COSMOS-Web TeamCEERS TeamAkins, Hollis B.Casey, Caitlin M.Allen, NatalieBagley, Micaela B.Dickinson, MarkFinkelstein, Steven L.Franco, MaximilienHarish, SantoshHaro, Pablo ArrabalIlbert, OlivierKartaltepe, Jeyhan S.Koekemoer, Anton M.Liu, DaizhongLong, Arianna S.McCracken, Henry JoyPaquereau, LouisePapovich, CaseyPirzkal, NorRhodes, JasonRobertson, Brant E.Shuntov, MarkoToft, SuneYang, GuangBarro, GuillermoBisigello, LauraBuat, VeroniqueChampagne, Jaclyn B.Cooper, OliviaCostantin, Lucade la Vega, AlexanderDrakos, Nicole E.Faisst, AndreasFontana, AdrianoFujimoto, SeijiGillman, StevenGomez-Guijarro, CarlosGozaliasl, GhassemHathi, Nimish P.Hayward, Christopher C.Hirschmann, MichaelaHolwerda, Benne W.Jin, ShuowenKocevski, Dale D.Kokorev, VasilyLambrides, EriniLucas, Ray A.Magdis, Georgios E.Magnelli, BenjaminMcKinney, JedMobasher, BahramPerez-Gonzalez, Pablo G.Rich, R. MichaelSeille, Lise-MarieTalia, MargheritaUrry, C. MeganValentino, FrancescoWhitaker, Katherine E.Yung, L. Y. AaronZavala, Jorge2024-02-162024-02-162024-02-162023-10-0110.3847/1538-4357/acef21https://infoscience.epfl.ch/handle/20.500.14299/203865WOS:001083924000001We present a search for extremely red, dust-obscured, z > 7 galaxies with JWST/NIRCam+MIRI imaging over the first 20 arcmin(2) of publicly available Cycle 1 data from the COSMOS-Web, CEERS, and PRIMER surveys. Based on their red color in F277W-F444W (similar to 2.5 mag) and detection in MIRI/F770W (similar to 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 less than or similar to 200 pc) and highly obscured (A(V) similar to 1.5-2.5) and, at our best-fit redshift estimates, likely have strong [O III]+H beta emission contributing to their 4.4 mu m photometry. We estimate stellar masses of similar to 10(10) M-circle dot for both sources; by virtue of detection in MIRI at 7.7 mu m, these measurements are robust to the inclusion of bright emission lines, for example, from an active galactic nucleus. We identify a marginal (2.9 sigma) 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 similar to 10(12) L-circle dot. These two galaxies, if confirmed at z similar to 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.Physical SciencesSpectral Energy-DistributionsStellar Population SynthesisSpace-Telescope ObservationsStar-Formation HistoryHigh-Redshift GalaxiesBroad-Band PhotometryLyman-Break GalaxiesHigh-Z ExplorationLuminosity FunctionEmission-Linestext::journal::journal article::research article