@article{20934, abstract = { Supervised learning for causal discovery from observational data often achieves competitive performance despite seemingly avoiding the explicit assumptions that traditional methods require for identifiability. In this work, we analyze CSIvA (Ke et al., 2023) on bivariate causal models, a transformer architecture for amortized inference promising to train on synthetic data and transfer to real ones. First, we bridge the gap with identifiability theory, showing that the training distribution implicitly defines a prior on the causal model of the test observations: consistent with classical approaches, good performance is achieved when we have a good prior on the test data, and the underlying model is identifiable. Second, we find that CSIvA can not generalize to classes of causal models unseen during training: to overcome this limitation, we theoretically and empirically analyze \textit{when} training CSIvA on datasets generated by multiple identifiable causal models with different structural assumptions improves its generalization at test time. Overall, we find that amortized causal discovery still adheres to identifiability theory, violating the previous hypothesis from Lopez-Paz et al. (2015) that supervised learning methods could overcome its restrictions.}, author = {Montagna, Francesco and Cairney-Leeming, Maximilian T and Sridhar, Dhanya and Locatello, Francesco}, issn = {2835-8856}, journal = {Transactions on Machine Learning Research}, publisher = {ML Research Press}, title = {{Demystifying amortized causal discovery with transformers}}, year = {2025}, } @article{20935, abstract = {In situ cryo-electron tomography (cryo-ET) has emerged as the method of choice to investigate the structures of biomolecules in their native context. However, challenges remain for the efficient production and sharing of large-scale cryo-ET datasets. Here, we combined cryogenic plasma-based focused ion beam (cryo-PFIB) milling with recent advances in cryo-ET acquisition and processing to generate a dataset of 1,829 annotated tomograms of the green alga Chlamydomonas reinhardtii, which we provide as a community resource to drive method development and inspire biological discovery. To assay data quality, we performed subtomogram averaging of both soluble and membrane-bound complexes ranging in size from >3 MDa to ∼200 kDa, including 80S ribosomes, Rubisco, nucleosomes, microtubules, clathrin, photosystem II, and mitochondrial ATP synthase. The majority of these density maps reached sub-nanometer resolution, demonstrating the potential of this C. reinhardtii dataset as well as the promise of modern cryo-ET workflows and open data sharing to empower visual proteomics.}, author = {Kelley, Ron and Khavnekar, Sagar and Righetto, Ricardo D. and Heebner, Jessica and Obr, Martin and Zhang, Xianjun and Chakraborty, Saikat and Tagiltsev, Grigory and Michael, Alicia and Van Dorst, Sofie and Waltz, Florent and Mccafferty, Caitlyn L. and Lamm, Lorenz and Zufferey, Simon and Van Der Stappen, Philippe and Van Den Hoek, Hugo and Wietrzynski, Wojciech and Harar, Pavol and Wan, William and Briggs, John A.G. and Plitzko, Jürgen M. and Engel, Benjamin D. and Kotecha, Abhay}, issn = {1097-4164}, journal = {Molecular Cell}, publisher = {Elsevier}, title = {{Toward community-driven visual proteomics with large-scale cryo-electron tomography of Chlamydomonas reinhardtii}}, doi = {10.1016/j.molcel.2025.11.029}, year = {2025}, } @misc{20936, abstract = {Supplementary material for Mombarg et al. (2025, A&A). Title: "Is a 1D perturbative method sufficient for asteroseismic modelling of ~Cephei pulsators? Implications for measurements of rotation and internal magnetic fields" Content: - Non-rotating ESTER models and associated .GSM models. (Xini = 0.71, Zini = 0.014, vertical/horizonal viscosity 10^7 cm^2/s, vertical chemical diffusion 10^4 cm^2/s for evolution model. More details on the ESTER models can be found in the ESTER manual. - Rotational asymmetries computed with StORM and TOP in 1/d, and the central m=0 frequency from TOP in 1/d. (all_A*_new.pkl) - Magnetic asymmetries in 1/d for different obliquity angles between 0 and 90 deg for ZAMS and MAMS model, for B_0 = 75 kG. *_nu key gives unperturbed mode frequencies, *_npg the radial order (asym_dict.pkl, asym_dict_evol.pkl)}, author = {Mombarg, Joey and Vanlaer, Vincent and Das, Srijan B and Rieutord, Michel and Aerts, Conny and Bugnet, Lisa Annabelle and Mathis, Stephane and Reese, Daniel and Ballot, Jerome}, publisher = {Zenodo}, title = {{Is a 1D perturbative method sufficient for asteroseismic modelling of β Cephei pulsators?