"open_access"}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","date_updated":"2026-07-13T11:17:51Z","supplementarymaterial":"yes","publication_status":"published","department":[{"_id":"CaGo"}],"abstract":[{"text":"Soft solids and their surface deformations control the response of many natural and artificial systems. Yet, their underlying properties are vigorously debated, particularly for polymer networks. While molecular-scale theories predict no interfacial changes with macroscopic deformation, multiple experiments suggest otherwise. To settle this issue, we measure displacement fields near the interface of a silicone gel, in the limit of small deformations. We discover an unexpected multiscale response. The shear modulus decreases smoothly by half with 20 μm of the interface. At the same time we observe a surface excess elasticity, that depends on history and outer medium composition. These results reveal the fundamentally multiscale nature of polymeric surfaces, and call for further experimental and theoretical investigations into the basic understanding of soft solid interfaces.","lang":"eng"}],"author":[{"last_name":"Bain","first_name":"Nicolas","full_name":"Bain, Nicolas"},{"first_name":"Lawrence A.","full_name":"Wilen, Lawrence A.","last_name":"Wilen"},{"last_name":"Gerber","full_name":"Gerber, Dominic","first_name":"Dominic"},{"last_name":"Zu","first_name":"Mengjie","id":"26dd9e7c-e86a-11eb-a854-82ac731c9ae2","full_name":"Zu, Mengjie"},{"first_name":"Carl Peter","orcid":"0000-0002-1307-5074","id":"EB352CD2-F68A-11E9-89C5-A432E6697425","full_name":"Goodrich, Carl Peter","last_name":"Goodrich"},{"first_name":"Senthilkumar","full_name":"Duraivel, Senthilkumar","last_name":"Duraivel"},{"first_name":"Kaarthik","full_name":"Varma, Kaarthik","last_name":"Varma"},{"last_name":"Koganti","first_name":"Harsha","full_name":"Koganti, Harsha"},{"first_name":"Robert W.","full_name":"Style, Robert W.","last_name":"Style"},{"full_name":"Dufresne, Eric R.","first_name":"Eric R.","last_name":"Dufresne"}],"OA_type":"gold","article_number":"021063","das_tickbox":"1","publication":"Physical Review X","DOAJ_listed":"1","year":"2026","_id":"22288","status":"public","month":"06","oa":1,"article_processing_charge":"Yes","title":"Multiscale interfacial mechanics of soft solids","scopus_import":"1","ddc":["530"],"fulldoi":"https://doi.org/10.1103/8msx-l8s7","publisher":"American Physical Society","OA_place":"publisher","file_date_updated":"2026-07-13T11:16:47Z","doi":"10.1103/8msx-l8s7","publication_identifier":{"issn":["2160-3308"]},"PlanS_conform":"1","day":"30"},{"language":[{"iso":"eng"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_created":"2026-07-13T09:39:40Z","oa_version":"None","intvolume":" 36","quality_controlled":"1","type":"journal_article","date_published":"2026-07-06T00:00:00Z","researchdata_availability":"no","supplementarymaterial":"no","date_updated":"2026-07-13T11:11:56Z","publication_status":"published","department":[{"_id":"EvBe"},{"_id":"GradSch"}],"article_type":"original","volume":36,"issue":"13","citation":{"chicago":"Leitner, Valentin, and Eva Benková. “Auxin and the Control of Plant Growth and Development.” Current Biology. Elsevier, 2026. https://doi.org/10.1016/j.cub.2026.04.047.","short":"V. Leitner, E. Benková, Current Biology 36 (2026) R739–R744.","ieee":"V. Leitner and E. Benková, “Auxin and the control of plant growth and development,” Current Biology, vol. 36, no. 13. Elsevier, pp. R739–R744, 2026.","apa":"Leitner, V., & Benková, E. (2026). Auxin and the control of plant growth and development. Current Biology. Elsevier. https://doi.org/10.1016/j.cub.2026.04.047","mla":"Leitner, Valentin, and Eva Benková. “Auxin and the Control of Plant Growth and Development.” Current Biology, vol. 36, no. 13, Elsevier, 2026, pp. R739–44, doi:10.1016/j.cub.2026.04.047.","ista":"Leitner V, Benková E. 2026. Auxin and the control of plant growth and development. Current Biology. 36(13), R739–R744.","ama":"Leitner V, Benková E. Auxin and the control of plant growth and development. Current Biology. 2026;36(13):R739-R744. doi:10.1016/j.cub.2026.04.047"},"page":"R739-R744","external_id":{"pmid":["42407441"]},"article_processing_charge":"No","scopus_import":"1","title":"Auxin and the control of plant growth and development","publication":"Current Biology","status":"public","_id":"22286","month":"07","year":"2026","publication_identifier":{"issn":["0960-9822"]},"day":"06","fulldoi":"https://doi.org/10.1016/j.cub.2026.04.047","doi":"10.1016/j.cub.2026.04.047","publisher":"Elsevier","pmid":1,"author":[{"last_name":"Leitner","full_name":"Leitner, Valentin","id":"4c665ce3-0016-11ec-bea0-e44de7a4fa3d","first_name":"Valentin"},{"last_name":"Benková","first_name":"Eva","orcid":"0000-0002-8510-9739","id":"38F4F166-F248-11E8-B48F-1D18A9856A87","full_name":"Benková, Eva"}],"abstract":[{"text":"Plants are remarkable organisms. Unlike animals, they cannot flee and, rooted in one place, they must cope with whatever challenges arise — nutrient scarcity, drought, shade, wind or obstacles in the soil. Their extraordinary ability to survive in such unstable environmental conditions lies in their capacity to adapt. In response to environmental signals, plants can rapidly adjust the rate of organ growth, change the direction of growth, bend toward resources, or remodel their body architecture by promoting or suppressing the formation of new organs such as lateral roots, branches, leaves, or flowers. This unique developmental plasticity depends on chemical signals, plant hormones that serve as regulators and coordinators of endogenous molecular and cellular processes. Chief among these signals is auxin, a plant hormone central to nearly every aspect of plant life.","lang":"eng"}],"OA_type":"closed access","das_tickbox":"0","corr_author":"1"},{"scopus_import":"1","title":"Additive partial matchings induced by persistence maps","article_processing_charge":"No","oa":1,"month":"06","_id":"22291","status":"public","year":"2026","publication":"Journal of Symbolic Computation","day":"23","PlanS_conform":"1","publication_identifier":{"issn":["0747-7171"],"eissn":["1095-855X"]},"OA_place":"publisher","doi":"10.1016/j.jsc.2026.102598","publisher":"Elsevier","ddc":["500"],"fulldoi":"https://doi.org/10.1016/j.jsc.2026.102598","author":[{"first_name":"Rocio","full_name":"Gonzalez-Diaz, Rocio","last_name":"Gonzalez-Diaz"},{"full_name":"Soriano Trigueros, Manuel","id":"15ebd7cf-15bf-11ee-aebd-bb4bb5121ea8","first_name":"Manuel","orcid":"0000-0003-2449-1433","last_name":"Soriano Trigueros"},{"last_name":"Torras-Casas","first_name":"Alvaro","full_name":"Torras-Casas, Alvaro"}],"abstract":[{"lang":"eng","text":"Persistent homology is a fundamental tool in Topological Data Analysis. The associated algebraic structure is the persistence module, a sequence of vector spaces connected by linear maps. Persistence modules admit a complete and fast-to-compute invariant known as the persistence diagram. However, this is no longer the case for maps between persistence modules (i.e. persistence maps). We propose a new invariant for persistence maps, consisting of a partial matching between the persistence diagrams of the domain and codomain modules. We show that this invariant is additive with respect to the direct sum decomposition of persistence maps, is more discriminative than the image module, and is computable in cubic time. Furthermore, we provide an implementation and demonstrate its efficiency by integrating it with edge collapse techniques for flag complexes (e.g., Vietoris–Rips complexes). As a key technical contribution, we describe how to induce a persistence map between two flag complexes that have been independently simplified via edge collapses, even when a direct simplicial map between them is no longer available."}],"das_tickbox":"1","corr_author":"1","article_number":"102598","keyword":["Persistence module","Persistence map","Persistent homology"],"OA_type":"hybrid","intvolume":" 138","arxiv":1,"quality_controlled":"1","language":[{"iso":"eng"}],"oa_version":"Published Version","date_created":"2026-07-13T09:43:38Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_published":"2026-06-23T00:00:00Z","researchdata_availability":"yes","type":"journal_article","dataavailabilitystatement":"The code used for the computational experiments is available in https://github.com/Cimagroup/IBloFunMatch","has_accepted_license":"1","publication_status":"epub_ahead","department":[{"_id":"HeEd"}],"supplementarymaterial":"no","date_updated":"2026-07-13T12:00:07Z","mathsc":["55N31","16G20"],"article_type":"original","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"acknowledgement":"This project was partially funded by MCIN/AEI and the NextGenerationEU/PRTR, under project TED2021-129438B-I00. The authors thank IMUS-Maria de Maeztu grant CEX2024-001517-M - Apoyo a Unidades de Excelencia María de Maeztu for supporting this research, funded by MICIU/AEI/ 10.13039/501100011033. The authors would also like to thank Lars M Salbu for fruitful discussions regarding the operators from Definition 4.1 and their relation with the order relations introduced in Definition 3.2.","volume":138,"main_file_link":[{"url":"https://doi.org/10.1016/j.jsc.2026.102598","open_access":"1"}],"citation":{"chicago":"Gonzalez-Diaz, Rocio, Manuel Soriano Trigueros, and Alvaro Torras-Casas. “Additive Partial Matchings Induced by Persistence Maps.” Journal of Symbolic Computation. Elsevier, 2026. https://doi.org/10.1016/j.jsc.2026.102598.","apa":"Gonzalez-Diaz, R., Soriano Trigueros, M., & Torras-Casas, A. (2026). Additive partial matchings induced by persistence maps. Journal of Symbolic Computation. Elsevier. https://doi.org/10.1016/j.jsc.2026.102598","mla":"Gonzalez-Diaz, Rocio, et al. “Additive Partial Matchings Induced by Persistence Maps.” Journal of Symbolic Computation, vol. 138, 102598, Elsevier, 2026, doi:10.1016/j.jsc.2026.102598.","ama":"Gonzalez-Diaz R, Soriano Trigueros M, Torras-Casas A. Additive partial matchings induced by persistence maps. Journal of Symbolic Computation. 2026;138. doi:10.1016/j.jsc.2026.102598","ista":"Gonzalez-Diaz R, Soriano Trigueros M, Torras-Casas A. 2026. Additive partial matchings induced by persistence maps. Journal of Symbolic Computation. 138, 102598.","short":"R. Gonzalez-Diaz, M. Soriano Trigueros, A. Torras-Casas, Journal of Symbolic Computation 138 (2026).","ieee":"R. Gonzalez-Diaz, M. Soriano Trigueros, and A. Torras-Casas, “Additive partial matchings induced by persistence maps,” Journal of Symbolic Computation, vol. 138. Elsevier, 2026."},"external_id":{"arxiv":["2006.11100"]}},{"article_processing_charge":"Yes","title":"Tailoring the major groove of DNA mimic foldamers","scopus_import":"1","DOAJ_listed":"1","publication":"Chemical Science","year":"2026","_id":"22289","status":"public","month":"06","publication_identifier":{"issn":["2041-6520"],"eissn":["2041-6539"]},"day":"09","ddc":["540"],"fulldoi":"https://doi.org/10.1039/d6sc00798h","publisher":"Royal Society of Chemistry","OA_place":"publisher","doi":"10.1039/d6sc00798h","author":[{"first_name":"Jiaojiao","full_name":"Wu, Jiaojiao","last_name":"Wu"},{"first_name":"Valentina","full_name":"Corvaglia, Valentina","last_name":"Corvaglia"},{"first_name":"Tulika","full_name":"Chakrabortty, Tulika","last_name":"Chakrabortty"},{"last_name":"Mandal","full_name":"Mandal, Pradeep K","id":"6a3def15-d4b4-11ef-9fa9-a24c1f545ec3","first_name":"Pradeep K","orcid":"0000-0001-5996-956X"},{"last_name":"Huc","full_name":"Huc, Ivan","first_name":"Ivan"}],"abstract":[{"lang":"eng","text":"Single-stranded, helically folded aromatic oligoamides bearing anionic phosphonate side chains have been shown to bind to some DNA-binding proteins better than DNA itself. However, these DNA mimic foldamers have until now mainly consisted of a single repeat motif, like a poly(dA:dT) DNA duplex, and contained limited sequence information. Here, we introduce new monomers designed to display different chemical functionalities in the major groove of the DNA mimics. Four new Fmoc-protected amino acid monomers have been synthesized and incorporated into oligomers. Sixteen foldamer sequences were prepared on solid phase. Their conformations in solution and in the solid state and their conformational dynamics were investigated using nuclear magnetic resonance, circular dichroism, molecular modeling, and X-ray crystallography. The results show that three of the four new monomers behaved as designed and that their introduction enhances the conformational dynamics of the DNA mimic foldamers. In a fourth case, conformational behavior proved to be more complex than expected. The modified sequences retained the ability to bind to the bacterial histone-like protein HU. These results showcase design strategies to manipulate large molecular biomimetics in which not only side chains but also main chain components are varied. The new monomers pave the way to complex DNA mimic foldamer sequences targeting proteins that recognize sequence-selective DNA-binding proteins such as transcription factors or restriction enzymes."}],"OA_type":"gold","das_tickbox":"1","oa_version":"Published Version","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_created":"2026-07-13T09:41:36Z","language":[{"iso":"eng"}],"quality_controlled":"1","has_accepted_license":"1","type":"journal_article","dataavailabilitystatement":"CCDC 2514117, 2514118, 2286782 and 2478322 (compound 1, compound 1d, oligomer 5, and oligomer 6, respectively) contain the supplementary crystallographic data for this paper.54a–d \r\n\r\nThe supporting data have been provided as part of the supplementary information (SI). Supplementary information: SI figures, detailed experimental protocols, crystallographic studies, and characterisation of new compounds. See DOI: https://doi.org/10.1039/d6sc00798h.","researchdata_availability":"yes","date_published":"2026-06-09T00:00:00Z","date_updated":"2026-07-13T11:24:29Z","supplementarymaterial":"yes","department":[{"_id":"LifeSc"}],"publication_status":"inpress","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","acknowledgement":"We acknowledge financial support from the European Research Council (ERC) under the European Union's Horizon Europe Framework Programme (grant agreement no. ERC-2021-ADG-320892) and from the China Scholarship Council (CSC, predoctoral fellowship to J. W.). We thank L. Allmendinger for assistance with NMR measurements, P. Mayer for his assistance in solving the crystal structures of 1 and 1d, L. Bodero for assistance with automated solid-phase synthesis, M. Rogovoi for providing monomer precursors, and M. Loos for the purification and analysis of compounds 15a–19a. We thank M. Soler-Lopez (ID23-1, ESRF, Grenoble) and I. Bento (EMBL P13, Petra III, DESY, Hamburg) for assistance during data collection at the synchrotron beamlines.","citation":{"ista":"Wu J, Corvaglia V, Chakrabortty T, Mandal PK, Huc I. Tailoring the major groove of DNA mimic foldamers. Chemical Science.","ama":"Wu J, Corvaglia V, Chakrabortty T, Mandal PK, Huc I. Tailoring the major groove of DNA mimic foldamers. Chemical Science. doi:10.1039/d6sc00798h","mla":"Wu, Jiaojiao, et al. “Tailoring the Major Groove of DNA Mimic Foldamers.” Chemical Science, Royal Society of Chemistry, doi:10.1039/d6sc00798h.","apa":"Wu, J., Corvaglia, V., Chakrabortty, T., Mandal, P. K., & Huc, I. (n.d.). Tailoring the major groove of DNA mimic foldamers. Chemical Science. Royal Society of Chemistry. https://doi.org/10.1039/d6sc00798h","ieee":"J. Wu, V. Corvaglia, T. Chakrabortty, P. K. Mandal, and I. Huc, “Tailoring the major groove of DNA mimic foldamers,” Chemical Science. Royal Society of Chemistry.","short":"J. Wu, V. Corvaglia, T. Chakrabortty, P.K. Mandal, I. Huc, Chemical Science (n.d.).","chicago":"Wu, Jiaojiao, Valentina Corvaglia, Tulika Chakrabortty, Pradeep K Mandal, and Ivan Huc. “Tailoring the Major Groove of DNA Mimic Foldamers.” Chemical Science. Royal Society of Chemistry, n.d. https://doi.org/10.1039/d6sc00798h."