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arXiv · 2207.12474

A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging

Steven L. Finkelstein·Micaela B. Bagley·Pablo Arrabal Haro·Mark Dickinson·Henry C. Ferguson·Jeyhan S. Kartaltepe·Casey Papovich·Denis Burgarella·Dale D. Kocevski·Marc Huertas-Company·Kartheik G. Iyer·Rebecca L. Larson·Pablo G. Pérez-González·Caitlin Rose·Sandro Tacchella·Stephen M. Wilkins·Katherine Chworowsky·Aubrey Medrano·Alexa M. Morales·Rachel S. Somerville·L. Y. Aaron Yung·Adriano Fontana·Mauro Giavalisco·Andrea Grazian·Norman A. Grogin·Lisa J. Kewley·Anton M. Koekemoer·Allison Kirkpatrick·Peter Kurczynski·Jennifer M. Lotz·Laura Pentericci·Nor Pirzkal·Swara Ravindranath·Russell E. Ryan Jr.·Jonathan R. Trump·Guang Yang·Omar Almaini·Ricardo O. Amorín·Marianna Annunziatella·Bren E. Backhaus·Guillermo Barro·Peter Behroozi·Eric F. Bell·Rachana Bhatawdekar·Laura Bisigello·Volker Bromm·Véronique Buat·Fernando Buitrago·Antonello Calabró·Caitlin M. Casey·Marco Castellano·Óscar A. Chávez Ortiz·Laure Ciesla·Nikko J. Cleri·Seth H. Cohen·Justin W. Cole·Kevin C. Cooke·M. C. Cooper·Asantha R. Cooray·Luca Costantin·Isabella G. Cox·Darren Croton·Emanuele Daddi·Romeel Davé·Alexander de la Vega·Avishai Dekel·David Elbaz·Vicente Estrada-Carpenter·Sandra M. Faber·Vital Fernández·Keely D. Finkelstein·Jonathan Freundlich·Seiji Fujimoto·Ángela García-Argumánez·Jonathan P. Gardner·Eric Gawiser·Carlos Gómez-Guijarro·Yuchen Guo·Timothy S. Hamilton·Nimish P. Hathi·Benne W. Holwerda·Michaela Hirschmann·Taylor A. Hutchison·Anne Jaskot·Saurabh W. Jha·Shardha Jogee·Stéphanie Juneau·Intae Jung·Susan A. Kassin·Aurélien Le Bail·Gene C. K. Leung·Ray A. Lucas·Benjamin Magnelli·Kameswara Bharadwaj Mantha·Jasleen Matharu·Elizabeth J. McGrath·Daniel H. McIntosh·Emiliano Merlin·Bahram Mobasher·Jeffrey A. Newman
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Abstract

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 >7-sigma detections in five filters. The source is not detected at lambda < 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 > 1.9 mag (2-sigma lower limit) with a blue continuum slope, resulting in 99.6% of the photo-z PDF favoring z > 11. All data quality images show no artifacts at the candidate's position, and independent analyses consistently find a strong preference for z > 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.

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Steven L. Finkelstein, Micaela B. Bagley, Pablo Arrabal Haro, Mark Dickinson, Henry C. Ferguson, Jeyhan S. Kartaltepe, Casey Papovich, Denis Burgarella, Dale D. Kocevski, Marc Huertas-Company, Kartheik G. Iyer, Rebecca L. Larson, Pablo G. Pérez-González, Caitlin Rose, Sandro Tacchella, Stephen M. Wilkins, Katherine Chworowsky, Aubrey Medrano, Alexa M. Morales, Rachel S. Somerville, L. Y. Aaron Yung, Adriano Fontana, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Lisa J. Kewley, Anton M. Koekemoer, Allison Kirkpatrick, Peter Kurczynski, Jennifer M. Lotz, Laura Pentericci, Nor Pirzkal, Swara Ravindranath, Russell E. Ryan Jr., Jonathan R. Trump, Guang Yang, Omar Almaini, Ricardo O. Amorín, Marianna Annunziatella, Bren E. Backhaus, Guillermo Barro, Peter Behroozi, Eric F. Bell, Rachana Bhatawdekar, Laura Bisigello, Volker Bromm, Véronique Buat, Fernando Buitrago, Antonello Calabró, Caitlin M. Casey, Marco Castellano, Óscar A. Chávez Ortiz, Laure Ciesla, Nikko J. Cleri, Seth H. Cohen, Justin W. Cole, Kevin C. Cooke, M. C. Cooper, Asantha R. Cooray, Luca Costantin, Isabella G. Cox, Darren Croton, Emanuele Daddi, Romeel Davé, Alexander de la Vega, Avishai Dekel, David Elbaz, Vicente Estrada-Carpenter, Sandra M. Faber, Vital Fernández, Keely D. Finkelstein, Jonathan Freundlich, Seiji Fujimoto, Ángela García-Argumánez, Jonathan P. Gardner, Eric Gawiser, Carlos Gómez-Guijarro, Yuchen Guo, Timothy S. Hamilton, Nimish P. Hathi, Benne W. Holwerda, Michaela Hirschmann, Taylor A. Hutchison, Anne Jaskot, Saurabh W. Jha, Shardha Jogee, Stéphanie Juneau, Intae Jung, Susan A. Kassin, Aurélien Le Bail, Gene C. K. Leung, Ray A. Lucas, Benjamin Magnelli, Kameswara Bharadwaj Mantha, Jasleen Matharu, Elizabeth J. McGrath, Daniel H. McIntosh, Emiliano Merlin, Bahram Mobasher, Jeffrey A. Newman. 2022-09-07. A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging. https://doi.org/10.3847/2041-8213%2Fac966e

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