}}, doi = {10.5281/ZENODO.17580178}, year = {2025}, } @misc{20940, abstract = {These are the raw data files that supplement our study of mode dispersion with magnetic field of a cavity-magnonics system containing chromium trichloride on coplanar waveguide resonator.}, author = {Mandal, Supriya and Maji, Krishnendu and Kapoor, Lucky and Sasmal, Souvik and Manni, Soham and Jesudasan, John and Raychaudhuri, Pratap and Thamizhavel, Arumugam and Deshmukh, Mandar M.}, publisher = {Zenodo}, title = {{Mode dispersion with magnetic field in a cavity-magnonics system}}, doi = {10.5281/ZENODO.15321721}, year = {2025}, } @article{20960, abstract = {A linker unit was designed and synthesized that can serve both as a hairpin turn in a DNA duplex and anchor point for an aromatic helical foldamer mimicking the shape and surface properties of B‐DNA. Methods were developed to synthesize natural/non‐natural chimeric molecules combining foldamer and DNA segments. The ability of the linker to position the foldamer helix and the duplex DNA so that their rims and grooves are in register, despite their completely different chemical nature, was demonstrated using single crystal X‐ray diffraction, circular dichroism and molecular models. Bio‐layer interferometry confirmed that artificial hairpin DNA duplexes keep their ability to bind to DNA binding proteins. The chimeric molecules may pave the way to competitive inhibitors of protein‐DNA interactions involving sequence‐selective DNA‐binding proteins.}, author = {Loos, Manuel and Xu, Felix and Mandal, Pradeep K and Chakrabortty, Tulika and Douat, Céline and Konrad, David B. and Cabbar, Melis and Singer, Johannes and Corvaglia, Valentina and Carell, Thomas and Huc, Ivan}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, number = {31}, publisher = {Wiley}, title = {{Interfacing B‐DNA and DNA mimic foldamers}}, doi = {10.1002/anie.202505273}, volume = {64}, year = {2025}, } @article{20973, abstract = {CuAgSe-based materials are attractive for low-temperature thermoelectric (TE) applications but are limited by bipolar conduction and relatively high thermal conductivity. Herein, we report a ligand-free aqueous synthesis of Te-doped CuAgSe (CuAgSe1-xTex), where structural and electronic modulation improve carrier transport and suppress phonon propagation. Ex-situ time-resolved X-ray diffraction reveals a spontaneous growth mechanism, while density functional theory calculations show that Te-5s and 5p orbitals hybridization generates localized states and an asymmetric density of states, thereby enhancing the Seebeck coefficient. Electron microscopy and strain analyses confirm that Te-doping introduces a high density of lattice dislocations and grain boundaries, leading to a reduced lattice thermal conductivity of 0.11 W m−1K−1 at 443 K. These synergistic effects translate into device-level performance—the first integrated CuAgSe thermoelectric modules, exhibit a maximum cooling temperature difference of 27.3 K, and power density of 0.34 W cm−2 with a conversion efficiency of 3.6% at a modest temperature gradient of 136 K. These results demonstrate that CuAgSe1-xTex enables efficient energy harvesting and localized cooling under small temperature gradient, underscoring the importance of structural and electronic design beyond conventional zT benchmarks.