}},{"abstract":[{"text":"We introduce a multi-band BCS free energy functional and prove that for a multi-band superconductor the effect of inter-band coupling can only increase the critical temperature, irrespective of its attractive or repulsive nature and its strength. Further, for weak coupling and weaker inter-band coupling, we prove that the dependence of the increase in critical temperature on the inter-band coupling is (1) linear, if there are two or more equally strongly superconducting bands, or (2) quadratic, if there is only one dominating band.","lang":"eng"}],"related_material":{"record":[{"id":"19550","relation":"earlier_version","status":"public"}]},"author":[{"id":"31d731d7-d235-11ea-ad11-b50331c8d7fb","full_name":"Henheik, Sven Joscha","first_name":"Sven Joscha","orcid":"0000-0003-1106-327X","last_name":"Henheik"},{"full_name":"Langmann, Edwin","first_name":"Edwin","last_name":"Langmann"},{"first_name":"Asbjørn Bækgaard","orcid":"0000-0003-4476-2288","id":"e1a2682f-dc8d-11ea-abe3-81da9ac728f1","full_name":"Lauritsen, Asbjørn Bækgaard","last_name":"Lauritsen"}],"OA_type":"hybrid","das_tickbox":"1","publication":"Annales Henri Poincaré","year":"2026","_id":"22290","status":"public","month":"06","oa":1,"article_processing_charge":"Yes (via OA deal)","title":"Multi-band superconductors have enhanced critical temperatures","scopus_import":"1","ddc":["500"],"fulldoi":"https://doi.org/10.1007/s00023-026-01706-y","publisher":"Springer Nature","doi":"10.1007/s00023-026-01706-y","OA_place":"publisher","publication_identifier":{"eissn":["1424-0661"],"issn":["1424-0637"]},"PlanS_conform":"1","day":"29","acknowledgement":"We would like to thank J. Lenells and R. Seiringer for their interest and helpful discussions, E. Babaev and Y. Yerin for useful comments about the literature, and the anonymous referee for their comments. J.H. gratefully acknowledges partial financial support by the ERC Advanced Grant “RMTBeyond” No. 101020331 and the ERC Consollidator Grant “ProbQuant” (jointly with the Swiss State Secretariat for Education, Research and Innovation). E.L. gratefully acknowledges support from the Swedish Research Council, Grant No. 2023-04726. A.B.L. gratefully acknowledges partial financial support by the Austrian Science Fund (FWF) through grant DOI: 10.55776/I6427 (as part of the SFB/TRR 352) and by the French State support managed by ANR under the France 2030 program through the MaQuI CNRS Risky and High-Impact Research programme (RI)^2 (grant agreement ANR-24-RRII-0001). Open access funding provided by Royal Institute of Technology.","project":[{"_id":"62796744-2b32-11ec-9570-940b20777f1d","name":"Random matrices beyond Wigner-Dyson-Mehta","grant_number":"101020331","call_identifier":"H2020"},{"grant_number":"I06427","name":"Mathematical Challenges in BCS Theory of Superconductivity","_id":"bda63fe5-d553-11ed-ba76-a16e3d2f256b"}],"external_id":{"arxiv":["2409.17297"]},"citation":{"chicago":"Henheik, Sven Joscha, Edwin Langmann, and Asbjørn Bækgaard Lauritsen. “Multi-Band Superconductors Have Enhanced Critical Temperatures.” Annales Henri Poincaré. Springer Nature, 2026. https://doi.org/10.1007/s00023-026-01706-y.","apa":"Henheik, S. J., Langmann, E., & Lauritsen, A. B. (2026). Multi-band superconductors have enhanced critical temperatures. Annales Henri Poincaré. Springer Nature. https://doi.org/10.1007/s00023-026-01706-y","mla":"Henheik, Sven Joscha, et al. “Multi-Band Superconductors Have Enhanced Critical Temperatures.” Annales Henri Poincaré, Springer Nature, 2026, doi:10.1007/s00023-026-01706-y.","ama":"Henheik SJ, Langmann E, Lauritsen AB. Multi-band superconductors have enhanced critical temperatures. Annales Henri Poincaré. 2026. doi:10.1007/s00023-026-01706-y","ista":"Henheik SJ, Langmann E, Lauritsen AB. 2026. Multi-band superconductors have enhanced critical temperatures. Annales Henri Poincaré.","short":"S.J. Henheik, E. Langmann, A.B. Lauritsen, Annales Henri Poincaré (2026).","ieee":"S. J. Henheik, E. Langmann, and A. B. Lauritsen, “Multi-band superconductors have enhanced critical temperatures,” Annales Henri Poincaré. Springer Nature, 2026."},"main_file_link":[{"open_access":"1","url":"https://doi.org/10.1007/s00023-026-01706-y"}],"ec_funded":1,"has_accepted_license":"1","dataavailabilitystatement":"Data sharing is not applicable to this article as no new data were created or analyzed in this study.","type":"journal_article","researchdata_availability":"not applicable","date_published":"2026-06-29T00:00:00Z","oa_version":"Published Version","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_created":"2026-07-13T09:42:22Z","language":[{"iso":"eng"}],"quality_controlled":"1","arxiv":1,"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"article_type":"original","date_updated":"2026-07-13T11:34:08Z","supplementarymaterial":"not applicable","publication_status":"epub_ahead","department":[{"_id":"LaEr"},{"_id":"RoSe"}]},{"OA_type":"green","article_number":"061901","corr_author":"1","das_tickbox":"1","abstract":[{"lang":"eng","text":"We show that a suitable choice of boundary conditions for the Laplacian allows for the appearance of an arbitrary number of condensates, described by arbitrary harmonic functions, in the thermodynamic limit of an ideal Bose gas."}],"author":[{"last_name":"De Wilde","id":"bebf1407-6635-11f0-9fef-9b7e2dd151d0","full_name":"De Wilde, Michiel","first_name":"Michiel"},{"last_name":"Seiringer","full_name":"Seiringer, Robert","id":"4AFD0470-F248-11E8-B48F-1D18A9856A87","first_name":"Robert","orcid":"0000-0002-6781-0521"}],"fulldoi":"https://doi.org/10.1063/5.0325354","publisher":"AIP Publishing","OA_place":"repository","doi":"10.1063/5.0325354","publication_identifier":{"eissn":["1089-7658"],"issn":["0022-2488"]},"day":"01","publication":"Journal of Mathematical Physics","year":"2026","_id":"22292","month":"06","status":"public","oa":1,"article_processing_charge":"No","title":"Arbitrary harmonic functions as Bose–Einstein condensates","scopus_import":"1","external_id":{"arxiv":["2601.22883"]},"citation":{"short":"M. De Wilde, R. Seiringer, Journal of Mathematical Physics 67 (2026).","ieee":"M. De Wilde and R. Seiringer, “Arbitrary harmonic functions as Bose–Einstein condensates,” Journal of Mathematical Physics, vol. 67, no. 6. AIP Publishing, 2026.","apa":"De Wilde, M., & Seiringer, R. (2026). Arbitrary harmonic functions as Bose–Einstein condensates. Journal of Mathematical Physics. AIP Publishing. https://doi.org/10.1063/5.0325354","mla":"De Wilde, Michiel, and Robert Seiringer. “Arbitrary Harmonic Functions as Bose–Einstein Condensates.” Journal of Mathematical Physics, vol. 67, no. 6, 061901, AIP Publishing, 2026, doi:10.1063/5.0325354.","ista":"De Wilde M, Seiringer R. 2026. Arbitrary harmonic functions as Bose–Einstein condensates. Journal of Mathematical Physics. 67(6), 061901.","ama":"De Wilde M, Seiringer R. Arbitrary harmonic functions as Bose–Einstein condensates. Journal of Mathematical Physics. 2026;67(6). doi:10.1063/5.0325354","chicago":"De Wilde, Michiel, and Robert Seiringer. “Arbitrary Harmonic Functions as Bose–Einstein Condensates.” Journal of Mathematical Physics. AIP Publishing, 2026. https://doi.org/10.1063/5.0325354."},"main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2601.22883"}],"issue":"6","volume":67,"acknowledgement":"We are grateful to Rupert Frank and Jakob Yngvason for helpful discussions and suggestions.","article_type":"original","date_updated":"2026-07-13T12:20:59Z","supplementarymaterial":"not applicable","publication_status":"published","department":[{"_id":"RoSe"},{"_id":"GradSch"}],"type":"journal_article","dataavailabilitystatement":"Data sharing is not applicable to this article as no new data were created or analyzed in this study.","researchdata_availability":"not applicable","date_published":"2026-06-01T00:00:00Z","date_created":"2026-07-13T09:45:09Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Preprint","language":[{"iso":"eng"}],"arxiv":1,"intvolume":" 67","quality_controlled":"1"},{"article_processing_charge":"No","scopus_import":"1","title":"Pollination and Fertilization","publication":"Regulation of Plant Development","month":"04","status":"public","_id":"22293","year":"2026","publication_identifier":{"eisbn":["9789819570331"],"isbn":["9789819570324"]},"day":"24","fulldoi":"https://doi.org/10.1007/978-981-95-7033-1_14","doi":"10.1007/978-981-95-7033-1_14","publisher":"Springer Nature","editor":[{"last_name":"Chang","full_name":"Chang, Fang ","first_name":"Fang "},{"last_name":"Wang","full_name":"Wang, Yingxiang","first_name":"Yingxiang"},{"last_name":"Ma","full_name":"Ma, Hong","first_name":"Hong"}],"author":[{"full_name":"Zhong, Sheng","first_name":"Sheng","last_name":"Zhong"},{"last_name":"Lan","first_name":"Zijun","full_name":"Lan, Zijun"},{"last_name":"Ge","first_name":"Zengxiang","orcid":"0000-0001-9381-3577","full_name":"Ge, Zengxiang","id":"f43371a3-09ff-11eb-8013-bd0c6a2f6de8"},{"last_name":"Qu","full_name":"Qu, Li-Jia","first_name":"Li-Jia"}],"abstract":[{"lang":"eng","text":"In order to cope with arid terrestrial environments, angiosperms have evolved a unique fertilization way—siphonogamy. The success of siphonogamy requires several prerequisites, including the normal development of the female gametophyte and male gametophyte (pollen). Appropriate pollination methods ensure the successful encounter between pollen and the stigma. After pollen lands on the stigma, pollen/pollen tube interacts with different tissues and cells of the pistil, completing a series of male-female communications. The smooth progress of these interactions ensures that the pollen tube can enter the female gametophyte, burst, and release sperm cells to complete the double fertilization. In this chapter, we provide an overview of pollination and the interactions between male and female, comprehensively summarizing the factors involved in these processes."}],"OA_type":"closed access","das_tickbox":"1","language":[{"iso":"eng"}],"oa_version":"None","date_created":"2026-07-13T09:46:18Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","quality_controlled":"1","type":"book_chapter","date_published":"2026-04-24T00:00:00Z","place":"Singapore","date_updated":"2026-07-13T12:25:19Z","publication_status":"published","department":[{"_id":"JiFr"}],"page":"537-615","citation":{"chicago":"Zhong, Sheng, Zijun Lan, Zengxiang Ge, and Li-Jia Qu. “Pollination and Fertilization.” In Regulation of Plant Development, edited by Fang Chang, Yingxiang Wang, and Hong Ma, 537–615. Singapore: Springer Nature, 2026. https://doi.org/10.1007/978-981-95-7033-1_14.","apa":"Zhong, S., Lan, Z., Ge, Z., & Qu, L.-J. (2026). Pollination and Fertilization. In F. Chang, Y. Wang, & H. Ma (Eds.), Regulation of Plant Development (pp. 537–615). Singapore: Springer Nature. https://doi.org/10.1007/978-981-95-7033-1_14","mla":"Zhong, Sheng, et al. “Pollination and Fertilization.” Regulation of Plant Development, edited by Fang Chang et al., Springer Nature, 2026, pp. 537–615, doi:10.1007/978-981-95-7033-1_14.","ista":"Zhong S, Lan Z, Ge Z, Qu L-J. 2026.Pollination and Fertilization. In: Regulation of Plant Development. , 537–615.","ama":"Zhong S, Lan Z, Ge Z, Qu L-J. Pollination and Fertilization. In: Chang F, Wang Y, Ma H, eds. Regulation of Plant Development. Singapore: Springer Nature; 2026:537-615. doi:10.1007/978-981-95-7033-1_14","short":"S. Zhong, Z. Lan, Z. Ge, L.-J. Qu, in:, F. Chang, Y. Wang, H. Ma (Eds.), Regulation of Plant Development, Springer Nature, Singapore, 2026, pp. 537–615.","ieee":"S. Zhong, Z. Lan, Z. Ge, and L.-J. Qu, “Pollination and Fertilization,” in Regulation of Plant Development, F. Chang, Y. Wang, and H. Ma, Eds. Singapore: Springer Nature, 2026, pp. 537–615."}},{"publisher":"Springer Nature","OA_place":"publisher","doi":"10.1038/s42255-026-01451-w","file_date_updated":"2026-03-02T15:21:27Z","ddc":["570"],"fulldoi":"https://doi.org/10.1038/s42255-026-01451-w","day":"11","PlanS_conform":"1","publication_identifier":{"eissn":["2522-5812"]},"year":"2026","month":"02","_id":"21378","status":"public","publication":"Nature Metabolism","title":"Mitochondrial Ca2+ efflux controls neuronal metabolism and long-term memory across species","scopus_import":"1","oa":1,"article_processing_charge":"Yes (in subscription journal)","das_tickbox":"1","OA_type":"hybrid","abstract":[{"text":"From insects to mammals, essential brain functions, such as forming long-term memories (LTMs), increase metabolic activity in stimulated neurons to meet the energetic demand associated with brain activation. However, while impairing neuronal metabolism limits brain performance, whether expanding the metabolic capacity of neurons boosts brain function remains poorly understood. Here, we show that LTM formation of flies and mice can be enhanced by increasing mitochondrial metabolism in central memory circuits. By knocking down the mitochondrial Ca2+ exporter Letm1, we favour Ca2+ retention in the mitochondrial matrix of neurons due to reduction of mitochondrial H+/Ca2+ exchange. The resulting increase in mitochondrial Ca2+ over-activates mitochondrial metabolism in neurons of central memory circuits, leading to improved LTM storage in training paradigms in which wild-type counterparts of both species fail to remember. Our findings unveil an evolutionarily conserved mechanism that controls mitochondrial metabolism in neurons and indicate its involvement in shaping higher brain functions, such as LTM.","lang":"eng"}],"author":[{"last_name":"Amrapali Vishwanath","full_name":"Amrapali Vishwanath, Anjali","first_name":"Anjali"},{"last_name":"Comyn","first_name":"Typhaine","full_name":"Comyn, Typhaine"},{"first_name":"Rodrigo G.","full_name":"Mira, Rodrigo G.","last_name":"Mira"},{"first_name":"Claire","full_name":"Brossier, Claire","last_name":"Brossier"},{"last_name":"Pascual-Caro","full_name":"Pascual-Caro, Carlos","first_name":"Carlos"},{"last_name":"Faour","first_name":"Maya","full_name":"Faour, Maya"},{"last_name":"Boumendil","full_name":"Boumendil, Kahina","first_name":"Kahina"},{"first_name":"Chaitanya","orcid":"0000-0003-4252-1608","id":"BA06AFEE-A4BA-11EA-AE5C-14673DDC885E","full_name":"Chintaluri, Chaitanya","last_name":"Chintaluri"},{"full_name":"Ramon-Duaso, Carla","first_name":"Carla","last_name":"Ramon-Duaso"},{"last_name":"Fan","full_name":"Fan, Ruolin","first_name":"Ruolin"},{"last_name":"Ghosh","full_name":"Ghosh, Kishalay","first_name":"Kishalay"},{"last_name":"Farrants","first_name":"Helen","full_name":"Farrants, Helen"},{"first_name":"Jean-Paul","full_name":"Berwick, Jean-Paul","last_name":"Berwick"},{"last_name":"Sivakumar","first_name":"Riya","full_name":"Sivakumar, Riya"},{"last_name":"Lopez-Manzaneda","full_name":"Lopez-Manzaneda, Mario","first_name":"Mario"},{"first_name":"Eric R.","full_name":"Schreiter, Eric R.","last_name":"Schreiter"},{"last_name":"Preat","full_name":"Preat, Thomas","first_name":"Thomas"},{"last_name":"Vogels","full_name":"Vogels, Tim P","id":"CB6FF8D2-008F-11EA-8E08-2637E6697425","first_name":"Tim P","orcid":"0000-0003-3295-6181"},{"last_name":"Rangaraju","full_name":"Rangaraju, Vidhya","first_name":"Vidhya"},{"last_name":"Busquets-Garcia","full_name":"Busquets-Garcia, Arnau","first_name":"Arnau"},{"first_name":"Pierre-Yves","full_name":"Plaçais, Pierre-Yves","last_name":"Plaçais"},{"full_name":"Pavlowsky, Alice","first_name":"Alice","last_name":"Pavlowsky"},{"first_name":"Jaime","full_name":"de Juan-Sanz, Jaime","last_name":"de Juan-Sanz"}],"pmid":1,"article_type":"original","file":[{"relation":"main_file","checksum":"365932a599d05bc9ce8a57204e7a1465","file_id":"21392","date_updated":"2026-03-02T15:21:27Z","success":1,"file_name":"2026_NatureMetab_AmrapaliVishwanath.pdf","content_type":"application/pdf","creator":"dernst","file_size":5326608,"date_created":"2026-03-02T15:21:27Z","access_level":"open_access"}],"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)"},"department":[{"_id":"TiVo"}],"publication_status":"published","date_updated":"2026-07-13T12:30:14Z","date_published":"2026-02-11T00:00:00Z","has_accepted_license":"1","type":"journal_article","intvolume":" 8","quality_controlled":"1","date_created":"2026-03-02T10:04:49Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","language":[{"iso":"eng"}],"external_id":{"pmid":["41673453"]},"page":"467-488","citation":{"short":"A. Amrapali Vishwanath, T. Comyn, R.G. Mira, C. Brossier, C. Pascual-Caro, M. Faour, K. Boumendil, C. Chintaluri, C. Ramon-Duaso, R. Fan, K. Ghosh, H. Farrants, J.