The Astrophysical Journal (Jan 2025)
GLIMPSE: An Ultrafaint ≃105 M⊙ Pop III Galaxy Candidate and First Constraints on the Pop III UV Luminosity Function at z ≃ 6–7
- Seiji Fujimoto,
- Rohan P. Naidu,
- John Chisholm,
- Hakim Atek,
- Ryan Endsley,
- Vasily Kokorev,
- Lukas J. Furtak,
- Richard Pan,
- Boyuan Liu,
- Volker Bromm,
- Alessandra Venditti,
- Eli Visbal,
- Richard Sarmento,
- Andrea Weibel,
- Pascal A. Oesch,
- Gabriel Brammer,
- Daniel Schaerer,
- Angela Adamo,
- Danielle A. Berg,
- Rachel Bezanson,
- Rychard Bouwens,
- Iryna Chemerynska,
- Adélaïde Claeyssens,
- Miroslava Dessauges-Zavadsky,
- Anna Frebel,
- Damien Korber,
- Ivo Labbe,
- Rui Marques-Chaves,
- Jorryt Matthee,
- Kristen B. W. McQuinn,
- Julian B. Muñoz,
- Priyamvada Natarajan,
- Alberto Saldana-Lopez,
- Katherine A. Suess,
- Marta Volonteri,
- Adi Zitrin
Affiliations
- Seiji Fujimoto
- ORCiD
- David A. Dunlap Department of Astronomy and Astrophysics, University of Toronto , 50 St. George Street, Toronto, Ontario, M5S 3H4, Canada ; [email protected]; Dunlap Institute for Astronomy and Astrophysics , 50 St. George Street, Toronto, Ontario, M5S 3H4, Canada; Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Rohan P. Naidu
- ORCiD
- MIT Kavli Institute for Astrophysics and Space Research , 70 Vassar Street, Cambridge, MA 02139, USA ; [email protected]
- John Chisholm
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Hakim Atek
- ORCiD
- Institut d’Astrophysique de Paris, CNRS, Sorbonne Université , 98bis Boulevard Arago, 75014, Paris, France
- Ryan Endsley
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Vasily Kokorev
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Lukas J. Furtak
- ORCiD
- Department of Physics, Ben-Gurion University of the Negev , P.O. Box 653, Be’er-Sheva 84105, Israel
- Richard Pan
- ORCiD
- Department of Physics & Astronomy, Tufts University , MA 02155, USA
- Boyuan Liu
- ORCiD
- Institut für Theoretische Astrophysik, Zentrum für Astronomie, Universität Heidelberg , D-69120 Heidelberg, Germany
- Volker Bromm
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Alessandra Venditti
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Eli Visbal
- ORCiD
- Department of Physics and Astronomy and Ritter Astrophysical Research Center, University of Toledo , 2801 W Bancroft Street, Toledo, OH 43606, USA
- Richard Sarmento
- ORCiD
- School of Earth and Space Exploration, Arizona State University , P.O. Box 871404, Tempe, AZ, 85287-1404, USA
- Andrea Weibel
- ORCiD
- Department of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, Switzerland
- Pascal A. Oesch
- ORCiD
- Department of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, Switzerland; Cosmic Dawn Center (DAWN) , Copenhagen, Denmark; Niels Bohr Institute, University of Copenhagen , Jagtvej 128, København N, DK-2200, Denmark
- Gabriel Brammer
- ORCiD
- Cosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen , Jagtvej 128, København N, DK-2200, Denmark
- Daniel Schaerer
- ORCiD
- Department of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, Switzerland
- Angela Adamo
- ORCiD
- Department of Astronomy, Oskar Klein center, Stockholm University , AlbaNova University center, SE-106 91 Stockholm, Sweden
- Danielle A. Berg
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Rachel Bezanson
- ORCiD
- Department of Physics and Astronomy and PITT PACC, University of Pittsburgh , Pittsburgh, PA 15260, USA
- Rychard Bouwens
- ORCiD
- Leiden Observatory, Leiden University , NL-2300 RA Leiden, The Netherlands
- Iryna Chemerynska
- ORCiD
- Institut d’Astrophysique de Paris, CNRS, Sorbonne Université , 98bis Boulevard Arago, 75014, Paris, France
- Adélaïde Claeyssens
- ORCiD
- Department of Astronomy, Oskar Klein center, Stockholm University , AlbaNova University center, SE-106 91 Stockholm, Sweden
- Miroslava Dessauges-Zavadsky
- ORCiD
- Department of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, Switzerland
- Anna Frebel
- ORCiD
- MIT Kavli Institute for Astrophysics and Space Research , 70 Vassar Street, Cambridge, MA 02139, USA ; [email protected]
- Damien Korber
- ORCiD
- Department of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, Switzerland
- Ivo Labbe
- ORCiD
- Centre for Astrophysics and Supercomputing, Swinburne University of Technology , Melbourne, VIC 3122, Australia
- Rui Marques-Chaves
- ORCiD
- Department of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, Switzerland
- Jorryt Matthee
- ORCiD
- Institute of Science and Technology Austria (ISTA) , Am Campus 1, 3400 Klosterneuburg, Austria
- Kristen B. W. McQuinn
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; Department of Physics & Astronomy, Rutgers, The State University of New Jersey , Piscataway, NJ 08854, USA
- Julian B. Muñoz
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Priyamvada Natarajan
- ORCiD
- Department of Astronomy, Yale University , 219 Prospect Street, New Haven, CT 06511, USA; Department of Physics, Yale University , 217 Prospect Street, New Haven, CT 06511, USA; Black Hole Initiative at Harvard University , 20 Garden Street, Cambridge, MA 02138, USA
- Alberto Saldana-Lopez
- ORCiD
- Department of Astronomy, Oskar Klein Centre, Stockholm University , 106 91 Stockholm, Sweden
- Katherine A. Suess
- ORCiD
- Department for Astrophysical & Planetary Science, University of Colorado , Boulder, CO 80309, USA
- Marta Volonteri
- ORCiD
- Institut d’Astrophysique de Paris, CNRS, Sorbonne Université , 98bis Boulevard Arago, 75014, Paris, France
- Adi Zitrin
- ORCiD
- Department of Physics, Ben-Gurion University of the Negev , P.O. Box 653, Be’er-Sheva 84105, Israel
- DOI
- https://doi.org/10.3847/1538-4357/ade9a1
- Journal volume & issue
-
Vol. 989,
no. 1
p. 46
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 arcmin ^2 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 $z=6.5{0}_{-0.24}^{+0.03}$ , a moderately lensed galaxy ( $\mu =2.{9}_{-0.2}^{+0.1}$ ) with an intrinsic UV magnitude of ${M}_{{\rm{UV}}}=-15.8{9}_{-0.14}^{+0.12}$ . It exhibits key Pop III features: strong H α 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 ]/H β < 0.44), implying a gas-phase metallicity of Z _gas / Z _⊙ < 0.5%. These properties indicate the presence of a nascent, metal-deficient young stellar population (<5 Myr) with a stellar mass of ≃10 ^5 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.
Keywords
- Population III stars
- Early universe
- High-redshift galaxies
- Young star clusters
- Interstellar medium
- Photoionization