}, author = {Meng, Weite and Li, Mingquan and Wang, Qingyue and Song, Pingan and Yang, Xuan and Wang, Wen Jun and Hong, Min and Ibáñez, Maria and Cabot, Andreu and Zhang, Yu and Liu, Yu and Lim, Khak Ho}, issn = {1613-6829}, journal = {Small}, publisher = {Wiley}, title = {{Efficient near room temperature thermoelectric cooling and power generation with CuAgSe}}, doi = {10.1002/smll.202513035}, year = {2025}, } @article{20976, abstract = {We present an experimental demonstration of an impedance-engineered Josephson parametric amplifier (IEJPA) fabricated in a single-step lithography process. Impedance-engineering is implemented using a lumped-element series LC circuit. We use a simpler lithography process where the entire device—impedance transformer and Josephson parametric amplifier (JPA)—is patterned in a single electron beam lithography step, followed by a double-angle Dolan-bridge technique for Al–AlOx–Al deposition. We observe amplification with 18 dB gain over a wide 400 MHz bandwidth centered around 5.3 GHz with added noise approaching the quantum limit, and a saturation power of −114 dBm. To accurately explain our experimental results, we extend existing theories for IEJPAs to incorporate the full sine nonlinearity of both the JPA and the transformer. Our work provides a route to simpler realization of broadband JPAs and a theoretical foundation for a regime of JPA operation that has been less explored in literature.}, author = {Patel, Lipi and Hawaldar, Samarth and Panikkar, Aditya and Shankar, Athreya and Suri, Baladitya}, issn = {1077-3118}, journal = {Applied Physics Letters}, number = {25}, publisher = {AIP Publishing}, title = {{Impedance-engineered Josephson parametric amplifier with single-step lithography}}, doi = {10.1063/5.0290636}, volume = {127}, year = {2025}, } @article{20977, abstract = {Hippocampal sharp-wave ripples (SPW-Rs) are high-frequency oscillations critical for memory consolidation. Despite extensive characterization in rodents, their detection in humans is limited by coarse spatial sampling, interictal epileptiform discharges (IEDs), and a lack of consensus on human ripple localization and morphology. Here, we demonstrate that mouse and human hippocampal ripples share spatial, spectral and temporal features, which are clearly distinct from IEDs. In recordings from male APP/PS1 mice, SPW-Rs were distinguishable from IEDs by multiple criteria. Hippocampal ripples recorded during NREM sleep in female and male surgical epilepsy patients exhibited similar narrowband frequency peaks and multiple ripple cycles in the CA1 and subiculum regions. Conversely, IEDs showed a broad spatial extent and wide-band frequency power. We developed a semi-automated, ripple curation toolbox (ripmap) to separate event waveforms by low-dimensional embedding to reduce false-positive rate in selected ripple channels. Our approach improves ripple detection and provides a firm foundation for future human memory research.}, author = {Maslarova, Anna and Shin, Jiyun N. and Navas Olivé, Andrea C and Vöröslakos, Mihály and Hamer, Hajo and Doerfler, Arnd and Henin, Simon and Buzsáki, György and Liu, Anli}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Spatiotemporal patterns differentiate hippocampal sharp-wave ripples from interictal epileptiform discharges in mice and humans}}, doi = {10.1038/s41467-025-66562-6}, volume = {16}, year = {2025}, } @article{20990, abstract = {Modeling the response of material and chemical systems to electric fields remains a longstanding challenge. Machine learning interatomic potentials (MLIPs) offer an efficient and scalable alternative to quantum mechanical methods, but do not by themselves incorporate electrical response. Here, we show that polarization and Born effective charge (BEC) tensors can be directly extracted from long-range MLIPs within the Latent Ewald Summation (LES) framework, solely by learning from energy and force data. Using this approach, we predict the infrared spectra of bulk water under zero or finite external electric fields, ionic conductivities of high-pressure superionic ice, and the phase transition and hysteresis in ferroelectric PbTiO3 perovskite. This work thus extends the capability of MLIPs to predict electrical response –without training on charges or polarization or BECs– and enables accurate modeling of electric-field-driven processes in diverse systems at scale.