-P. Berwick, R. Sivakumar, M. Lopez-Manzaneda, E.R. Schreiter, T. Preat, T.P. Vogels, V. Rangaraju, A. Busquets-Garcia, P.-Y. Plaçais, A. Pavlowsky, J. de Juan-Sanz, Nature Metabolism 8 (2026) 467–488.","ieee":"A. Amrapali Vishwanath et al., “Mitochondrial Ca2+ efflux controls neuronal metabolism and long-term memory across species,” Nature Metabolism, vol. 8, no. 2. Springer Nature, pp. 467–488, 2026.","mla":"Amrapali Vishwanath, Anjali, et al. “Mitochondrial Ca2+ Efflux Controls Neuronal Metabolism and Long-Term Memory across Species.” Nature Metabolism, vol. 8, no. 2, Springer Nature, 2026, pp. 467–88, doi:10.1038/s42255-026-01451-w.","apa":"Amrapali Vishwanath, A., Comyn, T., Mira, R. G., Brossier, C., Pascual-Caro, C., Faour, M., … de Juan-Sanz, J. (2026). Mitochondrial Ca2+ efflux controls neuronal metabolism and long-term memory across species. Nature Metabolism. Springer Nature. https://doi.org/10.1038/s42255-026-01451-w","ama":"Amrapali Vishwanath A, Comyn T, Mira RG, et al. Mitochondrial Ca2+ efflux controls neuronal metabolism and long-term memory across species. Nature Metabolism. 2026;8(2):467-488. doi:10.1038/s42255-026-01451-w","ista":"Amrapali Vishwanath A, Comyn T, Mira RG, Brossier C, Pascual-Caro C, Faour M, Boumendil K, Chintaluri C, Ramon-Duaso C, Fan R, Ghosh K, Farrants H, Berwick J-P, Sivakumar R, Lopez-Manzaneda M, Schreiter ER, Preat T, Vogels TP, Rangaraju V, Busquets-Garcia A, Plaçais P-Y, Pavlowsky A, de Juan-Sanz J. 2026. Mitochondrial Ca2+ efflux controls neuronal metabolism and long-term memory across species. Nature Metabolism. 8(2), 467–488.","chicago":"Amrapali Vishwanath, Anjali, Typhaine Comyn, Rodrigo G. Mira, Claire Brossier, Carlos Pascual-Caro, Maya Faour, Kahina Boumendil, et al. “Mitochondrial Ca2+ Efflux Controls Neuronal Metabolism and Long-Term Memory across Species.” Nature Metabolism. Springer Nature, 2026. https://doi.org/10.1038/s42255-026-01451-w."},"issue":"2","project":[{"name":"What’s in a memory? Spatiotemporal dynamics in strongly coupled recurrent neuronal networks.","grant_number":"214316/Z/18/Z","_id":"c084a126-5a5b-11eb-8a69-d75314a70a87"}],"volume":8,"acknowledgement":"We thank all members of the laboratory of J.d.J.-S. for insightful discussions and comments. We thank S. Perez for technical assistance. This work was made possible by the Paris Brain Institute Diane Barriere Chair in Synaptic Bioenergetics awarded to J.d.J.-S., who is also supported by an ERC Starting Grant (SynaptoEnergy, European Research Council; ERC-StG-852873), 2019 ATIP-Avenir Grant (CNRS, Inserm), a Big Brain Theory Grant (ICM Foundation) and a Kavli Exploratory Award (Kavli Foundation). This work was also supported by an ERC Advanced Grant (EnergyMeMo; ERC-AdG-741550) to T.P. and grants from the Agence Nationale de la Recherche to P.Y.P. (ANR-20-CE92-0047-01), T.P. (ANR-23-CE16-0029-01), A.P. and J.d.J.-S. (ANR-22-CE16-0020) and J.d.J.-S. (ANR-24-CE16-0221). T.P., P.Y.P. and J.d.J.-S. are permanent CNRS researchers. A.P. is a permanent ESPCI associate professor. T.C. was funded by the French Ministry of Research and the Fondation pour la Recherche Médicale. V.R. was funded by the Max Planck Society, the Chan Zuckerberg Initiative DAF, an advised fund of the Silicon Valley Community Foundation grant number 2024-349543 and the NIH Director’s New Innovator Award (DP2 MH140148). A.B.-G. and C.R.-D. received funding from an ERC Starting Grant (HighMemory; ERC-StG-948217), the Ministry of Economy and Competitiveness (PID2021-122795OB-I00) and the Departament d’Economia i Coneixement de la Generalitat de Catalunya (SGR 00022). T.P.V. was funded by the Wellcome Trust and a Royal Society Sir Henry Dale Research Fellowship (WT100000) and a Wellcome Trust Senior Research Fellowship (214316/Z/18/Z). K.G. was supported by the DIM C-BRAINS, funded by the Conseil Régional d’Ile-de-France. The contributions of H.F. and E.R.S. were supported by the Howard Hughes Medical Institute. The PHENO-ICMice animal Core at ICM is supported by two ‘Investissements d’avenir’ (ANR-10- IAIHU-06 and ANR-11-INBS-0011-NeurATRIS) and the Fondation pour la Recherche Médicale."},{"author":[{"last_name":"Kokorev","first_name":"Vasily","full_name":"Kokorev, Vasily"},{"full_name":"Chisholm, John","first_name":"John","last_name":"Chisholm"},{"last_name":"Naidu","full_name":"Naidu, Rohan P.","first_name":"Rohan P."},{"first_name":"Seiji","full_name":"Fujimoto, Seiji","last_name":"Fujimoto"},{"last_name":"Atek","full_name":"Atek, Hakim","first_name":"Hakim"},{"full_name":"Brammer, Gabriel","first_name":"Gabriel","last_name":"Brammer"},{"last_name":"Finkelstein","first_name":"Steven L.","full_name":"Finkelstein, Steven L."},{"last_name":"Akins","first_name":"Hollis B.","full_name":"Akins, Hollis B."},{"last_name":"Berg","full_name":"Berg, Danielle A.","first_name":"Danielle A."},{"full_name":"Furtak, Lukas J.","first_name":"Lukas J.","last_name":"Furtak"},{"first_name":"Qinyue","full_name":"Fei, Qinyue","last_name":"Fei"},{"full_name":"Hsiao, Tiger Yu-Yang","first_name":"Tiger Yu-Yang","last_name":"Hsiao"},{"full_name":"Labbé, Ivo","first_name":"Ivo","last_name":"Labbé"},{"orcid":"0000-0003-2871-127X","first_name":"Jorryt J","full_name":"Matthee, Jorryt J","id":"7439a258-f3c0-11ec-9501-9df22fe06720","last_name":"Matthee"},{"first_name":"Julian B.","full_name":"Muñoz, Julian B.","last_name":"Muñoz"},{"first_name":"Pascal A.","full_name":"Oesch, Pascal A.","last_name":"Oesch"},{"full_name":"Pan, Richard","first_name":"Richard","last_name":"Pan"},{"full_name":"Rinaldi, Pierluigi","first_name":"Pierluigi","last_name":"Rinaldi"},{"last_name":"Saldana-Lopez","first_name":"Alberto","full_name":"Saldana-Lopez, Alberto"},{"first_name":"Daniel","full_name":"Schaerer, Daniel","last_name":"Schaerer"},{"last_name":"Volonteri","first_name":"Marta","full_name":"Volonteri, Marta"},{"full_name":"Zitrin, Adi","first_name":"Adi","last_name":"Zitrin"}],"abstract":[{"text":"The detection of strong Balmer breaks and absorption features in Little Red Dots (LRDs) suggests they host active galactic nuclei embedded within dense gas envelopes, potentially powered by super-Eddington accretion. We present GLIMPSE-17775, a luminous (Lbol ∼ 1045 erg s−1) LRD at z = 3.501 behind Abell S1063 (μ ∼ 2), observed with deep JWST/NIRCam and a ∼20 hr (80 hr delensed) NIRSpec G395M spectrum. The data reveal over 40 emission and absorption features, including a rich forest of low-ionization Fe ii lines and numerous broad hydrogen recombination transitions. We use this depth to test the dense-gas interpretation through five independent diagnostics. Nearly all permitted lines show exponential wings with consistent FWHM, a signature of Thomson scattering requiring ne ≳ 108 cm−3. Adopting this width yields MBH ∼ 106.7M⊙, a factor of 10 lower than Gaussian fits, and λEdd ∼ 1.8. Additional diagnostics support the same picture: a pronounced Balmer break (fν,4050/fν,3670 = 2.0 ± 0.1), enhanced He i λ7065 and λ10830 with P-Cygni absorption, Bowen-fluorescent O i λ8446–λ11290 emission requiring Lyβ pumping, and 16 Fe ii lines matching fluorescence models. These features indicate a dense (n ∼ 108 cm−3), partially ionized cocoon where scattering and fluorescence dominate line formation, providing strong evidence that at least some LRDs are powered by super-Eddington black hole growth in the early Universe.","lang":"eng"}],"das_tickbox":"1","article_number":"153","OA_type":"gold","scopus_import":"1","title":"The Deepest GLIMPSE of a dense gas cocoon enshrouding a Little Red Dot","article_processing_charge":"Yes","oa":1,"status":"public","_id":"22296","month":"06","year":"2026","publication":"The Astrophysical Journal","DOAJ_listed":"1","day":"10","publication_identifier":{"issn":["0004-637X"],"eissn":["1538-4357"]},"file_date_updated":"2026-07-13T13:23:11Z","OA_place":"publisher","doi":"10.3847/1538-4357/ae4ed7","publisher":"IOP Publishing","ddc":["520"],"fulldoi":"https://doi.org/10.3847/1538-4357/ae4ed7","volume":1004,"acknowledgement":"IOP Science home\r\nThe Astrophysical Journal\r\nThe American Astronomical Society, find out more.\r\n\r\nThe following article isOpen access\r\nThe Deepest GLIMPSE of a Dense Gas Cocoon Enshrouding a Little Red Dot\r\nVasily Kokorev, John Chisholm, Rohan P. Naidu, Seiji Fujimoto, Hakim Atek, Gabriel Brammer, Steven L. Finkelstein, Hollis B. Akins, Danielle A. Berg, Lukas J. FurtakShow full author list\r\n\r\nPublished 2026 June 10 • © 2026. The Author(s). Published by the American Astronomical Society.\r\nThe Astrophysical Journal, Volume 1004, Number 2\r\nCitation Vasily Kokorev et al 2026 ApJ 1004 153\r\nDOI 10.3847/1538-4357/ae4ed7\r\n\r\nPDFOpens in a new tab.ePub\r\nAuthors\r\nFigures\r\nTables\r\nReferences\r\nArticle data\r\nPDFOpens in a new tab.ePub\r\nArticle metrics\r\n5138 Total downloads\r\n\r\n22 total citations on Dimensions.\r\nShare this article\r\nArticle information\r\nAbstract\r\nThe detection of strong Balmer breaks and absorption features in Little Red Dots (LRDs) suggests they host active galactic nuclei embedded within dense gas envelopes, potentially powered by super-Eddington accretion. We present GLIMPSE-17775, a luminous (Lbol ∼ 1045 erg s−1) LRD at z = 3.501 behind Abell S1063 (μ ∼ 2), observed with deep JWST/NIRCam and a ∼20 hr (80 hr delensed) NIRSpec G395M spectrum. The data reveal over 40 emission and absorption features, including a rich forest of low-ionization Fe ii lines and numerous broad hydrogen recombination transitions. We use this depth to test the dense-gas interpretation through five independent diagnostics. Nearly all permitted lines show exponential wings with consistent FWHM, a signature of Thomson scattering requiring ne ≳ 108 cm−3. Adopting this width yields MBH ∼ 106.7M⊙, a factor of 10 lower than Gaussian fits, and λEdd ∼ 1.8. Additional diagnostics support the same picture: a pronounced Balmer break (fν,4050/fν,3670 = 2.0 ± 0.1), enhanced He i λ7065 and λ10830 with P-Cygni absorption, Bowen-fluorescent O i λ8446–λ11290 emission requiring Lyβ pumping, and 16 Fe ii lines matching fluorescence models. These features indicate a dense (n ∼ 108 cm−3), partially ionized cocoon where scattering and fluorescence dominate line formation, providing strong evidence that at least some LRDs are powered by super-Eddington black hole growth in the early Universe.\r\n\r\nExport citation and abstract\r\nBibTeXRIS\r\n\r\nPrevious article in issue\r\nNext article in issue\r\nRelated links\r\n\r\nOriginal content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.\r\n\r\n1. Introduction\r\nOne of the most enticing puzzles brought about by the launch of the James Webb Space Telescope (JWST) has been the discovery of red, compact objects called “Little Red Dots” (LRDs; J. Matthee et al. 2024). Previously invisible to the Hubble Space Telescope (HST) due to their extreme faintness in the optical and lack of near-infrared (NIR) coverage, LRDs have emerged in abundance (V. Kokorev et al. 2024a; H. B. Akins et al. 2025a; D. D. Kocevski et al. 2025; G. Barro et al. 2026) thanks to the unprecedented NIR sensitivity of JWST.\r\n\r\nTheir unusual properties—such as compact morphologies in rest-optical and distinctive “V-shaped” spectral energy distributions (SEDs)—make LRDs easy to identify in JWST fields; however, this is where the simplicity ends. Explaining LRDs as either evolved or dusty compact galaxies proves difficult: The former scenario requires massive stellar populations that strain Lambda cold dark matter (ΛCDM) predictions (M. Boylan-Kolchin 2023; I. Labbé et al. 2023), while the latter implies significant dust emission, yet none is observed (C. M. Casey et al. 2024; G. C. K. Leung et al. 2025; H. B. Akins et al. 2025a; I. Labbé et al. 2025).\r\n\r\nOver time, the accumulating detections of broad Balmer-series emission lines (D. D. Kocevski et al. 2023, 2025; J. Matthee et al. 2024, just to name a few), often accompanied by signatures of extreme ionization (e.g., V. Kokorev et al. 2023), have begun to clarify the physical origin of LRDs, pointing increasingly toward active galactic nuclei (AGN) as the underlying power source. In parallel, the much needed advent of NIRSpec Micro Shutter Assembly (MSA) programs based on red targets selected from JWST imaging (e.g., A. de Graaff et al. 2025b) has provided critical confirmation: Nearly all point sources exhibiting “V-shaped” SEDs reveal broad emission lines upon spectroscopic follow-up (R. E. Hviding et al. 2025), solidifying their AGN interpretation.\r\n\r\nThe nature of the spectral inflection point in LRDs, typically located near ∼3600 Å, has also undergone significant revision. Initially interpreted as a stellar Balmer break (I. Labbé et al. 2023), this feature implied implausibly high stellar masses (M*) far too early in cosmic history (M. Boylan-Kolchin 2023; N. Sabti et al. 2024). A second hypothesis invoked differential dust attenuation and host-galaxy contamination in the rest-UV to explain the sharp discontinuity (M. Volonteri et al. 2025). However, this explanation was soon ruled out by D. J. Setton et al. (2025) and Y. Ma et al. (2025), who demonstrated that the break generally lies around the Balmer limit, albeit with a fundamentally different origin than initially proposed.