Paper: A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ∼ 12 Galaxy in Early JWST CEERS Imaging
Authors: 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, Anton M. Koekemoer, 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, Allison Kirkpatrick, Peter Kurczynski, Jennifer M. Lotz, Laura Pentericci, Nor Pirzkal, Swara Ravindranath, Russell E. Ryan, 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 Calabrò, 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, Kurt Hamblin, Timothy S. Hamilton, Nimish P. Hathi, Benne W. Holwerda, Michaela Hirschmann, Taylor A. Hutchison, Anne E. 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, David C. Nicholls, Viraj Pandya, Marc Rafelski, Kaila Ronayne, Paola Santini, Lise-Marie Seillé, Ekta A. Shah, Lu Shen, Raymond C. Simons, Gregory F. Snyder, Elizabeth R. Stanway, Amber N. Straughn, Harry I. Teplitz, Brittany N. Vanderhoof, Jesús Vega-Ferrero, Weichen Wang, Benjamin J. Weiner, Christopher N. A. Willmer, Stijn Wuyts, Jorge A. Zavala
Figure caption: (Left) The circles denote our fiducial photometry, with green and red denoting the HST/ACS+WFC3 and NIRCam instruments, respectively. This SED exhibits the hallmark shape of a high-redshift galaxy, with several nondetections in blue filters, followed by significant detections with a blue spectral slope. The arrows denote 1σ upper limits. The F115W − F200W break color is >1.9 mag (2σ), which is sufficient to rule out all low-redshift solutions. The blue curve shows the best-fitting EAZY model at z = 11.8. The orange curve shows the result if we force EAZY to find a solution at z < 7. This model is unable to match the amplitude of the break, as well as the slope redward of the break, and is correspondingly ruled out at high confidence (﹩{\chi }_{\mathrm{low}-z}^{2}﹩ =  54.5 compared to 15.8 for the z = 11.8 solution). (Right) Photometric redshift PDFs for Maisie’s Galaxy. The thick blue curve shows the fiducial PDF from EAZY, which exhibits no low-redshift solution and a peak at z = ﹩{11.8}_{-0.3}^{+0.2}﹩ (the purple curve shows the EAZY result without HST photometry, which prefers z = 12.0 and has a tail to z = 14). The remaining curves show the results from independent runs with PROSPECTOR, BAGPIPES, CIGALE, and DENSE BASIS (see Section 5). All results significantly prefer a z > 12 solution, with all four codes finding best-fit redshifts nearly identical to EAZY (z = ﹩{11.8}_{-0.3}^{+0.2}﹩, ﹩{11.6}_{-0.2}^{+0.2}﹩, 11.8﹩{}_{-0.4}^{+0.4}﹩, and ﹩{11.9}_{-0.4}^{+0.4}﹩, respectively).