}, author = {Zhong, Peichen and Kim, Dongjin and King, Daniel S. and Cheng, Bingqing}, issn = {2057-3960}, journal = {npj Computational Materials}, publisher = {Springer Nature}, title = {{Machine learning interatomic potential can infer electrical response}}, doi = {10.1038/s41524-025-01911-z}, volume = {11}, year = {2025}, } @article{21003, abstract = {We extend work of Heath-Brown and Salberger, based on the determinant method, to provide a uniform upper bound for the number of integral points of bounded height on an affine surface, which are subject to a polynomial congruence condition. This is applied to get a new uniform bound for points on diagonal quadric surfaces, and to a problem about the representation of integers as a sum of four unlike powers.}, author = {Browning, Timothy D and Verzobio, Matteo}, issn = {2397-3129}, journal = {Discrete Analysis}, publisher = {Cambridge: Alliance of Diamond Open Access Journals}, title = {{Counting integer points on affine surfaces with a side condition}}, doi = {10.19086/da.143787}, volume = {2025}, year = {2025}, } @article{21007, abstract = {Currently, the best known tradeoff between approximation ratio and complexity for the Sparsest Cut problem is achieved by the algorithm in [Sherman, FOCS 2009]: it computes O(√(log n)/ε)-approximation using O(nε logO(1) n) maxflows for any ε∈[Θ(1/log n),Θ(1)]. It works by solving the SDP relaxation of [Arora-Rao-Vazirani, STOC 2004] using the Multiplicative Weights Update algorithm (MW) of [Arora-Kale, JACM 2016]. To implement one MW step, Sherman approximately solves a multicommodity flow problem using another application of MW. Nested MW steps are solved via a certain "chaining" algorithm that combines results of multiple calls to the maxflow algorithm. We present an alternative approach that avoids solving the multicommodity flow problem and instead computes "violating paths". This simplifies Sherman's algorithm by removing a need for a nested application of MW, and also allows parallelization: we show how to compute O(√(log n)/ε)-approximation via O(logO(1) n) maxflows using O(nε) processors. We also revisit Sherman's chaining algorithm, and present a simpler version together with a new analysis.}, author = {Kolmogorov, Vladimir}, issn = {1549-6333}, journal = {ACM Transactions on Algorithms}, number = {4}, pages = {1--22}, publisher = {Association for Computing Machinery}, title = {{A simpler and parallelizable O(√log n)-approximation algorithm for SPARSEST CUT}}, doi = {10.1145/3748723}, volume = {21}, year = {2025}, } @unpublished{21016, abstract = {Motivated by applications in chemistry, we give a homlogical definition of tunnels, or more generally cobordisms, connecting disjoint parts of a cell complex. For a filtered complex, this defines a persistence module. We give a method for identifying birth and death times using kernel persistence and a matrix reduction algorithm for pairing birth and death times.}, author = {Bleile, Yossi and Fajstrup, Lisbeth and Heiss, Teresa and Svane, Anne Marie and Sørensen, Søren Strandskov}, booktitle = {arXiv}, title = {{Identifying cobordisms using kernel persistence}}, doi = {10.48550/arXiv.2505.17858}, year = {2025}, } @article{21017, abstract = {With the growing interest in blockchains, permissioned approaches to consensus have received increasing attention. Unfortunately, the BFT consensus algorithms that are the backbone of most of these blockchains scale poorly and offer limited throughput. In fact, many state-of-the-art BFT consensus algorithms require a single leader process to receive and validate votes from a quorum of processes and then broadcast the result, which is inherently non-scalable. Recent approaches avoid this bottleneck by using dissemination/aggregation trees to propagate values and collect and validate votes. However, the use of trees increases the round latency, which limits the throughput for deeper trees. In this paper we propose Kauri, a BFT communication abstraction that sustains high throughput as the system size grows by leveraging a novel pipelining technique to perform scalable dissemination and aggregation on trees. Furthermore, when the number of faults is moderate (arguably the most common case in practice), our construction is able to recover from faults in an optimal number of reconfiguration steps. We implemented and experimentally evaluated Kauri with up to 800 processes. Our results show that Kauri outperforms the throughput of state-of-the-art permissioned blockchain protocols, by up to 58x without compromising latency. Interestingly, in some cases, the parallelization provided by Kauri can also decrease the latency.