\r\n\r\nMore recently, a series of theoretical and observational works have converged on a new picture in which LRDs may host accreting black holes enshrouded in exceptionally dense, partially ionized gas cocoons, often referred to as “black hole stars” (hereafter BH*; A. de Graaff et al. 2025b; K. Inayoshi & R. Maiolino 2025; R. P. Naidu et al. 2025; A. J. Taylor et al. 2025). Here, BH* is used in an empirical sense to denote cocooned black holes whose emergent spectra exhibit a combination of black-hole-like and star-like features, such as broad permitted lines, steep Balmer-limit breaks, and Balmer absorption, as observed in the archetypal BH* sources (A. de Graaff et al. 2025b; R. P. Naidu et al. 2025). This usage does not assume a specific geometry or formation channel: The underlying physical picture involves an AGN power-law ionizing spectrum processed through very dense gas, and similar phenomenology can arise in a range of dense-gas configurations (e.g., K. Inayoshi & R. Maiolino 2025; D. Kido et al. 2025; H. Liu et al. 2025; A. Sneppen et al. 2026). In such environments, suppressed X-ray and radio emission (e.g., K. Inayoshi & R. Maiolino 2025; R. P. Naidu et al. 2025) arise naturally from the high optical depth, while the UV emission and forbidden optical lines (e.g., [O iii] λλ4959, 5007) may originate in the more extended host (e.g., A. de Graaff et al. 2025d).\r\n\r\nThe dense-gas interpretation also offers a natural explanation for the P-Cygni-like Balmer and helium profiles frequently seen in high-signal-to-noise-ratio (S/N) spectra (J. Matthee et al. 2024), the non-Gaussian, exponentially winged line shapes predicted by radiative-transfer models of scattering in ionized gas (S.-J. Chang et al. 2026; V. Rusakov et al. 2026), and Lyα-like resonantly scattered shapes (R. P. Naidu et al. 2025; S.-J. Chang et al. 2026). Intriguingly, if electron and resonant scattering indeed dominate the broad-line widths, then the true virial velocities (traced by intrinsically narrower Gaussian cores)—and hence black hole masses—could be lower by an order of magnitude, alleviating the apparent tension between LRD black hole masses and their compact host galaxies (V. Rusakov et al. 2026).\r\n\r\nSo far, however, the BH*/dense-gas interpretation of LRDs has relied largely on the Balmer break, occasional absorption features (X. Lin et al. 2026), and, to a limited extent, the shapes of broad emission lines (V. Rusakov et al. 2026). While these features are consistent with the presence of dense, partially ionized gas, they stop short of providing direct spectroscopic confirmation of the physical conditions expected by the BH* scenario. What has been missing is an unambiguous demonstration—through emission-line physics—that LRDs indeed host dense, optically thick cocoons surrounding rapidly accreting black holes. Such evidence would directly tie the observed line formation, excitation, and radiative transfer to dense, stratified envelopes of gas surrounding the central engine.\r\n\r\nIn this work, we present precisely such a case: an exceptionally deep, ∼20 hr (equivalent to 80 hr without lensing magnification) JWST/NIRSpec G395M spectrum of a luminous LRD at z = 3.50102. The target, GLIMPSE-17775, lies in a highly magnified region of the massive galaxy cluster Abell S1063 (hereafter AS1063) and benefits from the combined power of JWST/NIRCam imaging from the GLIMPSE GO program (PID 3293; PIs: H. Atek & J. Chisholm) and recent NIRSpec spectroscopy from the GLIMPSEDirector's Discretionary Time (DDT) (hereafter GLIMPSE-D) program (PID 9223; PIs: S. Fujimoto & R. Naidu). This synergy of ultradeep spectroscopy and strong gravitational lensing enables an unprecedented view of GLIMPSE-17775, revealing rest-frame optical and NIR features at a level unseen before in any LRD. We detect over 40 emission and absorption features, including 16 Fe ii transitions that form a dense “iron forest.” The remarkable richness of this spectrum makes GLIMPSE-17775 a uniquely powerful laboratory for dissecting the dense, radiation-dominated environments that accompany early black hole growth.\r\n\r\nThis paper is organized as follows. In Section 2, we present the GLIMPSE-D NIRSpec dataset alongside the photometric datasets used in this study. In Section 3, we calculate the spectroscopic redshift, describe the identification of prominent emission/absorption features, and describe bespoke fitting of various line complexes. Section 4 describes the measurement of the source morphology, dust attenuation, and black hole masses. In Section 5, we comment on the various properties of the emission features in the our target. Finally, we discuss our findings in Section 6.\r\n\r\nThroughout this work, we assume a flat ΛCDM cosmology with Ωm,0 = 0.3, ΩΛ,0 = 0.7, and H0 = 70 km s−1 Mpc−1, and a G. Chabrier (2003) initial mass function between 0.1 and 100M⊙. All magnitudes are expressed in the AB system (J. B. Oke 1974).\r\n\r\n2. Observations and Data\r\nThe target, GLIMPSE-17775, was originally identified as a bright LRD candidate in JWST/NIRCam imaging captured by the GLIMPSE (PID: 3293; PIs: H. Atek & J. Chisholm) survey (H. Atek et al. 2025) of the lensed AS1063 Hubble Frontier Field (HFF; J. M. Lotz et al. 2017). The highly magnified area of AS1063 has already successfully yielded z > 16 galaxy candidates (V. Kokorev et al. 2025), potential Population III (Pop III) hosts (S. Fujimoto et al. 2025a), numerous faint and high-redshift galaxies (I. Chemerynska et al. 2026), new constraints on reionization (D. Korber et al. 2025), identification of intermediate-mass black holes (Q. Fei et al. 2025), and a wide variety of enigmatic LRDs, some moderately lensed. The LRD selection was based on the standard compactness plus “V-shape” criteria already laid out in J. E. Greene et al. (2024), V. Kokorev et al. (2024a), H. B. Akins et al. (2025a), and I. Labbé et al. (2025) using photometric redshifts derived with eazy (G. B. Brammer et al. 2008), a technique that has proven successful at consistently identifying many exciting sources (see, e.g., H. B. Akins et al. 2025b; A. de Graaff et al. 2025b; V. Kokorev et al. 2023; R. P. Naidu et al. 2025; A. J. Taylor et al. 2025). Located at zphot = 4.2 ± 0.1, GLIMPSE-17775 stood out in particular due to its extreme rest-optical brightness with mf444w ∼ 23.6 mag and a modest lensing magnification μ ∼ 2. While very little could be done with photometry alone, this marked GLIMPSE-17775 as a promising target for any future spectroscopic follow-up.\r\n\r\n2.1. Photometry\r\nWe use photometry both to select targets for the GLIMPSE-D NIRSpec observations and, during spectroscopic modeling, to constrain the overall shape of the SED and correct for NIRSpec slit losses. In addition to JWST/NIRCam data, we incorporate deep HST Advanced Camera for Surveys and Wide Field Camera 3 imaging from the HFF (J. M. Lotz et al. 2017) and BUFFALO (C. L. Steinhardt et al. 2020) programs. Our reprocessed HST mosaics are based on Gaia-aligned images from the CHArGE archive (V. Kokorev et al. 2022), hosted on the Dawn JWST Archive (F. Valentino et al. 2023). More descriptions of the image reduction and source extraction procedure can be found in R. Endsley et al. (2025), as well as in the GLIMPSE overview paper (H. Atek et al. 2025); we briefly summarize the latter procedure below.\r\n\r\nPhotometry is performed on point-spread function (PSF)-homogenized HST and JWST images, convolved to the resolution of the F480M filter. Source detection is carried out using SExtractor (E. Bertin & S. Arnouts 1996) through two parallel steps. We construct two inverse-variance-weighted detection images: one from the short-wavelength (SW; F090W, F115W, F150W, F200W) bands to preserve spatial resolution, and one from the long-wavelength (LW; F277W, F356W, F444W) bands to ensure sensitivity to red or dusty sources (e.g., LRDs). Unlike the science images, these have not been PSF-matched. These SW and LW detection catalogs are subsequently merged into a single, combined catalog. Photometry is then measured using photutils (L. Bradley et al. 2020) in a range of circular apertures (–). Photometric uncertainties are estimated by placing random apertures in empty regions around each source. Unless stated otherwise, we adopt total fluxes measured within a aperture throughout this work.\r\n\r\n2.2. NIRSpec Observations\r\nGLIMPSE-D NIRSpec data were obtained during a campaign (DDT #9223; PIs: S. Fujimoto & R. Naidu) to study a promising Pop III galaxy candidate (S. Fujimoto et al. 2025a). GLIMPSE-D obtained a total of three G395M/F295LP MSA pointings, totaling 29.78 hr of total exposure time. The pointing center differed for each of the three configurations to maximize the total object yield. In total, the GLIMPSE-D sample contains 384 spectra, with depths varying from 9.2 hr to ∼30 hr. All of the planned observations were successfully executed between 2025 June 30 and July 2. For each MSA configuration, GLIMPSE-D employed a standard three-point nod pattern at an aperture position angle PA_V3 = 2705, using 494 groups per integration with the NRSIRS2 readout mode. The full details of the target selection, prioritization, and MSA planning will be presented in a forthcoming survey paper (S. Fujimoto et al. 2025b).\r\n\r\n2.3. G395M Data Reduction and Calibration\r\nThe GLIMPSE-D MSA spectra were uniformly reduced using msaexp (v0.9.8; G. Brammer 2022). This procedure starts with the level-2 calibrated products obtained from MAST and applies a number of corrections that include 1/f noise, artifact detection and removal, and a bias correction in individual exposures (see J. Rigby et al. 2023 for more details). Together with the JWST pipeline, msaexp sets the slit World Coordinate System, performs flat-fielding, and computes an initial pass-loss correction. Each one of the two-dimensional shutters is then drizzled onto a common pixel grid. Using the standard approach, the background subtraction is performed locally using stacked, source-free shutters. The one-dimensional spectra are then obtained via the optimal extraction method (e.g., P. Arrabal Haro et al. 2023; A. de Graaff et al. 2024), in which the center and width of the extraction “aperture” vary depending on the best-fit Gaussian model (K. Horne 1986), similar to the methodology widely adopted by a variety of other works (e.g., B. Wang et al. 2023; J. E. Greene et al. 2024; V. Kokorev et al. 2024b).\r\n\r\nThe absolute flux calibration of MSA spectra can be influenced by several factors, including the position of the source within the shutter, calibration and astrometric uncertainties, and the intrinsic morphology of the source. To correct for these effects and derive an overall slit-loss correction, we rescale the extracted one-dimensional spectra by convolving them with all available NIRCam filters and comparing the resulting flux densities to the total photometry from the GLIMPSE catalog. A wavelength-dependent correction is then obtained by fitting a second-order polynomial to these differences.\r\n\r\nThe target in this paper was observed in all three configurations; however, one was severely contaminated by sources in the same row, making the data recovery for that configuration unfeasible. Despite this, GLIMPSE-17775 is securely detected in two configurations (33,262 s and 40,703 s), yielding a total integration time of 20.55 hr. We combine the extracted and separately calibrated one-dimensional spectra using inverse-variance weighting. The stacked spectrum is shown in Figure 1. We also make the spectrum publicly available.17\r\n\r\nZoom InZoom OutReset image size\r\nFigure 1. Top: JWST/NIRCam and HST 20 stamps and red, green, blue short-wavelength (SW) and long-wavelength (LW) color images, comprising the F115W, F150W, and F200W and F277W, F356W, and F444W bands, respectively. MSA shutters for both configurations covering GLIMPSE-17775 are shown in blue and red, respectively. The source morphology is resolved and extended up to ∼2 μm, and then appears to transition to a more PSF-dominated and compact shape, echoing a growing sample of LRDs with extended rest-UV morphology (I. Juodžbalis et al. 2024; I. Labbe et al. 2024; J. Matthee et al. 2024; P. Rinaldi et al. 2025a). This likely hints at the presence of the host galaxy in the filters covering the rest-UV. In each panel, we show the total AB magnitude as presented in the GLIMPSE catalog (H. Atek et al. 2025; V. Kokorev et al. 2025). The source is exceptionally bright (M444 ∼ 23.6) and is detected in most JWST bands at >100σ. Middle: two-dimensional MSA G395M spectra covering GLIMPSE-17775. Bottom: combined one-dimensional spectrum (see, e.g., V. Kokorev et al. 2023; A. de Graaff et al. 2025a for the extraction method) of the LRD in the observed frame. We show the data in black, and the uncertainty as a black shaded region. Fixing the systemic redshift to the [S iii] λ9071 line (zspec = 3.50102 ± 0.00019), we show the positions and label the prominent emission with significant (≥3σ) detections as solid vertical lines. Iron lines are shown separately in green. Due to the sheer number of features, not all could be labeled; we therefore display all features in Figure 2. Emission lines for which only upper limits are obtained are shown with dashed lines.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\n3. Emission-line Analysis\r\n3.1. Spectroscopic Redshift\r\nThe spectrum of GLIMPSE-17775 reveals a remarkably wide variety of significantly detected emission and absorption lines. Before focusing on individual features and their complex components, we perform an initial tally of all detectable lines using a heavily modified version of msaexp (G. Brammer 2022; V. Kokorev et al. 2024b). The key modifications allow varying the line widths and fitting multiple components, albeit tied to the same redshift.\r\n\r\nWe fit the full spectrum using msaexp, adopting Gaussian profiles for emission lines and a three-segment cubic spline to model the continuum. This minimal spline structure, appropriate given the high average S/N of GLIMPSE-17775 (≳30), helps prevent overfitting, particularly of features that may be slightly offset in wavelength or velocity space from the average redshift. Emission-line positions are fixed; narrow components are allowed a FWHM between 150 and 800 km s−1, and permitted transitions may include a broad component (800–5000 km s−1).\r\n\r\nThis yields a redshift of zspec = 3.5010 ± 0.0001 (see Table 1). However, several strong lines exhibit significant pixel-level offsets of 100–200 km s−1 relative to this value. These discrepancies are statistically robust and appear in both stacked and individual spectra, suggesting that the derived redshift reflects a weighted average dominated by high-S/N lines. To properly assess velocity structure, a consistent systemic redshift is required. In the following sections describing the detailed line analysis, we adopt the centroid of a narrow forbidden line as the systemic reference frame (specifically [S iii] λ9071; see Section 3.3).\r\n\r\nUsing the updated redshift alongside the strong-lensing model of AS1063 (A. Zitrin et al. 2015; L. Furtak et al. 2026, in preparation), we recalculate the lensing magnification to be μ = 2.04 ± 0.21, consistent with previous estimates based on zphot. With redshift and magnification now fixed, we turn to a deeper analysis of the emission-line properties.\r\n\r\n3.2. Line Identification\r\nBeyond velocity offsets, the initial msaexp fit highlights several notable features. Broad hydrogen lines, ubiquitous in LRDs (e.g., D. D. Kocevski et al. 2023; V. Kokorev et al. 2023; L. J. Furtak et al. 2024; J. Matthee et al. 2024; A. de Graaff et al. 2025b; R. E. Hviding et al. 2025; R. P. Naidu et al. 2025; A. J. Taylor et al. 2025), are strongly favored across the Balmer and Paschen series, with Δχ2 > 10. These include Hα and Pa10 through Paγ. Although Paβ falls near the edge of the detector, we nonetheless observe a prominent broad wing at its expected location (see Figure 1).