{"article_type":"original","publication_status":"published","publication_identifier":{"eissn":["1538-4357"],"issn":["0004-637X"]},"scopus_import":"1","date_created":"2026-01-28T15:25:17Z","date_updated":"2026-02-09T08:11:01Z","volume":989,"department":[{"_id":"JoMa"}],"doi":"10.3847/1538-4357/ade9a1","type":"journal_article","publication":"The Astrophysical Journal","article_processing_charge":"Yes","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","intvolume":"       989","day":"04","author":[{"first_name":"Seiji","last_name":"Fujimoto","full_name":"Fujimoto, Seiji"},{"full_name":"Naidu, Rohan P.","first_name":"Rohan P.","last_name":"Naidu"},{"first_name":"John","last_name":"Chisholm","full_name":"Chisholm, John"},{"last_name":"Atek","first_name":"Hakim","full_name":"Atek, Hakim"},{"full_name":"Endsley, Ryan","last_name":"Endsley","first_name":"Ryan"},{"first_name":"Vasily","last_name":"Kokorev","full_name":"Kokorev, Vasily"},{"full_name":"Furtak, Lukas J.","first_name":"Lukas J.","last_name":"Furtak"},{"full_name":"Pan, Richard","last_name":"Pan","first_name":"Richard"},{"last_name":"Liu","first_name":"Boyuan","full_name":"Liu, Boyuan"},{"first_name":"Volker","last_name":"Bromm","full_name":"Bromm, Volker"},{"last_name":"Venditti","first_name":"Alessandra","full_name":"Venditti, Alessandra"},{"full_name":"Visbal, Eli","first_name":"Eli","last_name":"Visbal"},{"full_name":"Sarmento, Richard","last_name":"Sarmento","first_name":"Richard"},{"full_name":"Weibel, Andrea","last_name":"Weibel","first_name":"Andrea"},{"full_name":"Oesch, Pascal A.","last_name":"Oesch","first_name":"Pascal A."},{"full_name":"Brammer, Gabriel","first_name":"Gabriel","last_name":"Brammer"},{"full_name":"Schaerer, Daniel","first_name":"Daniel","last_name":"Schaerer"},{"first_name":"Angela","last_name":"Adamo","full_name":"Adamo, Angela"},{"full_name":"Berg, Danielle A.","first_name":"Danielle A.","last_name":"Berg"},{"last_name":"Bezanson","first_name":"Rachel","full_name":"Bezanson, Rachel"},{"full_name":"Bouwens, Rychard","first_name":"Rychard","last_name":"Bouwens"},{"first_name":"Iryna","last_name":"Chemerynska","full_name":"Chemerynska, Iryna"},{"first_name":"Adélaïde","last_name":"Claeyssens","full_name":"Claeyssens, Adélaïde"},{"first_name":"Miroslava","last_name":"Dessauges-Zavadsky","full_name":"Dessauges-Zavadsky, Miroslava"},{"full_name":"Frebel, Anna","first_name":"Anna","last_name":"Frebel"},{"last_name":"Korber","first_name":"Damien","full_name":"Korber, Damien"},{"full_name":"Labbe, Ivo","last_name":"Labbe","first_name":"Ivo"},{"first_name":"Rui","last_name":"Marques-Chaves","full_name":"Marques-Chaves, Rui"},{"full_name":"Matthee, Jorryt J","first_name":"Jorryt J","last_name":"Matthee","id":"7439a258-f3c0-11ec-9501-9df22fe06720","orcid":"0000-0003-2871-127X"},{"full_name":"McQuinn, Kristen B. W.","last_name":"McQuinn","first_name":"Kristen B. W."},{"last_name":"Muñoz","first_name":"Julian B.","full_name":"Muñoz, Julian B."},{"full_name":"Natarajan, Priyamvada","first_name":"Priyamvada","last_name":"Natarajan"},{"full_name":"Saldana-Lopez, Alberto","first_name":"Alberto","last_name":"Saldana-Lopez"},{"last_name":"Suess","first_name":"Katherine A.","full_name":"Suess, Katherine A."