}, author = {Neiheiser, Ray and Matos, Miguel and Rodrigues, Luis}, issn = {1557-7333}, journal = {ACM Transactions on Computer Systems}, publisher = {Association for Computing Machinery}, title = {{Kauri: BFT consensus with pipelined tree-based dissemination and aggregation}}, doi = {10.1145/3769423}, year = {2025}, } @inproceedings{21049, abstract = {Post-hoc importance attribution methods are a popular tool for “explaining” Deep Neural Networks (DNNs) and are inherently based on the assumption that the explanations can be applied independently of how the models were trained. Contrarily, in this work we bring forward empirical evidence that challenges this very notion. Surprisingly, we discover a strong dependency on and demonstrate that the training details of a pre-trained model’s classification layer (<10% of model parameters) play a crucial role, much more than the pre-training scheme itself. This is of high practical relevance: (1) as techniques for pre-training models are becoming increasingly diverse, understanding the interplay between these techniques and attribution methods is critical; (2) it sheds light on an important yet overlooked assumption of post-hoc attribution methods which can drastically impact model explanations and how they are interpreted eventually. With this finding we also present simple yet effective adjustments to the classification layers, that can significantly enhance the quality of model explanations. We validate our findings across several visual pre-training frameworks (fully-supervised, self-supervised, contrastive vision-language training) and analyse how they impact explanations for a wide range of attribution methods on a diverse set of evaluation metrics.}, author = {Gairola, Siddhartha and Böhle, Moritz and Locatello, Francesco and Schiele, Bernt}, booktitle = {13th International Conference on Learning Representations}, location = {Singapore}, publisher = {ICLR}, title = {{How to probe: Simple yet effective techniques for improving post-hoc explanations}}, year = {2025}, } @article{21052, abstract = {Program logics have proven a successful strategy for verification of complex programs. By providing local reasoning and means of abstraction and composition, they allow reasoning principles for individual components of a program to be combined to prove guarantees about a whole program. Crucially, these components and their proofs can be reused. However, this reuse is only available once the program logic has been defined. It is a frustrating fact of the status quo that whoever defines a new program logic must establish every part, both semantics and proof rules, from scratch. In spite of programming languages and program logics typically sharing many core features, reuse is generally not available across languages. Even inside one language, if the same underlying operation appears in multiple language primitives, reuse is typically not possible when establishing proof rules for the program logic. To enable reuse across and inside languages when defining complex program logics (and proving them sound), we serve program logics à la carte by combining program logic fragments for the various effects of the language. Among other language features, the menu includes shared state, concurrency, and non-determinism as reusable, composable blocks that can be combined to define a program logic modularly. Our theory builds on ITrees as a framework to express language semantics and Iris as the underlying separation logic; the work has been mechanized in the Coq proof assistant.