\r\n\r\nBroad components are also detected in several helium and oxygen lines: He i λ6680, He i λ7065, O i λ8448, He i λ10830, and O i λ11290. Notably, the He i λ10830 line shows a classic P-Cygni profile with a clear blueshifted absorption trough. While Balmer absorption is becoming a familiar sight in LRDs (R. Maiolino et al. 2024; J. Matthee et al. 2024; A. de Graaff et al. 2025b; D. D. Kocevski et al. 2025; R. P. Naidu et al. 2025), helium absorption remains rare, with only a few published cases at high z (e.g., I. Juodžbalis et al. 2024; R. P. Naidu et al. 2024; B. Wang et al. 2025). Curiously, this was also recently reported in local analogs of LRDs (X. Lin et al. 2026).\r\n\r\nThe most striking feature is the detection of an extensive Fe ii emission forest in the rest-NIR—at least 16 distinct features are identified by msaexp and highlighted in green in Figure 1. Previous detections of permitted Fe ii in LRDs have been mostly limited to rest-UV/optical wavelengths using low-resolution PRISM spectra (R. Tripodi et al. 2025), with only few examples in the NIR (e.g., see broad Fe iiλ9200 I. Labbe et al. 2024). Iron has also been identified in local LRD analogs (X. Lin et al. 2026; X. Ji et al. 2026). Only recently have a few Fe ii emitters been reported in medium-resolution (F. D’Eugenio et al. 2025) and high-resolution spectra (A. Torralba et al. 2026). The richness of these lines in GLIMPSE-17775 hints at a dense, partially shielded gas phase, where processes such as Lyβ fluorescence and continuum pumping may be enhancing Fe ii emission (T. A. A. Sigut & A. K. Pradhan 1998, 2003; T. A. A. Sigut et al. 2004), offering a new diagnostic window into early AGN environments.\r\n\r\nIn summary, GLIMPSE-17775 exhibits an exceptionally rich and kinematically complex array of emission and absorption features. While the initial msaexp modeling provides a solid foundation for redshift estimation and line identification, it lacks the flexibility to capture the full diversity of line profiles in this high-S/N dataset. In the following sections, we peel back the spectral layers with increasing precision.\r\n\r\n3.3. Line Fitting\r\nThe exceptional depth of the G395M spectrum for GLIMPSE-17775 enables detailed modeling of both multiple kinematic components and potential velocity offsets between line species. Unless noted otherwise, each line is fit with a single Gaussian narrow component (FWHM = 100−800 km s−1). For permitted lines flagged by msaexp as potentially broad, we follow the approach of V. Rusakov et al. (2026) and model the profile as an intrinsic Gaussian core broadened by electron scattering, implemented via convolution with an exponential-wing component. The intrinsic Gaussian FWHM is allowed to vary between 500 and 5000 km s−1. The characteristic scattering width (i.e., the strength of the exponential wings, W) is treated as a free parameter and is allowed to vary independently between different transitions. For each broad line, we also perform an alternative fit with the W parameter fixed to zero (pure Gaussian) and compare the resulting goodness of fit to assess whether the exponential wings are statistically required. Line centers are allowed to vary independently unless otherwise specified.\r\n\r\nAbsorption lines are modeled using a Gaussian optical-depth profile, where the observed flux is Fobs = Fem e−τ(λ), where . The free parameters are then the central optical depth τ0, velocity width Δvabs, and redshift zabs (see I. Juodžbalis et al. 2024). Widths and redshifts (for both narrow and broad components) are typically free, with redshift limited to ± 0.1 from the msaexp value. Local continua are fit using first-order polynomials.\r\n\r\nAll individual model components are first initialized and coadded on an oversampled wavelength grid. To take into account the wavelength-dependent resolution of the grating, we interpolate our model onto a variable step grid while making sure that the total integrated flux is preserved. Further, we increase the nominal spectral resolution by a factor of 1.7, as it has been shown that the spectral resolution for a pointlike source falling within a shutter is higher than that of a uniformly illuminated slitlet (A. de Graaff et al. 2024). Fitting uses nonlinear χ2 minimization, with uncertainties derived from multivariate resampling of the covariance matrix.\r\n\r\nTable 1. Source Properties\r\n\r\nParametera\tGLIMPSE-17775\r\nID\t17775\r\nR.A. [deg]\t342.20080\r\nDecl. [deg]\t–44.54366\r\nzphot (eazy)\t4.2 ± 0.1\r\nzspec ([S iii] λ9071)\t3.50102 ± 0.00019\r\nμ\t2.04 ± 0.21\r\nMUV [AB mag]\t−17.27 ± 0.05\r\nreff,UV [pc]\t1000 ± 200\r\nreff,opt [pc]\t<300\r\nβ\t–0.69 ± 0.12\r\nlog10(MBH/M⊙)\t6.65 ± 0.15\r\nLbol [erg s−1]\t(1.06 ± 0.14)×1045\r\nλedd\t1.86 ± 0.25\r\nlog10(M*/M⊙)\t<7.5\r\nAV\t0.1 ± 0.3\r\nfν,4050Å/fν,3670Å\t2.02 ± 0.10\r\nNote. aPhysical parameters are corrected for the lensing magnification.\r\n\r\nDownload table as: \r\nASCIITypeset image\r\n\r\nGiven the complexity, the spectrum is divided into six windows grouped by line species or proximity (see Figure 2). Below, we describe the assumptions adopted for each window. Final fluxes and equivalent widths of the narrow and broad lines are listed in Tables 2 and 3, respectively, while kinematics are reported in Tables 4 and 5. We show detailed line fits in Figure 2.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 2. A staggering abundance of spectral lines in GLIMPSE-17775 at z = 3.501. For each spectral window defined in Section 3.3, we show the data (black), the best-fit narrow and broad components (dark purple and blue), and the total best-fit model including the continuum (red). All broad components were fit with models allowing exponential wings. The ΔBIC between exponential and Gaussian fits is reported in the top right of each panel; negative values indicate a preference for an exponential profile. The lower panels display the uncertainty-weighted residuals for each fit.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nTable 2. Fluxes of Narrow Emission Lines and Their Rest-frame Equivalent Widthsa\r\n\r\nLine\tλrest\tFlux\tEW0\r\n \t(Å)\t(10−20 erg s−1 cm−2)\t(Å)\r\nNarrow Emission Lines\r\nO i\t6302.0\t54.0 ± 21.2\t3.3 ± 1.2\r\n[N ii]\t6549.0\t25.6 ± 10.3\t1.6 ± 0.7\r\nHα\t6562.8\t2622.9 ± 200.7\t167.7 ± 12.8\r\n[N ii]\t6584.0\t77.1 ± 37.1\t4.9 ± 1.6\r\nHe i\t6680.0\t14.7 ± 11.1\t0.8 ± 0.7\r\n[S ii]\t6717.0\t22.2 ± 0.1\t1.5 ± 0.7\r\n[S ii]\t6731.0\t21.4 ± 0.1\t1.4 ± 0.5\r\nHe i\t7065.0\t461.7 ± 210.2\t31.0 ± 12.2\r\n[Ar iii]\t7138.0\t12.6 ± 3.4\t1.0 ± 0.3\r\nFe ii\t7156.0\t26.2 ± 7.2\t1.8 ± 0.2\r\n[O ii]\t7323.0\t26.0 ± 23.0\t1.7 ± 1.5\r\n[O ii]\t7325.0\t16.9 ± 1.8\t1.2 ± 0.1\r\n[O ii]\t7332.0\t26.2 ± 9.1\t1.8 ± 0.6\r\nFe ii\t8228.0\t23.7 ± 4.2\t2.0 ± 0.3\r\nFe ii\t8239.0\t7.2 ± 4.0\t0.6 ± 0.3\r\nFe ii\t8289.0\t6.3 ± 3.7\t0.5 ± 0.3\r\nFe iii\t8306.0\t5.7 ± 3.6\t0.5 ± 0.3\r\nO i\t8448.0\t67.6 ± 2.4\t6.1 ± 1.3\r\nFe ii\t8470.0\t16.2 ± 5.0\t1.4 ± 0.4\r\nFe ii\t8490.0\t26.7 ± 4.3\t2.4 ± 0.4\r\nPa10\t9015.0\t16.5 ± 5.0\t1.8 ± 0.5\r\n[S iii]\t9071.0\t27.2 ± 2.3\t3.5 ± 0.3\r\nFe ii\t9075.0\t30.0 ± 4.7\t3.4 ± 0.5\r\nFe ii\t9125.0\t16.8 ± 5.2\t1.9 ± 0.6\r\nFe ii\t9134.0\t36.9 ± 5.0\t4.1 ± 0.6\r\nFe ii\t9179.0\t95.0 ± 5.5\t10.6 ± 0.6\r\nFe ii\t9204.0\t50.1 ± 6.1\t5.6 ± 0.7\r\nPa9\t9229.0\t19.4 ± 7.0\t2.2 ± 0.8\r\nFe ii\t9394.0\t17.3 ± 3.9\t2.0 ± 0.5\r\n[S iii]\t9533.0\t84.7 ± 5.9\t10.2 ± 0.7\r\nPa8\t9545.0\t44.8 ± 11.3\t5.4 ± 1.4\r\nFe ii\t9997.0\t29.5 ± 4.5\t3.8 ± 0.6\r\nPaδ\t10049.0\t104.2 ± 12.2\t13.7 ± 1.7\r\nFe ii\t10490.0\t8.0 ± 2.7\t1.1 ± 0.4\r\nFe ii\t10501.0\t24.4 ± 5.9\t3.1 ± 0.8\r\nHe i\t10830.0\t163.0 ± 96.0\t22.6 ± 13.3\r\nPaγ\t10938.0\t146.3 ± 25.5\t20.9 ± 3.8\r\nFe ii\t11128.0\t12.3 ± 3.7\t1.8 ± 0.6\r\nO i\t11290.0\t49.2 ± 4.1\t7.7 ± 2.3\r\nNote. aNot corrected for lensing magnification.\r\n\r\nDownload table as: \r\nASCIITypeset image\r\n\r\nTable 3. Fluxes of Broad Emission Lines and Their Rest-frame Equivalent Widthsa\r\n\r\nLine\tλrest\tFlux\tEW0\r\n \t(Å)\t(10−20 erg s−1 cm−2)\t(Å)\r\nBroad Emission Lines\r\nHα\t6562.8\t14803.5 ± 198.6\t946.3 ± 15.6\r\nHe i\t6680.0\t144.6 ± 44.7\t9.4 ± 2.9\r\nHe i\t7065.0\t824.2 ± 210.0\t55.4 ± 15.1\r\nPa10\t9015.0\t53.7 ± 11.1\t5.8 ± 1.3\r\nPa9\t9229.0\t119.0 ± 13.5\t13.6 ± 1.5\r\nPa8\t9545.0\t191.2 ± 17.0\t23.1 ± 2.1\r\nPaδ\t10049.0\t370.6 ± 15.0\t48.8 ± 2.3\r\nHe i\t10830.0\t2294.9 ± 212.6\t318.8 ± 30.3\r\nPaγ\t10938.0\t652.3 ± 14.0\t92.9 ± 2.4\r\nO i\t8448.0\t93.7 ± 7.9\t8.4 ± 0.7\r\nO i\t11290.0\t106.2 ± 63.9\t16.6 ± 10.4\r\nNote. aNot corrected for lensing magnification.\r\n\r\nDownload table as: \r\nASCIITypeset image\r\n\r\nTable 4. Kinematic Properties of Narrow Lines\r\n\r\nLine\tλrest\tFWHM\tΔv\r\n \t(Å)\t(km s−1)\t(km s−1)\r\nNarrow Emission Lines\r\n[O i]\t6300.3\t455 ± 175\t−101 ± 81\r\nHα\t6562.8\t304 ± 8\t+145 ± 13\r\n[N ii]\t6583.4\t347 ± 117\t+84 ± 47\r\n[S ii]\t6716.4\t232 ± 62\t+82 ± 33\r\n[S ii]\t6731\t232 ± 62\t+82 ± 33\r\nHe i\t6678.2\t87 ± 14\t+40 ± 14\r\nHe i\t7065.2\t408 ± 644\t+112 ± 396\r\n[Ar iii]\t7135.8\t89 ± 50\t−26 ± 20\r\nFe ii\t7155.2\t96 ± 50\t+15 ± 15\r\n[O ii]\t7320.0\t400 ± 120\t−37 ± 72\r\nFe ii\t8228.0\t290 ± 48\t+21 ± 5\r\nFe ii\t8239.0\t290 ± 48\t+21 ± 5\r\nFe ii\t8289.0\t290 ± 48\t+21 ± 5\r\nFe iii\t8306.0\t290 ± 48\t+21 ± 5\r\nO i\t8446.4\t235 ± 30\t−43 ± 19\r\nFe ii\t8470.0\t290 ± 48\t+21 ± 5\r\nFe ii\t8490.0\t290 ± 48\t+21 ± 5\r\nPa10\t9014.9\t259 ± 36\t−46 ± 19\r\n[S iii]\t9071.0\t230 ± 13\t⋯\r\nFe ii\t9075.0\t486 ± 24\t−21 ± 17\r\nFe ii\t9125.0\t486 ± 24\t−21 ± 17\r\nFe ii\t9134.0\t486 ± 24\t−21 ± 17\r\nFe ii\t9179.0\t486 ± 24\t−21 ± 17\r\nFe ii\t9204.0\t486 ± 24\t−21 ± 17\r\nPa9\t9229.0\t259 ± 35\t−46 ± 19\r\nFe ii\t9394.0\t486 ± 24\t−21 ± 17\r\nPa8\t9545.6\t259 ± 36\t−46 ± 19\r\n[S iii]\t9533\t230 ± 13\t+23 ± 13\r\nFe ii\t9997.0\t331 ± 55\t+90 ± 25\r\nPaδ\t10049.4\t332 ± 22\t+21 ± 15\r\nHe i\t10830.3\t287 ± 46\t+112 ± 26\r\nPaγ\t10938.1\t267 ± 25\t+26 ± 17\r\nFe ii\t10490.0\t332 ± 96\t+44 ± 43\r\nFe ii\t10501.0\t332 ± 96\t+44 ± 43\r\nFe ii\t11128.0\t153 ± 116\t+37 ± 30\r\nO i\t11290.0\t260 ± 58\t−33 ± 24\r\nNote. Velocity offsets (Δv) calculated relative to [S iii] λ9071 at z = 3.50102.\r\n\r\nDownload table as: \r\nASCIITypeset image\r\n\r\nTable 5. Kinematic Properties of Broad and Absorption Lines\r\n\r\nLine\tλrest\tFWHM\tW\tΔv\r\n \t(Å)\t(km s−1)\t(km s−1)\t(km s−1)\r\nBroad Emission Lines\r\nHα\t6562.8\t1024 ± 21\t3010 ± 450\t−7 ± 16\r\nHe i\t6678.2\t1041 ± 792\t3890 ± 2083\t−137 ± 151\r\nHe i\t7065.2\t473 ± 116\t1000 ± 600\t−136 ± 82\r\nO i\t8446.4\t562 ± 331\t1120 ± 590\t+39 ± 80\r\nPa10\t9014.9\t766 ± 202\t2100 ± 600\t−155 ± 39\r\nPa9\t9229.0\t766 ± 202\t2100 ± 600\t−155 ± 39\r\nPa8\t9545.6\t766 ± 202\t2100 ± 600\t−155 ± 39\r\nPaδ\t10049.4\t1672 ± 458\t3500 ± 400\t+23 ± 44\r\nHe i\t10830.3\t536 ± 45\t2760 ± 220\t+154 ± 22\r\nPaγ\t10938.1\t1035 ± 322\t2400 ± 260\t−75 ± 31\r\nO i\t11287.0\t1188 ± 1099\t4300 ± 2000\t+245 ± 214\r\nAbsorption Lines\r\nHα\t6562.8\t1000 ± 123\t⋯\t−200 ± 32\r\nHe i\t7065.2\t587 ± 1024\t⋯\t−52 ± 83\r\nHe i\t10830.3\t794 ± 21\t⋯\t+45 ± 22\r\nNote. Velocity offsets (Δv) calculated relative to [S iii] λ9071 at z = 3.50102.\r\n\r\nDownload table as: \r\nASCIITypeset image\r\n\r\n3.3.1. Hα Complex\r\nHα is modeled with independent narrow, broad, and absorption components. [O i] λ6302 and He i λ6680 are modeled with narrow and broad profiles. [N ii] lines are fixed at a 1:3 ratio and share kinematics; [S ii] lines have independent amplitudes but tied velocities and widths.\r\n\r\nWe find that broad Hα and He i λ6680 are strongly favored to have exponential wings (ΔBIC ∼ −500), yielding a FWHM (of the intrinsic Gaussian core) of ∼1000 km s−1—significantly narrower than the ∼3000 km s−1 derived from pure Gaussians. Although no distinct Hα absorption component is explicitly detected, likely due to insufficient resolution, the overall asymmetry of the line is best reproduced when a weak, blueshifted absorber is included in the fit. This may indicate subtle self-absorption or partial obscuration within the dense cocoon. We return to the implications of this profile shape later.\r\n\r\n3.3.2. He i λ7065\r\nThe He i λ7065 line shows a prominent blueshifted absorption component. We fit it with narrow, broad, and absorption profiles. The rest of the lines, including [Ar iii] λ7138, Fe ii λ7156, and the [O ii] triplet (λλ7323, 7325, 7332), are modeled as independent narrow lines.\r\n\r\nHe i λ7065 shows a strong preference for an exponential profile (ΔBIC ∼ − 16) with a FWHM = 473 ± 116 km s−1. A residual bump spanning from ∼λ7290 to λ7320 is likely a combination of multiple Fe ii, such as λ7290, λ7308, and potentially Fe iii λ7319.65 lines. Curiously, the latter line is often labeled as “hazy” in various emission-line libraries (e.g., A. Kramida et al. 2024), reflecting its undefined shape as a result of pressure broadening or scattering in very dense gas.\r\n\r\n3.3.3. O i λ8448 and Iron Lines\r\nIn this part of the spectrum the O i λ8448 is fit with narrow and broad components. All of the iron lines, including Fe ii λλ8228, 8239, 8289, 8470, 8490 as well as a potential Fe iii λ8306, are fit as narrow lines with shared kinematics. O i components are fit independently.\r\n\r\nWe find that the broad O i component is best described by a standard Gaussian profile, with a stronger statistical preference over exponential wings (ΔBIC ∼ 4). However, we caution that a trough at ∼3.77 μm, likely an artifact, may affect the reliability of the fit in this region.\r\n\r\n3.3.4. Iron Forest and Paschen Lines\r\nThis spectral region is among the most complex, due to the dense clustering of emission features. The Paschen lines Pa10–Pa8 are modeled with narrow and broad components. To reduce the number of free parameters, we tie all narrow Paschen components together kinematically, and do the same for the broad components. Fe ii λλ9075, 9125, 9134,9179, 9204, 9394 are fit with a shared centroid and width. [S iii] lines are fit independently.\r\n\r\nThe [S iii] λ9071 line is used to define the systemic redshift: z = 3.50102 ± 0.00019. This is done because forbidden lines, such as [S iii] or [O iii], have lower critical densities that are incompatible with the dense-gas envelopes giving rise to the other lines we observe. These lines may instead come from the host galaxy itself (e.g., R. Maiolino et al. 2024), and we therefore choose this line to define the overall redshift of the system and to measure all the offsets relative to it. All velocity offsets discussed in the subsequent sections are computed relative to this reference frame. The Paschen lines show strong preference for exponential wings (ΔBIC ∼ −38), with a FWHM = 766 ± 202 km s−1—narrower than Hα, but consistent within 2σ.\r\n\r\n3.3.5. Paδ\r\nThe Fe ii λ9997 and Paδ complex is modeled with an independent narrow component for Fe ii and both narrow and broad components for Paδ. There is no evidence for absorption. Exponential wings are again preferred (ΔBIC ∼ −26). The resulting FWHM of 1672 ± 458 km s−1 is notably larger than those of both higher-order Paschen lines and Hα, though still consistent with the latter within 2σ. It is also possible that the line shape is impacted by Fe ii λ9997 and the undetected (but likely present) Fe ii λλ10131, 10173 lines.