},{"last_name":"Volonteri","first_name":"Marta","full_name":"Volonteri, Marta"},{"last_name":"Zitrin","first_name":"Adi","full_name":"Zitrin, Adi"}],"publisher":"IOP Publishing","oa_version":"Published Version","has_accepted_license":"1","year":"2025","DOAJ_listed":"1","PlanS_conform":"1","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"file":[{"checksum":"9e08e77ce6d818fafd074e2b6c30bc43","file_size":14405059,"relation":"main_file","date_created":"2026-02-09T07:57:01Z","content_type":"application/pdf","date_updated":"2026-02-09T07:57:01Z","file_id":"21167","file_name":"2025_AstrophysicalJournal_Fujimoto.pdf","access_level":"open_access","creator":"dernst","success":1}],"article_number":"46","citation":{"chicago":"Fujimoto, Seiji, Rohan P. Naidu, John Chisholm, Hakim Atek, Ryan Endsley, Vasily Kokorev, Lukas J. Furtak, et al. “GLIMPSE: An Ultrafaint ≃10^5 M⊙ Pop III Galaxy Candidate and First Constraints on the Pop III UV Luminosity Function at z ≃  6–7.” <i>The Astrophysical Journal</i>. IOP Publishing, 2025. <a href=\"https://doi.org/10.3847/1538-4357/ade9a1\">https://doi.org/10.3847/1538-4357/ade9a1</a>.","short":"S. Fujimoto, R.P. Naidu, J. Chisholm, H. Atek, R. Endsley, V. Kokorev, L.J. Furtak, R. Pan, B. Liu, V. Bromm, A. Venditti, E. Visbal, R. Sarmento, A. Weibel, P.A. Oesch, G. Brammer, D. Schaerer, A. Adamo, D.A. Berg, R. Bezanson, R. Bouwens, I. Chemerynska, A. Claeyssens, M. Dessauges-Zavadsky, A. Frebel, D. Korber, I. Labbe, R. Marques-Chaves, J.J. Matthee, K.B.W. McQuinn, J.B. Muñoz, P. Natarajan, A. Saldana-Lopez, K.A. Suess, M. Volonteri, A. Zitrin, The Astrophysical Journal 989 (2025).","ama":"Fujimoto S, Naidu RP, Chisholm J, et al. GLIMPSE: An ultrafaint ≃10^5 M⊙ Pop III galaxy candidate and first constraints on the Pop III UV luminosity function at z ≃  6–7. <i>The Astrophysical Journal</i>. 2025;989. doi:<a href=\"https://doi.org/10.3847/1538-4357/ade9a1\">10.3847/1538-4357/ade9a1</a>","mla":"Fujimoto, Seiji, et al. “GLIMPSE: An Ultrafaint ≃10^5 M⊙ Pop III Galaxy Candidate and First Constraints on the Pop III UV Luminosity Function at z ≃  6–7.” <i>The Astrophysical Journal</i>, vol. 989, 46, IOP Publishing, 2025, doi:<a href=\"https://doi.org/10.3847/1538-4357/ade9a1\">10.3847/1538-4357/ade9a1</a>.","ieee":"S. Fujimoto <i>et al.</i>, “GLIMPSE: An ultrafaint ≃10^5 M⊙ Pop III galaxy candidate and first constraints on the Pop III UV luminosity function at z ≃  6–7,” <i>The Astrophysical Journal</i>, vol. 989. IOP Publishing, 2025.","ista":"Fujimoto S, Naidu RP, Chisholm J, Atek H, Endsley R, Kokorev V, Furtak LJ, Pan R, Liu B, Bromm V, Venditti A, Visbal E, Sarmento R, Weibel A, Oesch PA, Brammer G, Schaerer D, Adamo A, Berg DA, Bezanson R, Bouwens R, Chemerynska I, Claeyssens A, Dessauges-Zavadsky M, Frebel A, Korber D, Labbe I, Marques-Chaves R, Matthee JJ, McQuinn KBW, Muñoz JB, Natarajan P, Saldana-Lopez A, Suess KA, Volonteri M, Zitrin A. 2025. GLIMPSE: An ultrafaint ≃10^5 M⊙ Pop III galaxy candidate and first constraints on the Pop III UV luminosity function at z ≃  6–7. The Astrophysical Journal. 989, 46.","apa":"Fujimoto, S., Naidu, R. P., Chisholm, J., Atek, H., Endsley, R., Kokorev, V., … Zitrin, A. (2025). GLIMPSE: An ultrafaint ≃10^5 M⊙ Pop III galaxy candidate and first constraints on the Pop III UV luminosity function at z ≃  6–7. <i>The Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/ade9a1\">https://doi.org/10.3847/1538-4357/ade9a1</a>"},"_id":"21061","ddc":["520"],"oa":1,"language":[{"iso":"eng"}],"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","month":"08","OA_place":"publisher","OA_type":"gold","abstract":[{"lang":"eng","text":"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."