}, author = {Vistrup, Max and Sammler, Michael Joachim and Jung, Ralf}, issn = {2475-1421}, journal = {Proceedings of the ACM on Programming Languages}, number = {POPL}, pages = {300--331}, publisher = {Association for Computing Machinery}, title = {{Program logics à la Carte}}, doi = {10.1145/3704847}, volume = {9}, year = {2025}, } @article{21053, abstract = {Program verification tools are often implemented as front-end translations of an input program into an intermediate verification language (IVL) such as Boogie, GIL, Viper, or Why3. The resulting IVL program is then verified using an existing back-end verifier. A soundness proof for such a translational verifier needs to relate the input program and verification logic to the semantics of the IVL, which in turn needs to be connected with the verification logic implemented in the back-end verifiers. Performing such proofs is challenging due to the large semantic gap between the input and output programs and logics, especially for complex verification logics such as separation logic. This paper presents a formal framework for reasoning about translational separation logic verifiers. At its center is a generic core IVL that captures the essence of different separation logics. We define its operational semantics and formally connect it to two different back-end verifiers, which use symbolic execution and verification condition generation, resp. Crucially, this semantics uses angelic non-determinism to enable the application of different proof search algorithms and heuristics in the back-end verifiers. An axiomatic semantics for the core IVL simplifies reasoning about the front-end translation by performing essential proof steps once and for all in the equivalence proof with the operational semantics rather than for each concrete front-end translation. We illustrate the usefulness of our formal framework by instantiating our core IVL with elements of Viper and connecting it to two Viper back-ends as well as a front-end for concurrent separation logic. All our technical results have been formalized in Isabelle/HOL, including the core IVL and its semantics, the semantics of two back-ends for a subset of Viper, and all proofs.}, author = {Dardinier, Thibault and Sammler, Michael Joachim and Parthasarathy, Gaurav and Summers, Alexander J. and Müller, Peter}, issn = {2475-1421}, journal = {Proceedings of the ACM on Programming Languages}, number = {POPL}, pages = {569--599}, publisher = {Association for Computing Machinery}, title = {{Formal foundations for translational separation logic verifiers}}, doi = {10.1145/3704856}, volume = {9}, year = {2025}, } @article{21057, abstract = {Among the most puzzling early discoveries of JWST are “little red dots” (LRDs), compact red sources that host broad Balmer emission lines, and in many cases exhibit a “V-shaped” change in slope in the rest-optical. The physical properties of LRDs currently have order-of-magnitude uncertainties, because models to explain the continuum of these sources differ immensely. Here, we leverage the complete selection of red sources in the RUBIES program, supplemented with public PRISM spectra, to study the origin of this V shape. By fitting a broken power law with a flexible inflection point, we find that a large fraction of red Hα emitters at 2 < z < 6 exhibit a strong change in slope, and that all strong inflections appear associated with the Balmer limit (0.3645 μm). Using a simple model of a reddened active galactic nucleus (AGN) with an unobscured scattered-light component, we demonstrate that the observed V shape in LRDs is unlikely to occur at any specific wavelength if the entire continuum is dominated by light from a power-law AGN continuum. In contrast, models with an intrinsic feature at the Balmer limit, such as those that are dominated by an evolved stellar population, can produce the observed spectral shapes, provided that a reddened component picks up sufficiently redward of the break. While no model can comfortably explain the full LRD spectral energy distribution, the common inflection location suggests that a single component consistently dominates the rest-frame UV optical in LRDs, and that this component is associated with T ∼ 10^4 K hydrogen.}, author = {Setton, David J. and Greene, Jenny E. and de Graaff, Anna and Ma, Yilun 逸伦 and Leja, Joel and Matthee, Jorryt J and Bezanson, Rachel and Boogaard, Leindert A. and Cleri, Nikko J. and Katz, Harley and Labbe, Ivo and Maseda, Michael V. and McConachie, Ian and Miller, Tim B. and Price, Sedona H. and Suess, Katherine A. and van Dokkum, Pieter and Wang 王, Bingjie 冰洁 and Weibel, Andrea and Whitaker, Katherine E. and Williams, Christina C.