\r\n\r\n3.3.6. He i λ10830 and Paγ\r\nThe final window contains a complicated blend of broad He i λ10830 and Paγ lines, with a clear blueshifted absorption in the former. We fit three components (narrow, broad, and absorption) to He iλ10830 and narrow plus broad components to Paγ, keeping everything kinematically independent. We fit narrow Fe ii lines at 10490, 10501, and 11128 Å with fixed redshift and line width. Finally, O i λ11290 is fit with independent narrow and broad components. Exponential wings are again preferred over a pure Gaussian profile.\r\n\r\n4. Data Analysis\r\n4.1. Morphology\r\nLRDs are unresolved in the rest-optical by definition, with measured sizes consistent with the PSF HWHM ( in F444W), and in some cases even smaller when dithers align favorably (e.g., I. Labbé et al. 2025). Gravitational lensing can further push constraints on their intrinsic sizes to ≲100 pc (L. J. Furtak et al. 2024).\r\n\r\nIn the rest-UV, however, a more complex picture is emerging. Several studies have now reported faint, extended, asymmetric components adjacent to the compact core (V. Kokorev et al. 2024b; I. Labbe et al. 2024; J. Matthee et al. 2024; P. Rinaldi et al. 2025a, 2025b), often suppressed by surface-brightness dimming. As shown in Figure 1, GLIMPSE-17775 likewise consists of two components out to F200W (rest ∼ 4000 Å), coincident with the Balmer break. However, we note that the break itself is much weaker than found in objects with very similar spectra (e.g., B. Wang et al. 2024; see Figure 3). At longer wavelengths, a point-source (PS) morphology dominates, consistent with a black-hole-dominated core. To quantify this transition, we model the NIRCam imaging using PYSERSIC (I. Pasha & T. B. Miller2023) with a minimal configuration: a fixed-center PS plus a freely offset Sérsic profile. Normalizations, n, and reff are all allowed to vary, and uncertainties are drawn from the Markov Chain Monte Carlo posteriors (e.g., V. Kokorev et al. 2024a).\r\n\r\nZoom InZoom OutReset image size\r\nFigure 3. The diversity of Balmer breaks in LRDs. The black points show the HST and JWST GLIMPSE photometry of GLIMPSE-17775. The blue line shows best-fit EAZY SED fit to the photometry only, fixing the redshift to the zspec. The maroon line show the combined and photometry-corrected G395M spectrum. While the red color in F200W–F277W is partially influenced by a bright Hα line, the Balmer break between F150W and F200W is still prominent. We further show spectra of various other LRDs (I. Labbe et al. 2024; B. Wang et al. 2024; A. de Graaff et al. 2025b; R. P. Naidu et al. 2025; A. J. Taylor et al. 2025), all shifted to z = 3.501 and normalized at 5100 Å. Finally, we show HST (blue) and JWST (orange) filter transmission curves below.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nOur fits show that the host galaxy dominates up to λrest ∼ 4000 Å, where the host and nucleus contribute roughly equally, beyond which the PS prevails to λrest ∼ 1 μm. Because the NIRCam LW detector has ≳2× poorer resolution than the SW, a clean separation of host and nucleus in the rest-optical is impractical (see, e.g., K. E. Whalen et al. 2026). Fortunately, F200W lies at the transition where both the resolution and flux ratio are favorable, so we use that band to illustrate our galaxy/LRD decomposition. We illustrate this in Figure 4, which also shows the increasing PS fraction with wavelength, while acknowledging the uncertainties at longer wavelengths.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 4. Top: two-component Sérsic+point-source (PS) fit to the F200W morphology of GLIMPSE-17775. Panels show, from left to right, the data, best-fit model, model with the extended component removed, and residuals. Bottom: fractional PS contribution vs. rest-frame wavelength. Shaded regions mark SW (blue) and LW (red) detectors, where the lower resolution of LW filters hinders reliable two-component decomposition.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nAfter applying the lensing correction, we find that the extended component dominating the UV light has a radius of reff ∼ 1000 pc, whereas the actual compact LRD, dominant in the rest-optical, is fully consistent with the PSF and reff < 300 pc.\r\n\r\n4.2. Dust Attenuation\r\nThe ratio between observed emission-line fluxes is commonly used to estimate dust extinction. For LRDs, this has typically been achieved through the Balmer decrement, provided that multiple Balmer lines are available. In our case, only Hα is detected. While the Paschen series, of which five lines are observed, could, in principle, be used to estimate extinction, the likely presence of stratified dense gas in LRDs (A. de Graaff et al. 2025b; R. P. Naidu et al. 2025) implies that the intrinsic line ratios may deviate significantly from standard Case B recombination expectations (S.-J. Chang et al. 2026). Further, at the wavelengths of the Paschen series, the attenuation curves are practically flat (e.g., D. Calzetti et al. 2000). Small offsets of the Case B ratios would have a significant effect on the derived dust attenuation, but in return require extreme precision on measured line fluxes to be meaningful. Our uncertainties on, e.g., Paγ/Paδ are small, roughly 10%–15%, yet this still leads to an impractically high uncertainty on AV. To circumvent this limitation, we instead employ the ratio between the permitted O i λ8448 and O i λ11290 lines.\r\n\r\nThese transitions share a common energy level, and under the assumption of Bowen (Lyβ) fluorescence, all transitions through the λ11290 transition also cascade through the λ8448. This makes their intrinsic intensity set solely by the ratio of the inverse of their wavelengths.\r\n\r\nTo ensure we are comparing the same physical gas component, we isolate the narrow emission peaks in both transitions, which show consistent widths of FWHM ∼ 250 km s−1. This similarity supports the use of their flux ratio as a dust probe. We adopt the Small Magellanic Cloud (SMC) attenuation curve (K. D. Gordon et al. 2003), widely used for high-redshift galaxies and reddened AGN (P. F. Hopkins et al. 2004; P. L. Capak et al. 2015; N. A. Reddy et al. 2015, 2018; V. Kokorev et al. 2023; A. J. Taylor et al. 2025). Assuming an intrinsic ratio of (8448/11290)int = 1.336 (D. E. Osterbrock1989), we infer AV = 0.1 ± 0.3 mag, consistent with negligible extinction.\r\n\r\nWe caution, however, that this ratio probes only the narrow-line-emitting gas, which could originate either in the host galaxy or within a narrow-line region associated with the AGN. If the latter is the case, then the red optical continuum slope (βopt ∼ 0.35) would suggest that the observed SED is intrinsically red rather than reddened by dust. If instead the narrow lines arise predominantly in the host galaxy, this constraint does not directly inform the origin of the continuum emission. Similar Case B–consistent narrow-line ratios have been reported in other LRDs (e.g., M. Brooks et al. 2025; G. P. Nikopoulos et al. 2025), where the broad lines were found to show significant departures from Case B.\r\n\r\nAlthough the wavelength coverage of the red grating does not allow a Balmer decrement test for the broad-line emission (only Hα is detected), we can perform a consistency check using the brightest broad Paschen lines (Paγ, Paδ, and Pa8). Adopting intrinsic Case B ratios from P. J. Storey & D. G. Hummer (1995; Paγ/Paδ ≃ 1.5 and Paδ/Pa8 ≃ 1.8), and comparing these to our measured values of Paγ/Paδ = 1.77 ± 0.15 and Paδ/Pa8 = 1.94 ± 0.20, we find the broad Paschen lines to be consistent with Case B within ≃2σ, particularly when systematic uncertainties from blending and profile decomposition are taken into account. If Case B is applicable in the dense environments surrounding the central AGN, this would be consistent with a low-dust or dust-free origin for the broad-line-emitting gas.\r\n\r\n5. Line Properties\r\nOur fitting procedure yields over 40 emission and absorption features, most of which are detected at a high (S/N> 3) significance. With all the pieces in place, we now comment on the line profiles, kinematics, and the specific line species that we identify.\r\n\r\n5.1. Exponential Wings\r\nAs already noted throughout Section 4, and further highlighted in Figure 2, all permitted lines in the spectrum, with the exception of O iλ8448, which is likely impacted by data-quality issues, are better fit when the broad component is convolved with an exponential profile. The statistical preference for this model (as measured by ΔBIC) is especially strong for our brightest line, Hα. To further demonstrate this, and to compare this fit with a more standard, Gaussian-only approach, we show both models in Figure 5. When the broad line is fit using only a Gaussian profile, large portions of the line are underfit at a ≳3σ significance level, whereas a model that includes exponential wings shows a much smoother, albeit not perfect, residual plot.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 5. Exponential wings are required. Comparison of a Gaussian×exponential model (red) and a single Gaussian profile (blue) for Hα. Uncertainties are shown as vertical lines in each spectral bin, although they are too small to be visible. The exponential model provides a far superior fit, with smoother residuals and a strongly preferred ΔBIC, highlighting the necessity of exponential wings to capture the broad-line shape.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nThis strong preference for exponential wings is consistent with expectations from electron scattering in dense, ionized gas. Unlike Gaussian profiles, which arise from Doppler broadening due to thermal and bulk motions around the supermassive black hole, exponential profiles arise in environments dominated by electron scattering (e.g., S.-J. Chang et al. 2026; V. Rusakov et al. 2026). The absence of strong broadening in the forbidden lines (e.g., [S ii], [S iii], and [N ii]) already suggests that the densities where these electron-scattered profiles originate must already exceed multiple times the critical densities of these transitions (ne > 106). Combined with the fact that these broad profiles are non-Gaussian in shape, both the likely volume and column densities are likely even higher, at ne = 108 cm−3 and Ne ∼ 1024 cm−2, respectively, as suggested by both K. Inayoshi & R. Maiolino (2025) and V. Rusakov et al. (2026).\r\n\r\nRecent work (e.g., M. Brazzini et al. 2025) argues that, in classical broad-line region (BLR) environments, an electron-scattering origin for broad wings requires similar intrinsic and scattering widths across recombination lines. We therefore examine these criteria for the hydrogen transitions and find that, within the uncertainties of our fits, both the intrinsic and exponential widths are broadly comparable among the recombination lines. However, unlike classical BLRs, LRDs are expected to be strongly stratified, with different recombination transitions forming at different depths and probing different effective electron columns (e.g., A. de Graaff et al. 2025d; A. Sneppen et al. 2026). In such a structure, strict equality of widths is not expected even if a common scattering kernel shapes the wings. The modest variations observed here are therefore consistent with electron scattering in a dense, stratified cocoon.\r\n\r\nIt is important to note that such detailed profile decomposition is only possible due to the exceptionally high S/N per pixel achieved in the line wings of our NIRSpec G395M spectrum. As emphasized in V. Rusakov et al. (2026), these features would be impossible to distinguish with shallower data or lower-resolution modes such as NIRSpec/PRISM, or even G395M exposures lacking comparable depth.\r\n\r\n5.2. Line Profiles\r\nFurther, in Figure 6, we compare the best-fit models for all broad lines. As noted previously, with the exception of O i λ8448, every broad line is better described by exponential wings, resulting in very similar overall line shapes. The main differences arise in their widths.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 6. Best-fit profiles of all broad lines, oversampled and shifted to a common center. The top panel shows hydrogen recombination (Hα, black, and Paschen series), the middle panel shows O i, and the bottom panel shows He i. Shaded regions indicate 1σ uncertainties for the least-constrained lines (Paδ, O i λ11290, and He i λ6680); uncertainties for the remaining lines are omitted for clarity. We note that hydrogen and O i lines show largely similar widths, consistent with their coupling through charge exchange. By contrast, He i lines are systematically narrower, likely reflecting their distinct metastable triplet physics and formation in a less dense outer region.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nDespite some fits having sizable uncertainties, a trend emerges across line species. Hydrogen recombination lines (with the exception of Paδ) and O i transitions consistently show comparable intrinsic FWHM values of ∼800 km s−1. This agreement is not coincidental. Neutral oxygen and ionized hydrogen have nearly identical ionization potentials, enabling rapid charge-exchange coupling between O+ + H0⇌ O0 + H+ (D. E. Osterbrock & G. J. Ferland 2006). This continual electron exchange tightly locks the spatial distribution, ionization state, and kinematics of neutral oxygen to ionized hydrogen (and vice versa), so their broad-line profiles are naturally expected to track one another. The observed similarity therefore provides an important consistency check, reinforcing that the O i emission originates in the same dense, ionized gas as the hydrogen recombination lines. In contrast, the Fe ii lines exhibit significantly narrower widths, matching the narrow cores of the permitted transitions rather than their exponential wings. This implies that the Fe ii emission arises in a cooler, less turbulent zone exterior to the scattering-dominated region, but still closely coupled to the AGN continuum source.\r\n\r\nBy contrast, He i emission is systematically narrower. He i lines such as λ7065 and λ10830 do not couple to hydrogen via charge exchange, and their lower metastable level (23S) has distinct population physics, being fed by both collisional and recombination pathways. Further, one has to take into account the radiative-transfer effects, which make it possible to radiatively excite metastable ground-state electrons. As a result, He i emission may arise from a somewhat different spatial or kinematic region than H and O. We return to this point in more detail below.\r\n\r\nTaken together, the similar FWHM of hydrogen and oxygen broad-line profiles, combined with the near-universal exponential wings seen across all permitted transitions, strongly suggests that the line shapes are set by a common, line-independent scattering kernel rather than by transition-specific processes. Electron (Thomson) scattering in a dense, ionized cocoon provides a natural explanation: It produces exponential wings of nearly identical form across species, with widths set primarily by the electron temperature and column density (typically ∼1024 cm−2), and leaves only secondary variations from species-specific excitation or optical-depth effects (e.g., S.