TY - JOUR
T1 - Two Massive, Compact, and Dust-obscured Candidate z ≃ 8 Galaxies Discovered by JWST
AU - Akins, Hollis B.
AU - Casey, Caitlin M.
AU - Allen, Natalie
AU - Bagley, Micaela B.
AU - Dickinson, Mark
AU - Finkelstein, Steven L.
AU - Franco, Maximilien
AU - Harish, Santosh
AU - Haro, Pablo Arrabal
AU - Ilbert, Olivier
AU - Kartaltepe, Jeyhan S.
AU - Koekemoer, Anton M.
AU - Liu, Daizhong
AU - Long, Arianna S.
AU - McCracken, Henry Joy
AU - Paquereau, Louise
AU - Papovich, Casey
AU - Pirzkal, Nor
AU - Rhodes, Jason
AU - Robertson, Brant E.
AU - Shuntov, Marko
AU - Toft, Sune
AU - Yang, Guang
AU - Barro, Guillermo
AU - Bisigello, Laura
AU - Buat, Véronique
AU - Champagne, Jaclyn B.
AU - Cooper, Olivia
AU - Costantin, Luca
AU - de la Vega, Alexander
AU - Drakos, Nicole E.
AU - Faisst, Andreas
AU - Fontana, Adriano
AU - Fujimoto, Seiji
AU - Gillman, Steven
AU - Gómez-Guijarro, Carlos
AU - Gozaliasl, Ghassem
AU - Hathi, Nimish P.
AU - Hayward, Christopher C.
AU - Hirschmann, Michaela
AU - Holwerda, Benne W.
AU - Jin, Shuowen
AU - Kocevski, Dale D.
AU - Kokorev, Vasily
AU - Lambrides, Erini
AU - Lucas, Ray A.
AU - Magdis, Georgios E.
AU - Magnelli, Benjamin
AU - McKinney, Jed
AU - Mobasher, Bahram
AU - Cosmos-Web Team
AU - CEERS team
N1 - Funding Information:
Support for this work was provided by NASA through grants JWST-GO-01727 and HST-AR-15802 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. H.B.A. acknowledges the support of the UT Austin Astronomy Department and thanks the UT Austin College of Natural Sciences for support through the Harrington Graduate Fellowship. C.M.C. thanks the National Science Foundation for support through grants AST-1814034 and AST-2009577, as well as the University of Texas at Austin College of Natural Sciences for support; C.M.C. also acknowledges support from the Research Corporation for Science Advancement from a 2019 Cottrell Scholar Award sponsored by IF/THEN, an initiative of Lyda Hill Philanthropies.
Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/10/1
Y1 - 2023/10/1
N2 - We present a search for extremely red, dust-obscured, z > 7 galaxies with JWST/NIRCam+MIRI imaging over the first 20 arcmin2 of publicly available Cycle 1 data from the COSMOS-Web, CEERS, and PRIMER surveys. Based on their red color in F277W−F444W (∼2.5 mag) and detection in MIRI/F770W (∼25 mag), we identify two galaxies, COS-z8M1 and CEERS-z7M1, that have best-fit photometric redshifts of z = 8.4 − 0.4 + 0.3 and 7.6 − 0.1 + 0.1 , respectively. We perform spectral energy distribution fitting with a variety of codes (including bagpipes, prospector, beagle, and cigale) and find a >95% probability that these indeed lie at z > 7. Both sources are compact (R eff ≲ 200 pc) and highly obscured (A V ∼ 1.5-2.5) and, at our best-fit redshift estimates, likely have strong [O iii]+Hβ emission contributing to their 4.4 μm photometry. We estimate stellar masses of ∼1010 M ⊙ for both sources; by virtue of detection in MIRI at 7.7 μm, these measurements are robust to the inclusion of bright emission lines, for example, from an active galactic nucleus. We identify a marginal (2.9σ) Atacama Large Millimeter/submillimeter Array detection at 2 mm within 0.″5 of COS-z8M1, which, if real, would suggest a remarkably high IR luminosity of ∼1012 L ⊙. These two galaxies, if confirmed at z ∼ 8, would be extreme in their stellar and dust masses and may be representative of a substantial population of highly dust-obscured galaxies at cosmic dawn.
AB - We present a search for extremely red, dust-obscured, z > 7 galaxies with JWST/NIRCam+MIRI imaging over the first 20 arcmin2 of publicly available Cycle 1 data from the COSMOS-Web, CEERS, and PRIMER surveys. Based on their red color in F277W−F444W (∼2.5 mag) and detection in MIRI/F770W (∼25 mag), we identify two galaxies, COS-z8M1 and CEERS-z7M1, that have best-fit photometric redshifts of z = 8.4 − 0.4 + 0.3 and 7.6 − 0.1 + 0.1 , respectively. We perform spectral energy distribution fitting with a variety of codes (including bagpipes, prospector, beagle, and cigale) and find a >95% probability that these indeed lie at z > 7. Both sources are compact (R eff ≲ 200 pc) and highly obscured (A V ∼ 1.5-2.5) and, at our best-fit redshift estimates, likely have strong [O iii]+Hβ emission contributing to their 4.4 μm photometry. We estimate stellar masses of ∼1010 M ⊙ for both sources; by virtue of detection in MIRI at 7.7 μm, these measurements are robust to the inclusion of bright emission lines, for example, from an active galactic nucleus. We identify a marginal (2.9σ) Atacama Large Millimeter/submillimeter Array detection at 2 mm within 0.″5 of COS-z8M1, which, if real, would suggest a remarkably high IR luminosity of ∼1012 L ⊙. These two galaxies, if confirmed at z ∼ 8, would be extreme in their stellar and dust masses and may be representative of a substantial population of highly dust-obscured galaxies at cosmic dawn.
UR - http://www.scopus.com/inward/record.url?scp=85175036310&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/acef21
DO - 10.3847/1538-4357/acef21
M3 - Article
AN - SCOPUS:85175036310
SN - 0004-637X
VL - 956
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 61
ER -