}, issn = {1538-4357}, journal = {The Astrophysical Journal}, number = {1}, publisher = {IOP Publishing}, title = {{Little Red Dots at an inflection point: Ubiquitous v-shaped turnover consistently occurs at the Balmer limit}}, doi = {10.3847/1538-4357/ae1500}, volume = {995}, year = {2025}, } @article{21058, abstract = {Luminous broad Hα emission and red rest-optical spectral energy distributions (SEDs) are the hallmark of compact little red dots (LRDs), implying highly attenuated dusty starbursts and/or obscured active galactic nuclei (AGN). However, the lack of observed far-infrared (FIR) emission has proved difficult to reconcile with the implied attenuated luminosity in these models. Here, we utilize deep new Atacama Large Millimeter/submillimeter Array imaging, new and existing JWST/MIRI imaging, and archival Spitzer/Herschel imaging of two of the rest-optically brightest LRDs (z = 3.1 and z = 4.47) to place the strongest constraints on the IR luminosity in LRDs to date. The detections at λrest = 1–4 μm imply flat slopes in the rest-IR, ruling out a contribution from hot (T ≳ 500 K) dust. Similarly, FIR nondetections rule out any appreciable cold (T ≲ 75 K) dust component. Assuming energy balance, these observations are inconsistent with the typical FIR dust emission of dusty starbursts and quasar tori, which usually show a mixture of cold and hot dust. Additionally, our [C ii] nondetections rule out typical dusty starbursts. We compute empirical maximum IR SEDs and find that both LRDs must have log(LIR/L ) 12.2 at the 3σ level. These limits are in tension with the predictions of rest-optical spectrophotometric fits, be they galaxy-only, AGN-only, or composite. It is unlikely that LRDs are highly dust-reddened intrinsically blue sources with a dust temperature distribution that conspires to avoid current observing facilities. Rather, we favor an intrinsically redder LRD SED model that alleviates the need for strong dust attenuation.}, author = {Setton, David J. and Greene, Jenny E. and Spilker, Justin S. and Williams, Christina C. and Labbé, Ivo and Ma, Yilun 逸伦 and Wang, Bingjie 冰洁 and Whitaker, Katherine E. and Leja, Joel and de Graaff, Anna and Alberts, Stacey and Bezanson, Rachel and Boogaard, Leindert A. and Brammer, Gabriel and Cutler, Sam E. and Cleri, Nikko J. and Cooper, Olivia R. and Dayal, Pratika and Fujimoto, Seiji and Furtak, Lukas J. and Goulding, Andy D. and Hirschmann, Michaela and Kokorev, Vasily and Maseda, Michael V. and McConachie, Ian and Matthee, Jorryt J and Miller, Tim B. and Naidu, Rohan P. and Oesch, Pascal A. and Pan, Richard and Price, Sedona H. and Suess, Katherine A. and Weaver, John R. and Xiao, Mengyuan and Zhang, Yunchong and Zitrin, Adi}, issn = {2041-8213}, journal = {The Astrophysical Journal Letters}, publisher = {IOP Publishing}, title = {{A confirmed deficit of hot and cold dust emission in the most luminous Little Red Dots}}, doi = {10.3847/2041-8213/ade78b}, volume = {991}, year = {2025}, } @article{21060, abstract = {Compact, star-forming galaxies with high star formation rate surface densities (ΣSFR) are often efficient Lyman continuum (LyC) emitters at z ≤ 4.5, likely because intense stellar feedback creates low-density channels that allow photons to escape. Irregular or disturbed morphologies, such as those resulting from mergers, can also facilitate LyC escape by creating anisotropic gas distributions. We investigated the influence of galaxy morphology on LyC production and escape at redshifts 5 ≤ z ≤ 7 using observations from various James Webb Space Telescope (JWST) surveys. Our sample consists of 436 sources, which are predominantly low-mass (∼10^8.15 M ), star-forming galaxies with ionizing photon efficiency (ξion) values consistent with canonical expectations. Since direct measurements of fesc are not possible during the Epoch of Reionization (EoR), we predicted fesc for high-redshift galaxies by applying survival analysis to a subsample of LyC emitters from the Low-Redshift Lyman Continuum Survey (LzLCS), selected to be direct analogs of reionization-era galaxies. We find that these galaxies exhibit, on average, modest predicted escape fractions (∼0.04). In addition, we evaluated the correlation between morphological features and LyC