-J. Chang et al. 2026; V. Rusakov et al. 2026). In this framework, the narrower He i lines reflect stratification within the cocoon, where He i emission arises from an outer region that has a lower density, temperature, or column density, while the bulk hydrogen and oxygen emission share a common kinematic imprint within an inner, denser region.\r\n\r\n5.3. Line Kinematics\r\nBefore we proceed to discussing the individual features in more detail, we would like to comment on the systematic velocity offsets between various line species in the spectrum of GLIMPSE-17775. As mentioned previously, we choose the redshift of the narrow forbidden [S iii] λ9701 as the systemic reference, due to it being relatively bright and isolated. We place all velocity offsets in context by plotting all values from Tables 4 and 5 in Figure 7.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 7. Velocity offsets (relative to [S iii]λ9071) and FWHM for all detected lines. Narrow permitted lines are shown as maroon circles (open for forbidden), broad lines as blue, absorption as gold, and Fe ii lines as green diamonds. The shaded band marks the velocity uncertainty set by the median spectral resolution. Narrow lines align closely with the systemic redshift, while absorption features show moderate blueshifts of ∼150 km s−1.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nWhile every fit formally yields a centroid, the significance of any offset is constrained by the spectral resolution and S/N of the data. To gauge which velocity shifts are meaningful, we adopt a conservative uncertainty of ΔV ∼ med(R)/5, with R = λ/Δλ. This corresponds to ∼60 km s−1, below which offsets are unlikely to be statistically significant.\r\n\r\nQualitatively, we do not find systematic shifts of either permitted or forbidden narrow lines relative to the systemic redshift. Iron lines also appear consistent with the systemic velocity. In contrast, the permitted broad lines, together with their associated absorption components, show a consistent blueshift of order ∼100 km s−1.\r\n\r\nSuch blueshifts are commonly interpreted as signatures of outflowing gas in the BLR, where scattering and absorption occur preferentially along outflowing sight lines. In the context of GLIMPSE-17775, this modest but systematic offset strengthens the case for a stratified cocoon, while the narrow lines trace gas in the outer regions at systemic velocity, the BLR and absorbing layers appear to be participating in bulk outflows. Confirming the detailed velocity structure, however, will require higher-resolution follow-up with the NIRSpec H-gratings (e.g., A. Saldana-Lopez et al. 2025; A. Torralba et al. 2026).\r\n\r\n5.4. Hydrogen Absorption Lines\r\nAlthough no strong hydrogen absorption lines are explicitly detected, the Hα profile (Figure 2) shows a noticeable asymmetry, with suppressed flux on the blue side of the line. This feature is best modeled by a blueshifted (∼−200 km s−1) absorption component, as already noted in Section 4. Similar nonresonant absorption signatures (e.g., Balmer lines) are now routinely observed in LRDs across a wide range of redshifts (e.g., J. E. Greene et al. 2024; V. Kokorev et al. 2024b; I. Labbe et al. 2024; X. Lin et al. 2024; A. J. Taylor et al. 2025). The presence of such absorption implies high gas densities of order n ∼ 109 cm−3 (P. B. Hall 2007; K. Inayoshi & R. Maiolino 2025). Interestingly, only atoms in the n = 2 state appear significantly populated, as we detect no evidence for Paschen absorption in any of the five lines present in our spectrum. This is not an instrumental effect of the M-grating, as we clearly detect an absorption feature in He i λ10830 but not in the immediately adjacent Paγ. This indicates that the n = 3 state is comparatively underpopulated.\r\n\r\nAnother key manifestation of the same physical mechanism is the Balmer break, corresponding to the n = ∞ → n = 2 transition limit. A prominent break is common in many LRD spectra (D. J. Setton et al. 2025), though not ubiquitous (e.g., V. Kokorev et al. 2023; R. Tripodi et al. 2025). While our spectral coverage does not extend to the Balmer limit itself, we observe a discontinuity of ∼1 mag between the F200W and F150W filters. Due to the F200W coverage of the SED, this flux jump cannot be attributed to line boosting from Hβ and the [O iii] doublet. Adopting the break parameterization of R. P. Naidu et al. (2025), we use our best-fit SED and measure fν,4050Å/fν,3670Å = 2.02 ± 0.10. Although weaker than the extreme values (∼4–7) reported for LRDz9 (A. J. Taylor et al. 2025), MoM BH*-1 (R. P. Naidu et al. 2025), or “the Cliff” (A. de Graaff et al. 2025b), this value lies close to the maximum achievable by evolved stellar populations (I. Labbe et al. 2024; B. Wang et al. 2024). However, this measurement is based on the total (PS+host) photometry. Given that the UV continuum is spatially resolved, as we have shown in Section 4.1, host-galaxy contamination may dilute the intrinsic break strength of the central component. While uncertainties on the PS/host decomposition increase significantly toward the rest-optical, we find that using the PS-only photometry produces a noticeably sharper break, increasing the inferred strength by ∼30%–50% to fν,4050Å/fν,3670Å ≈ 2.6–3.0. Although this does not allow us to robustly conclude whether the intrinsic PS break reaches the most extreme BH*-type objects (A. de Graaff et al. 2025b; R. P. Naidu et al. 2025; A. J. Taylor et al. 2025), it suggests that the Balmer discontinuity becomes stronger once the host contribution is removed, consistent with recent findings that host light can suppress the apparent break amplitude (e.g., A. de Graaff et al. 2025d; W. Q. Sun et al. 2026).\r\n\r\nTaken together, the presence of asymmetry in the Hα profile, likely caused by blueshifted Balmer absorption, and a Balmer break adds to the evidence, complementing the exponential line wings, that the emission in GLIMPSE-17775 arises from a dense, ionized cocoon of gas. The lack of a detectable Paschen break is consistent with this picture, as high densities and optical depths result in Thomson scattering while also naturally washing out higher-order continuum edges (e.g., B. Wang et al. 2025). Assuming LTE, an extremely low ratio n3/n2 ≲ 0.01 corresponds to an electron temperature of Te ∼ 5000 K or below, consistent with the warm, partially ionized gas expected in dense LRD cocoons.\r\n\r\nWe also observe moderately prominent and extremely prominent blueshifted absorption, respectively, in He i λ7065 and He i λ10830. The mechanism for this is similar, but not identical to, the hydrogen lines. We also note the prominent blueshifted absorption seen in both He i λ7065 and He i λ10830. However, the physical mechanism driving these helium features differs fundamentally from that of the hydrogen lines; we return to this in the following section.\r\n\r\n5.5. Helium Lines\r\nBoth He i λ7065 and He i λ10830 show blueshifted (∼70−80 km s−1 from the narrow-line center) absorption components with widths of ∼600−700 km s−1. Unlike the Balmer series, helium transitions are resonantly scattered, so the arguments regarding n = 2 state abundances do not apply. Before addressing the absorption itself, it is useful to consider what the observed line strengths already tell us.\r\n\r\nIn the spectrum of GLIMPSE-17775, we detect three He i lines: λ6680, λ7065, and λ10830. These originate from different physical mechanisms. The λ6680 singlet line is produced via recombination or radiative pumping, and is only weakly dependent on density. By contrast, λ7065 and λ10830 belong to the triplet system (along with λ3889, not covered by G395M), where the lower level is populated due to its very long lifetime. Electrons in this “ground state” can be collisionally or radiatively excited into higher energies, and therefore the triplet-line strengths depend strongly on density and, to a lesser extent, temperature. As emphasized by D. A. Berg et al. (2026), He i λ10830 is the most sensitive density diagnostic among these transitions, followed by λ7065. The fact that both are much stronger than λ6680 indicates that the region where they form is very dense. The prominence of λ10830 in particular already points to a high-density environment with a temperature T ≳ 104 K. Further, the broad λ6680 line has a noticeably larger FWHM than the triplet lines but is consistent with hydrogen recombination lines, which again makes sense since both originate from the same mechanism.\r\n\r\nWhat about absorption? Its presence further reinforces this picture. The lower level (23S) of the triplet system is a metastable, long-lived state that effectively acts as a ground state in dense or partially ionized gas. As a result, photons from the 23P → 23S transition can be resonantly absorbed and reemitted many times, analogous to Lyα or Mg ii. This mechanism naturally produces strong absorption features when the He i column density is high. The fact that He i λ10830 not only dominates the helium spectrum in emission but also shows the deepest absorption in the entire spectrum provides compelling evidence for a dense, ionized cocoon of gas enshrouding GLIMPSE-17775.\r\n\r\n5.6. Oxygen Lines\r\nAbove, we noted that O i λ8446 and λ11290 share very similar profiles with the hydrogen recombination lines. This is naturally expected because neutral oxygen is tightly coupled to hydrogen via charge exchange, which rapidly equilibrates the O/H ionization states in dense gas. When charge exchange is fast (high nH), the O i/O ii ratio tracks the H i/H ii ratio, so the O i-emitting gas shares the same kinematics as the hydrogen recombination region (B. T. Draine 2011). The observed agreement in FWHM between H and O i lines is therefore an important consistency check that both species originate in the same dense, partially ionized phase.\r\n\r\nA second, independent clue of high gas density and radiation field intensity comes from the excitation mechanism. The O iλ8446–λ11287 pair is the classic signature of Lyβ (Bowen) fluorescence: Lyβ pumps O i from the ground state and the ensuing cascade preferentially populates the levels that emit at 1.129 μm, which then cascade down through the 8446 Å line. In this channel, the line emissivity scales with both the neutral oxygen (or equivalently neutral hydrogen, via charge exchange) column and the local Lyβ radiation field. Therefore, producing strong O i fluorescence requires both a very bright Lyβ source and a dense neutral (or partially ionized) cocoon.\r\n\r\nFurther, we do not detect (5σ upper limit <12/[10−20 erg s−1 cm−2]) any of the other permitted O iλ7774, λ7254, and λ7790 lines, and the [O i] λ6302/O i λ8446 ratio is weak. If collisional excitation or pure recombination dominated, these lines would be comparatively strong; their absence strongly favors Bowen fluorescence as the primary driver of the observed O i emission.\r\n\r\nFinally, the velocity structure adds a natural stratification: hydrogen recombination and O i (fluorescent, charge-exchange coupled) share similar widths and profiles, while He i lines are systematically narrower. Since He i triplet transitions emerge from a metastable 23S level (with distinct, density-sensitive population pathways and resonant transfer), they likely trace a kinematically distinct layer within the same cocoon.\r\n\r\n5.7. Lyα Fluorescence in Iron Lines\r\nPermitted iron emission, primarily Fe ii and Fe iii (e.g., I. Labbe et al. 2024; R. Tripodi et al. 2025; A. Torralba et al. 2026), but in some cases extending to highly ionized species such as Fe vii (E. Lambrides et al. 2025; M. Tang et al. 2025) and Fe x (L. J. Furtak et al. 2024), has become a recurring feature in LRD spectra. In GLIMPSE-17775, the spectrum is exceptionally rich in NIR iron lines; we identify 16 Fe ii and one Fe iii transition. Understanding the origin of this emission is key to interpreting the dense-gas environment in LRDs.\r\n\r\nThe physics of Fe ii emission has long been a challenge for BLR photoionization models (M. Joly 1993). Thick, high-column-density (∼1025 cm−2) gas at the edges of the accretion disk has been invoked as a potential source (M. Joly 1987; S. Collin-Souffrin et al. 1988), where the scattering and absorption of the hard X-ray photons ionize the gas. Similarly, this would also enhance the Balmer and Paschen line luminosities. Further, extensive theoretical work has shown that Lyα fluorescence is fundamental in reproducing the observed Fe ii strengths (T. A. A. Sigut & A. K. Pradhan 1998, 2003). Lyα pumping not only boosts the UV and optical Fe ii emission, but also predicts strong lines in the NIR.\r\n\r\nThis expectation aligns closely with our observations. In Figure 8, we compare our measured Fe ii flux ratios (normalized to Fe ii λ9075) against the Lyα-pumped model predictions of T. A. A. Sigut & A. K. Pradhan (2003). With the exception of Fe ii λ9179, affected by blending with Fe ii λ9204 and Pa9, we find remarkably good agreement across the suite of detected features. In particular, the dense forest of Fe ii transitions spanning λλ9000–9200 (center-right panel in Figure 2) is reproduced almost exactly by the theoretical spectrum (see Figure 11 in T. A. A. Sigut & A. K. Pradhan 2003). We overlay the T. A. A. Sigut & A. K. Pradhan (2003) model directly on our continuum-subtracted fit in Figure 8, demonstrating that the observed Fe ii emission is fully consistent with fluorescence in dense gas near the BLR. The implication is that the majority of the Fe ii emission in GLIMPSE-17775 arises through Lyα pumping, directly tracing an extremely dense medium, ionized by an extremely luminous source, likely an accreting black hole. Given that the Fe ii lines are somewhat narrower than other permitted features, it is likely that the emitting region is located farther from the BLR—something that has already been shown in a classic example of a narrow Fe ii emitter, I Zw 1 (R. J. Rudy et al. 2000; A. O. M. Marinello et al. 2016).\r\n\r\nZoom InZoom OutReset image size\r\nFigure 8. Lyα-pumped iron emission in GLIMPSE-17775. Left: observed Fe ii flux ratios (black points), normalized to Fe iiλ9075, compared with predictions from Lyα fluorescence models of T. A. A. Sigut & A. K. Pradhan (2003, blue). The close correspondence across ∼14 lines indicates a common excitation mechanism driven by Lyα pumping in dense, partially shielded gas. Right: zoom in on the λλ9000–9400 complex, showing the remarkable agreement between the modeled continuum-subtracted Fe ii spectrum (black) and the T. A. A. Sigut & A. K. Pradhan (2003) model (blue). We show air wavelengths of each Fe ii line directly from T. A. A. Sigut & A. K. Pradhan (2003), including the blended features. Together, these comparisons support an origin in the dense inner regions of the cocoon surrounding the accreting black hole.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nTogether with the Balmer absorption, helium triplet features, and Bowen fluorescence in O i, the iron forest adds another piece of evidence that points to a dense cocoon enshrouding the black hole.\r\n\r\n5.8. Source Properties\r\nBased on the previous discussion, we now present the likely physical properties of the black hole and its host. The coexistence of broad permitted and narrow forbidden lines indicates, as in most LRDs (R. E. Hviding et al. 2025), that the broad components originate in an AGN BLR. Following J. E. Greene & L. C. Ho (2005), we derive MBH from the luminosity and width of the broad Hα line, assuming the exponential-wing profile demonstrated in Figures 2 and 5. With a FWHMHα = 1024 ± 21 km s−1, negligible dust, and μ = 2.04, we obtain , where the dominant uncertainty arises from the J. E. Greene & L. C. Ho (2005) calibration. A purely Gaussian fit, though statistically disfavored, would yield a FWHM 3 times larger and a black hole mass nearly a dex higher. Throughout this work, we adopt the MBH from the exponential model.