}],"quality_controlled":"1","date_published":"2025-08-04T00:00:00Z","status":"public","file_date_updated":"2026-02-09T07:57:01Z","acknowledgement":"We are grateful to the CEERS, PRIMER, JOF, UNCOVER, and GLIMPSE teams for developing their NIRCam surveys, and to the various JWST and HST surveys acknowledged in Section 3 that enabled our search. We thank Kimihiko Nakajima and Kohei Inayoshi for sharing Pop III and/or AGN templates, Steven Finkelstein for comments on the completeness and contamination rate simulation, Aaron Yung for SEDs of simulated galaxies, Joel Leja, Ben Johnson, and Sandro Tacchella for advise on SED fitting, and Takashi Kojima and Hiroto Yanagisawa for discussions.\r\n\r\nWe made extensive use of the DAWN JWST Archive for various comparisons presented in this paper. Some of the data products presented herein were retrieved from the Dawn JWST Archive (DJA). DJA is an initiative of the Cosmic Dawn Center (DAWN), which is funded by the Danish National Research Foundation under grant DNRF140. The prism spectra used in this paper were observed as part of the following programs, and we are grateful to these teams for helping build the rich spectroscopic legacy of JWST: 1180, 1181, 1210, 1286, 3215 (A. J. Bunker et al. 2024; F. D’Eugenio et al. 2024); 1211–1215 (M. V. Maseda et al. 2024); 1345 (S. L. Finkelstein et al. 2024); 1433 (T. Y.-Y. Hsiao et al. 2024); 1747 (G. Roberts-Borsani et al. 2025); 2028 (X. Wang et al. 2024); 2073 (PI: J. Hennawi); 2198 (L. Barrufet et al. 2025); 2282 (L. D. Bradley et al. 2023); 2561 (R. Bezanson et al. 2024; S. H. Price et al. 2024); 2565 (T. Nanayakkara et al. 2023); 2750 (P. Arrabal Haro et al. 2023b); 2756 (PI: W. Chen); 2767 (C. C. Williams et al. 2023); 3073 (M. Castellano et al. 2024); 4106 (PI: E. Nelson); 4233 (A. de Graaff et al. 2025); 4446 (B. L. Frye et al. 2024); 4557 (PI: H. Yan); 6541 (PI: E. Egami); 6585 (PI: D. Coulter).\r\n\r\nThis 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. The specific observations can be accessed via doi: 10.17909/xpxt-a441. These observations include data associated with program No. 03293. Support for program No. 03293 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.\r\n\r\nThis project has received funding from NASA through the NASA Hubble Fellowship grant HST-HF2-51505.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. This work has received funding from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract No. MB22.00072, as well as from the Swiss National Science Foundation (SNSF) through project grant 200020_207349. The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation under grant DNRF140. H.A. and I.C. acknowledge support from CNES, focused on the JWST mission, and the Programme National Cosmology and Galaxies (PNCG) of CNRS/INSU with INP and IN2P3, co-funded by CEA and CNES. I.C. acknowledges funding support from the Initiative Physique des Infinis (IPI), a research training program of the Idex SUPER at Sorbonne Université. A.Z. acknowledges support by grant No. 2020750 from the United States–Israel Binational Science Foundation (BSF) and grant No. 2109066 from the United States National Science Foundation (NSF); and by the Israel Science Foundation grant No. 864/23. P.N. acknowledges support from the Gordon and Betty Moore Foundation and the John Templeton Foundation that fund the black hole Initiative (BHI) at Harvard University, where she serves as one of the PIs. B.L. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy EXC 2181/1—390900948 (the Heidelberg STRUCTURES Excellence Cluster). Y.S. and G.M. have received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 833925, project STAREX)."}