A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging
Creators: name: Finkelstein, Steven L.
name: Bagley, Micaela B.
name: Haro, Pablo Arrabal
name: Dickinson, Mark
name: Ferguson, Henry C.
name: Kartaltepe, Jeyhan S.
name: Papovich, Casey
name: Burgarella, Denis
name: Kocevski, Dale D.
name: Huertas-Company, Marc
name: Iyer, Kartheik G.
name: Larson, Rebecca L.
name: Pérez-González, Pablo G.
name: Rose, Caitlin
name: Tacchella, Sandro
name: Wilkins, Stephen M.
name: Chworowsky, Katherine
name: Medrano, Aubrey
name: Morales, Alexa M.
name: Somerville, Rachel S.
name: Yung, L. Y. Aaron
name: Fontana, Adriano
name: Giavalisco, Mauro
name: Grazian, Andrea
name: Grogin, Norman A.
name: Kewley, Lisa J.
name: Koekemoer, Anton M.
name: Kirkpatrick, Allison
name: Kurczynski, Peter
name: Lotz, Jennifer M.
name: Pentericci, Laura
name: Pirzkal, Nor
name: Ravindranath, Swara
name: Ryan, Russell E.
name: Trump, Jonathan R.
name: Yang, Guang
name: Almaini, Omar
name: Amorín, Ricardo O.
name: Annunziatella, Marianna
name: Backhaus, Bren E.
name: Barro, Guillermo
name: Behroozi, Peter
name: Bell, Eric F.
name: Bhatawdekar, Rachana
name: Bisigello, Laura
name: Bromm, Volker
name: Buat, Véronique
name: Buitrago, Fernando
name: Calabró, Antonello
name: Casey, Caitlin M.
name: Castellano, Marco
name: Ortiz, Óscar A. Chávez
name: Ciesla, Laure
name: Cleri, Nikko J.
name: Cohen, Seth H.
name: Cole, Justin W.
name: Cooke, Kevin C.
name: Cooper, M. C.
name: Cooray, Asantha R.
name: Costantin, Luca
name: Cox, Isabella G.
name: Croton, Darren
name: Daddi, Emanuele
name: Davé, Romeel
name: de la Vega, Alexander
name: Dekel, Avishai
name: Elbaz, David
name: Estrada-Carpenter, Vicente
name: Faber, Sandra M.
name: Fernández, Vital
name: Finkelstein, Keely D.
name: Freundlich, Jonathan
name: Fujimoto, Seiji
name: García-Argumánez, Ángela
name: Gardner, Jonathan P.
name: Gawiser, Eric
name: Gómez-Guijarro, Carlos
name: Guo, Yuchen
name: Hamilton, Timothy S.
name: Hathi, Nimish P.
name: Holwerda, Benne W.
name: Hirschmann, Michaela
name: Hutchison, Taylor A.
name: Jaskot, Anne
name: Jha, Saurabh W.
name: Jogee, Shardha
name: Juneau, Stéphanie
name: Jung, Intae
name: Kassin, Susan A.
name: Bail, Aurélien Le
name: Leung, Gene C. K.
name: Lucas, Ray A.
name: Magnelli, Benjamin
name: Mantha, Kameswara Bharadwaj
name: Matharu, Jasleen
name: McGrath, Elizabeth J.
name: McIntosh, Daniel H.
name: Merlin, Emiliano
name: Mobasher, Bahram
name: Newman, Jeffrey A.
name: Nicholls, David C.
name: Pandya, Viraj
name: Rafelski, Marc
name: Ronayne, Kaila
name: Santini, Paola
name: Seillé, Lise-Marie
name: Shah, Ekta A.
name: Shen, Lu
name: Simons, Raymond C.
name: Snyder, Gregory F.
name: Stanway, Elizabeth R.
name: Straughn, Amber N.
name: Teplitz, Harry I.
name: Vanderhoof, Brittany N.
name: Vega-Ferrero, Jesús
name: Wang, Weichen
name: Weiner, Benjamin J.
name: Willmer, Christopher N. A.
name: Wuyts, Stijn
name: Zavala, Jorge A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the discovery of a candidate galaxy with a photo-z of z~12 in the first epoch of the JWST Cosmic Evolution Early Release Science (CEERS) Survey. Following conservative selection criteria we identify a source with a robust z_phot = 11.8^+0.3_-0.2 (1-sigma uncertainty) with m_F200W=27.3, and &gt;7-sigma detections in five filters. The source is not detected at lambda &lt; 1.4um in deep imaging from both HST and JWST, and has faint ~3-sigma detections in JWST F150W and HST F160W, which signal a Ly-alpha break near the red edge of both filters, implying z~12. This object (Maisie's Galaxy) exhibits F115W-F200W &gt; 1.9 mag (2-sigma lower limit) with a blue continuum slope, resulting in 99.6% of the photo-z PDF favoring z &gt; 11. All data quality images show no artifacts at the candidate's position, and independent analyses consistently find a strong preference for z &gt; 11. Its colors are inconsistent with Galactic stars, and it is resolved (r_h = 340 +/- 14 pc). Maisie's Galaxy has log M*/Msol ~ 8.5 and is highly star-forming (log sSFR ~ -8.2 yr^-1), with a blue rest-UV color (beta ~ -2.5) indicating little dust though not extremely low metallicity. While the presence of this source is in tension with most predictions, it agrees with empirical extrapolations assuming UV luminosity functions which smoothly decline with increasing redshift. Should followup spectroscopy validate this redshift, our Universe was already aglow with galaxies less than 400 Myr after the Big Bang.
description: 17 pages, 6 figures, 3 tables, ApJL in press. Summary of changes from original submission: Improvements in astrometry generated a weak detection in F150W that reduces the photo-z to 11.8 but does not increase the likelihood of lower-z solutions. A full discussion of changes from the original version is available at: https://web.corral.tacc.utexas.edu/ceersdata/papers/Maisie_update.pdf