\r\n\r\nFurther, by assuming that the bolometric luminosity (Lbol) scales as Lbol = 130 × LHα (G. T. Richards et al. 2006), we find Lbol = (1.06 ± 0.14) × 1045 erg s–1. Using our MBH derived by assuming exponential wings, we find that this object is accreting at a super-Eddington rate, Lbol/Ledd = 1.86 ± 0.25. This is higher than the vast majority of LRDs at all redshifts (e.g., V. Kokorev et al. 2023; L. J. Furtak et al. 2024; I. Juodžbalis et al. 2024; R. Maiolino et al. 2024; H. B. Akins et al. 2025b; D. D. Kocevski et al. 2025; A. J. Taylor et al. 2025), found to accrete at sub-Eddington rates. However, recent works examining LRDs with extreme Balmer breaks derive accretion rates that exceed the Eddington limit (E. Lambrides et al. 2024; A. de Graaff et al. 2025b; R. P. Naidu et al. 2025).\r\n\r\nA recent work examining multiwavelength LRD data suggests that the bolometric luminosity emerges predominantly from the rest-frame optical, with X-ray and radio contributions being largely subdominant (J. E. Greene et al. 2026). Given the suggested dominance of optical light in LRDs, the much lower bolometric corrections (×7–10 lower) would imply lower black hole masses and total bolometric luminosities (e.g., those derived from Hα) than standard AGN prescriptions (e.g., J. E. Greene & L. C. Ho 2005) might suggest. This adjustment would lower both the inferred black hole masses and bolometric luminosities. Because these two quantities scale together, the implied super-Eddington nature of GLIMPSE-17775 would remain unchanged, although the black hole mass could decrease to ∼105.5–105.8M⊙. This interpretation is consistent with dense-gas (BH*) models, which generically predict Eddington or super-Eddington accretion in heavily obscured environments (e.g., D. Kido et al. 2025; H. Liu et al. 2025; A. Sneppen et al. 2026). A more detailed reassessment of bolometric corrections for LRDs is clearly warranted, but such an analysis lies beyond the scope of this work. For consistency with previous studies, we adopt standard AGN bolometric corrections throughout, with all derived parameters listed in Table 1.\r\n\r\nFinally, we estimate an upper limit on the stellar mass in GLIMPSE-17775. Previous studies have modeled LRDs using joint galaxy+AGN SED decomposition (e.g., V. Kokorev et al. 2023; L. J. Furtak et al. 2024), and more recently, within the BH* framework, have assumed that most of the rest-UV flux arises from the host galaxy (R. P. Naidu et al. 2025; A. J. Taylor et al. 2025). Our spatial decomposition (Figure 4) supports this assumption: The extended component contributes >80% of the rest-UV light, implying that the bulk of the stellar mass resides in this resolved structure. Given this, we adopt a simple empirical approach using the MUV–M* relation (e.g., D. P. Stark et al. 2009; I. Labbé et al. 2013) and obtain a conservative upper limit on the stellar mass of M* ≲ 107.5M⊙. This in turn gives us a black hole-to-host mass ratio of ≲0.14, which is significantly elevated from local expectations (J. E. Greene & L. C. Ho 2005), but is not as extreme as some other LRDs reported in the literature (V. Kokorev et al. 2023; L. J. Furtak et al. 2024; R. Maiolino et al. 2024).\r\n\r\n6. Discussion and Summary\r\n6.1. Dense and Ionized Gas Surrounding the AGN\r\nOur NIRSpec G395M observations of GLIMPSE-17775 reveal a remarkably consistent picture: Across independent tracers, the line emission requires an environment of extremely high density and partial ionization.\r\n\r\nFirst, the broad permitted lines are universally better fit by exponential wings, a hallmark of electron scattering in gas with ne ≳ 108 cm−3 and column densities approaching Ne ∼ 1024 cm−2. Such profiles are not reproduced by Doppler broadening alone and point to an ionized scattering medium enveloping the source. The fact that hydrogen and O i lines share consistent FWHM values further anchors this interpretation, as charge exchange tightly couples neutral oxygen to the ionization and kinematics of hydrogen.\r\n\r\nSecond, the detection of blueshifted Balmer absorption and a significant Balmer break both require high n = 2 populations and densities n ∼ 109 cm−3. Helium transitions provide a complementary view: The triplet lines λ7065 and λ10830 are both strongly enhanced relative to the singlet states and show deep blueshifted absorption, consistent with resonant scattering from the metastable 23S level. Their systematically narrower widths compared to hydrogen and oxygen suggest stratification, with helium arising from denser, more compact layers of the cocoon.\r\n\r\nThird, the O i λ8446–λ11290 pair confirms Lyβ fluorescence, requiring both a bright Lyβ radiation field and a dense reservoir of neutral gas. The absence of other permitted O i lines not fed by Lyβ strengthens this conclusion. Finally, the detection of 16 Fe ii lines, forming an incredibly rich iron forest in this LRD, matches predictions from Lyα fluorescence models, again demanding an intense radiation field and very high densities.\r\n\r\nBecause the BLR is unresolved in essentially all AGN, broad-line widths are traditionally interpreted as virial tracers of the black hole potential. In GLIMPSE-17775, the virial story alone is insufficient: The issue is not how broad the lines are, but how they broaden. The profiles exhibit extended, nearly linear wings in velocity space that are incompatible with a Gaussian. Instead, the lines are systematically and significantly better described by a model consisting of a narrow Gaussian core (virial motion) plus exponential wings, the hallmark of Thomson scattering in a dense ionized medium. Thus, the line shape encodes both gravitational kinematics and radiative-transfer physics in the surrounding cocoon. Our schematic (Figure 9) summarizes this revised view: In LRDs, broad-line profiles are not set by dynamics alone, but by the scattering environment through which the photons escape.\r\n\r\nZoom InZoom OutReset image size\r\nFigure 9. Physical picture of the dense cocoon around GLIMPSE-17775. The inner region (1) corresponds to the dense, highly ionized broad-line region (BLR) where electron scattering (orange lines) produces exponential wings, H and O I share coupled kinematics (via charge exchange and Bowen fluorescence), and strong Balmer absorption/break signatures arise. The outer layer (2) represents an intermediate-density ionized medium, where He I triplet lines show resonant absorption from the metastable 23S level and Fe II emission is driven by Lyα fluorescence. Together, these zones form a stratified cocoon enshrouding the accreting black hole. The bottom-right panel shows stacked line profiles of H, O i, He i, and Fe ii.\r\n\r\nDownload figure:\r\n\r\nStandard imageHigh-resolution image\r\nSuch conditions—high optical depths, large column densities, and evidence for radiation-dominated gas—are precisely those expected in super-Eddington accretion flows. In this regime, radiation pressure inflates the inner accretion structure, driving powerful winds and forming the very dense, partially ionized envelope we infer here. The low X-ray luminosities and weak radio emission commonly observed in LRDs (e.g., T. T. Ananna et al. 2024; M. Yue et al. 2024; H. B. Akins et al. 2025a; M. Kokubo & Y. Harikane 2025) are consistent with this picture: The X-rays are likely absorbed or thermalized within the optically thick cocoon, while dust cannot survive in such an intense radiation field (e.g., E. Lambrides et al. 2024; A. de Graaff et al. 2025b; K. Inayoshi & R. Maiolino 2025; R. P. Naidu et al. 2025; A. J. Taylor et al. 2025). Thus, the spectroscopic signatures observed in GLIMPSE-17775—exponential wings, absorption features, and fluorescence-driven metal lines—fit naturally into a scenario where super-Eddington accretion onto a low-mass black hole powers the luminous yet heavily reprocessed emission.\r\n\r\nTaken together, the exponential wings, Balmer and helium absorption, Bowen oxygen lines, and Lyα-pumped iron forest all converge on the same physical picture: GLIMPSE-17775 is enshrouded in a dense, partially ionized cocoon of gas.\r\n\r\n6.2. Final Remarks\r\nUsing a combination of the intrinsically deepest NIRCam photometry and NIRSpec G395M observations of the lensed AS1063 field, we present a detailed investigation of a LRD at z = 3.501. The spectrum of GLIMPSE-17775 is exceptionally rich, with more than 40 detected features, allowing us to probe the physical conditions of the gas with unprecedented detail. Multiple independent diagnostics converge on the presence of a dense, partially ionized cocoon heated by a powerful ionizing source.\r\n\r\nTypical of other LRDs, GLIMPSE-17775 is extremely compact in the rest-optical (reff < 300 pc) but exhibits more extended structure in the rest-UV (reff ∼ 1000 pc; Figure 1). It shows unmistakable AGN signatures through broad permitted lines (e.g., D. D. Kocevski et al. 2023; V. Kokorev et al. 2023; J. E. Greene et al. 2024; L. J. Furtak et al. 2024). The uniquely deep G395M spectrum further reveals clues to the physical origin of both its continuum and line-emission properties: We detect exponential broad-line wings, Balmer and helium absorption, Bowen-pumped O i, Fe ii emission produced by Lyα fluorescence, and evidence for rapid, potentially super-Eddington growth.\r\n\r\nTogether, these diagnostics provide one of the clearest cases yet for the BH* “dense cocoon” scenario (A. de Graaff et al. 2025b; K. Inayoshi & R. Maiolino 2025; R. P. Naidu et al. 2025; A. J. Taylor et al. 2025). The same ingredients we observe—exponential broad wings, Balmer-break absorption, He i absorption, and rich Fe ii and O i fluorescence—have been detected individually in several other bright LRDs with medium- and high-resolution spectroscopy (e.g., L. J. Furtak et al. 2024; I. Juodžbalis et al. 2024; I. Labbe et al. 2024; F. D’Eugenio et al. 2025; E. Lambrides et al. 2025; B. Wang et al. 2025; A. Torralba et al. 2026), suggesting that dense, optically thick gas may be a common feature of the population rather than an anomaly. What distinguishes GLIMPSE-17775 is that all signatures are captured simultaneously and at high S/N, allowing a self-consistent physical interpretation. If such cocoons are widespread, then super-Eddington accretion may be a typical pathway for black hole growth in LRDs, especially among the most luminous systems. Establishing how these signatures vary with luminosity and redshift will be essential for determining whether dense cocoons represent a dominant mode of early black hole assembly.\r\n\r\nThe convergence of five independent diagnostics—exponential scattering wings, Balmer-limit absorption, helium triplet physics, and two distinct fluorescence channels—leaves little doubt: GLIMPSE-17775 hosts a dense (n ∼ 108−9 cm−3), optically thick (Ne ∼ 1024 cm−2) cocoon of partially ionized gas surrounding a super-Eddington accreting black hole. This represents some of the most direct and comprehensive spectroscopic evidence to date for the dense cocoon scenario in LRDs.\r\n\r\nAcknowledgments\r\nThe authors would like to thank Aaron Sigut and Anil Pradhan for their help with understanding iron emission in active galactic nuclei. The authors would like to acknowledge the National Institute of Standards and Technology (NIST) database of spectral lines (A. Kramida et al. 2024), which made identification of less-known emission features possible. V.K., J.C., S.F., D.B., L.F., T.H., and J.M. acknowledge support from the University of Texas at Austin Cosmic Frontier Center. A.Z. acknowledges support by the Israel Science Foundation grant No. 864/23. This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-03127. The JWST data presented in this article were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The specific observations analyzed can be accessed via doi:10.17909/4byn-fe55 and doi:10.17909/zq0c-8t87. These observations are associated with programs GO #3293 and DDT #9223.\r\n\r\nFacilities: JWST - James Webb Space Telescope, HST - Hubble Space Telescope satellite.\r\n\r\nSoftware: EAZY (G. B. Brammer et al. 2008), grizli (G. Brammer 2023), msaexp (G. Brammer 2022), photutils (L. Bradley et al. 2020), pysersic (I. Pasha & T. B. Miller 2023), sep (K. Barbary 2016), SExtractor (E. Bertin & S. Arnouts1996).","issue":"2","citation":{"short":"V. Kokorev, J. Chisholm, R.P. Naidu, S. Fujimoto, H. Atek, G. Brammer, S.L. Finkelstein, H.B. Akins, D.A. Berg, L.J. Furtak, Q. Fei, T.Y.-Y. Hsiao, I. Labbé, J.J. Matthee, J.B. Muñoz, P.A. Oesch, R. Pan, P. Rinaldi, A. Saldana-Lopez, D. Schaerer, M. Volonteri, A. Zitrin, The Astrophysical Journal 1004 (2026).","ieee":"V. Kokorev et al., “The Deepest GLIMPSE of a dense gas cocoon enshrouding a Little Red Dot,” The Astrophysical Journal, vol. 1004, no. 2. IOP Publishing, 2026.","apa":"Kokorev, V., Chisholm, J., Naidu, R. P., Fujimoto, S., Atek, H., Brammer, G., … Zitrin, A. (2026). The Deepest GLIMPSE of a dense gas cocoon enshrouding a Little Red Dot. The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae4ed7","mla":"Kokorev, Vasily, et al. “The Deepest GLIMPSE of a Dense Gas Cocoon Enshrouding a Little Red Dot.” The Astrophysical Journal, vol. 1004, no. 2, 153, IOP Publishing, 2026, doi:10.3847/1538-4357/ae4ed7.","ista":"Kokorev V, Chisholm J, Naidu RP, Fujimoto S, Atek H, Brammer G, Finkelstein SL, Akins HB, Berg DA, Furtak LJ, Fei Q, Hsiao TY-Y, Labbé I, Matthee JJ, Muñoz JB, Oesch PA, Pan R, Rinaldi P, Saldana-Lopez A, Schaerer D, Volonteri M, Zitrin A. 2026. The Deepest GLIMPSE of a dense gas cocoon enshrouding a Little Red Dot. The Astrophysical Journal. 1004(2), 153.","ama":"Kokorev V, Chisholm J, Naidu RP, et al. The Deepest GLIMPSE of a dense gas cocoon enshrouding a Little Red Dot. The Astrophysical Journal. 2026;1004(2). doi:10.3847/1538-4357/ae4ed7","chicago":"Kokorev, Vasily, John Chisholm, Rohan P. Naidu, Seiji Fujimoto, Hakim Atek, Gabriel Brammer, Steven L. Finkelstein, et al. “The Deepest GLIMPSE of a Dense Gas Cocoon Enshrouding a Little Red Dot.” The Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae4ed7."},"external_id":{"arxiv":["2511.07515"]},"arxiv":1,"quality_controlled":"1","intvolume":" 1004","language":[{"iso":"eng"}],"date_created":"2026-07-13T09:48:38Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa_version":"Published Version","date_published":"2026-06-10T00:00:00Z","researchdata_availability":"no","type":"journal_article","dataavailabilitystatement":"The specific observations analyzed can be accessed via doi:10.17909/4byn-fe55 and doi:10.17909/zq0c-8t87. These observations are associated with programs GO #3293 and DDT #9223.\r\n\r\nFacilities: JWST - James Webb Space Telescope, HST - Hubble Space Telescope satellite.\r\n\r\nSoftware: EAZY (G. B. Brammer et al. 2008), grizli (G. Brammer 2023), msaexp (G. Brammer 2022), photutils (L. Bradley et al. 2020), pysersic (I. Pasha & T. B. Miller 2023), sep (K. Barbary 2016), SExtractor (E. Bertin & S. 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