emission. Our findings indicate that neither ξion nor the predicted fesc values show a significant correlation with the presence of merger signatures. This suggests that in low-mass galaxies at z ≥ 5, strong morphological disturbances are not the primary mechanism driving LyC emission and leakage. Instead, compactness and star formation activity likely play a more pivotal role in regulating LyC escape. }, author = {Mascia, Sara and Pentericci, L. and Llerena, M. and Calabrò, A. and Matthee, Jorryt J and Flury, S. and Pacucci, F. and Jaskot, A. and Amorín, R. O. and Bhatawdekar, R. and Castellano, M. and Cleri, N. and Costantin, L. and Davis, K. and Di Cesare, Claudia and Dickinson, M. and Fontana, A. and Guo, Y. and Giavalisco, M. and Holwerda, B. W. and Hu, W. and Huertas-Company, M. and Jung, Intae and Kartaltepe, J. and Kashino, D. and Koekemoer, A. M. and Lucas, R. A. and Lotz, J. and Napolitano, L. and Jogee, S. and Wilkins, S.}, issn = {1432-0746}, journal = {Astronomy & Astrophysics}, publisher = {EDP Sciences}, title = {{Little impact of mergers and galaxy morphology on the production and escape of ionizing photons in the early Universe}}, doi = {10.1051/0004-6361/202553760}, volume = {701}, year = {2025}, } @article{21061, abstract = {Detecting the first generation of stars, Population III (Pop III), has been a long-standing goal in astrophysics, yet they remain elusive even in the JWST era. Here we present a novel NIRCam-based selection method for Pop III galaxies, and carefully validate it through completeness and contamination simulations. We systematically search ≃ 500 arcmin2 across JWST legacy fields for Pop III candidates, including GLIMPSE, which, assisted by gravitational lensing, has produced JWST’s deepest NIRCam imaging thus far. We discover one promising Pop III galaxy candidate (GLIMPSE-16043) at z=6.50 -0.24 +0.03, a moderately lensed galaxy (µ = + 2.9 -0.2 +0.1) with an intrinsic UV magnitude of MUV= -15.89 -0.14 +0.12. It exhibits key Pop III features: strong Hα emission (rest-frame EW 2810 ± 550 Å); a Balmer jump; no dust (UV slope β = −2.34 ± 0.36); and undetectable metal lines (e.g., [O III]; [O III]/Hβ < 0.44), implying a gas-phase metallicity of Zgas/Z⊙ < 0.5%. These properties indicate the presence of a nascent, metal-deficient young stellar population (<5 Myr) with a stellar mass of ≃105 M⊙. Intriguingly, this source deviates significantly from the extrapolated UV–metallicity relation derived from recent JWST observations at z = 4–10, consistent with UV enhancement by a top-heavy Pop III initial mass function or the presence of an extremely metal-poor active galactic nucleus. We also derive the first observational constraints on the Pop III UV luminosity function at z ≃ 6–7. The volume density of GLIMPSE-16043 (≈10^−4 cMpc−3) is in excellent agreement with theoretical predictions, independently reinforcing its plausibility. This study demonstrates the power of our novel NIRCam method to finally reveal distant galaxies even more pristine than the Milky Way’s most metal-poor satellites, thereby promising to bring us closer to the first generation of stars than we have ever been before.}, author = {Fujimoto, Seiji and Naidu, Rohan P. and Chisholm, John and Atek, Hakim and Endsley, Ryan and Kokorev, Vasily and Furtak, Lukas J. and Pan, Richard and Liu, Boyuan and Bromm, Volker and Venditti, Alessandra and Visbal, Eli and Sarmento, Richard and Weibel, Andrea and Oesch, Pascal A. and Brammer, Gabriel and Schaerer, Daniel and Adamo, Angela and Berg, Danielle A. and Bezanson, Rachel and Bouwens, Rychard and Chemerynska, Iryna and Claeyssens, Adélaïde and Dessauges-Zavadsky, Miroslava and Frebel, Anna and Korber, Damien and Labbe, Ivo and Marques-Chaves, Rui and Matthee, Jorryt J and McQuinn, Kristen B. W. and Muñoz, Julian B. and Natarajan, Priyamvada and Saldana-Lopez, Alberto and Suess, Katherine A. and Volonteri, Marta and Zitrin, Adi}, issn = {1538-4357}, journal = {The Astrophysical Journal}, publisher = {IOP Publishing}, title = {{GLIMPSE: An ultrafaint ≃10^5 M⊙ Pop III galaxy candidate and first constraints on the Pop III UV luminosity function at z ≃ 6–7}}, doi = {10.3847/1538-4357/ade9a1}, volume = {989}, year = {2025}, }