TY - JOUR
T1 - A Long Time Ago in a Galaxy Far, Far Away
T2 - A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging
AU - Finkelstein, Steven L.
AU - Bagley, Micaela B.
AU - Haro, Pablo Arrabal
AU - Dickinson, Mark
AU - Ferguson, Henry C.
AU - Kartaltepe, Jeyhan S.
AU - Papovich, Casey
AU - Burgarella, Denis
AU - Kocevski, Dale D.
AU - Huertas-Company, Marc
AU - Iyer, Kartheik G.
AU - Koekemoer, Anton M.
AU - Larson, Rebecca L.
AU - Pérez-González, Pablo G.
AU - Rose, Caitlin
AU - Tacchella, Sandro
AU - Wilkins, Stephen M.
AU - Chworowsky, Katherine
AU - Medrano, Aubrey
AU - Morales, Alexa M.
AU - Somerville, Rachel S.
AU - Aaron Yung, L. Y.
AU - Fontana, Adriano
AU - Giavalisco, Mauro
AU - Grazian, Andrea
AU - Grogin, Norman A.
AU - Kewley, Lisa J.
AU - Kirkpatrick, Allison
AU - Kurczynski, Peter
AU - Lotz, Jennifer M.
AU - Pentericci, Laura
AU - Pirzkal, Nor
AU - Ravindranath, Swara
AU - Ryan, Russell E.
AU - Trump, Jonathan R.
AU - Yang, Guang
AU - Almaini, Omar
AU - Amorín, Ricardo O.
AU - Annunziatella, Marianna
AU - Backhaus, Bren E.
AU - Barro, Guillermo
AU - Behroozi, Peter
AU - Bell, Eric F.
AU - Bhatawdekar, Rachana
AU - Bisigello, Laura
AU - Bromm, Volker
AU - Buat, Véronique
AU - Buitrago, Fernando
AU - Croton, Darren
AU - Nicholls, David C.
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/12/1
Y1 - 2022/12/1
N2 - We report the discovery of a candidate galaxy with a photo-z of z ~ 12 in the first epoch of the James Webb Space Telescope (JWST) Cosmic Evolution Early Release Science Survey. Following conservative selection criteria, we identify a source with a robust zphot = 11.8-0.2+0.3 (1σ uncertainty) with mF200W = 27.3 and ≥7σ detections in five filters. The source is not detected at λ < 1.4 μm in deep imaging from both Hubble Space Telescope (HST) and JWST and has faint ~3σ detections in JWST F150W and HST F160W, which signal a Lyα break near the red edge of both filters, implying z ~ 12. This object (Maisie's Galaxy) exhibits F115W-F200W > 1.9 mag (2σ lower limit) with a blue continuum slope, resulting in 99.6% of the photo-z probability distribution function 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 (rh = 340 ± 14 pc). Maisie's Galaxy has log M∗/M⊙ ~ 8.5 and is highly star-forming (log sSFR~-8.2 yr-1), with a blue rest- UV color (β~-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 that smoothly decline with increasing redshift. Should follow-up spectroscopy validate this redshift, our universe was already aglow with galaxies less than 400 Myr after the Big Bang.
AB - We report the discovery of a candidate galaxy with a photo-z of z ~ 12 in the first epoch of the James Webb Space Telescope (JWST) Cosmic Evolution Early Release Science Survey. Following conservative selection criteria, we identify a source with a robust zphot = 11.8-0.2+0.3 (1σ uncertainty) with mF200W = 27.3 and ≥7σ detections in five filters. The source is not detected at λ < 1.4 μm in deep imaging from both Hubble Space Telescope (HST) and JWST and has faint ~3σ detections in JWST F150W and HST F160W, which signal a Lyα break near the red edge of both filters, implying z ~ 12. This object (Maisie's Galaxy) exhibits F115W-F200W > 1.9 mag (2σ lower limit) with a blue continuum slope, resulting in 99.6% of the photo-z probability distribution function 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 (rh = 340 ± 14 pc). Maisie's Galaxy has log M∗/M⊙ ~ 8.5 and is highly star-forming (log sSFR~-8.2 yr-1), with a blue rest- UV color (β~-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 that smoothly decline with increasing redshift. Should follow-up spectroscopy validate this redshift, our universe was already aglow with galaxies less than 400 Myr after the Big Bang.
UR - http://www.scopus.com/inward/record.url?scp=85144295804&partnerID=8YFLogxK
U2 - 10.3847/2041-8213/ac966e
DO - 10.3847/2041-8213/ac966e
M3 - Article
SN - 2041-8205
VL - 940
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L55
ER -