Paper: COSMOS-Web: An Overview of the JWST Cosmic Origins Survey
Authors: Caitlin M. Casey, Jeyhan S. Kartaltepe, Nicole E. Drakos, Maximilien Franco, Santosh Harish, Louise Paquereau, Olivier Ilbert, Caitlin Rose, Isabella G. Cox, James W. Nightingale, Brant E. Robertson, John D. Silverman, Anton M. Koekemoer, Richard Massey, Henry Joy McCracken, Jason Rhodes, Hollis B. Akins, Natalie Allen, Aristeidis Amvrosiadis, Rafael C. Arango-Toro, Micaela B. Bagley, Angela Bongiorno, Peter L. Capak, Jaclyn B. Champagne, Nima Chartab, Óscar A. Chávez Ortiz, Katherine Chworowsky, Kevin C. Cooke, Olivia R. Cooper, Behnam Darvish, Xuheng Ding, Andreas L. Faisst, Steven L. Finkelstein, Seiji Fujimoto, Fabrizio Gentile, Steven Gillman, Katriona M. L. Gould, Ghassem Gozaliasl, Christopher C. Hayward, Qiuhan He, Shoubaneh Hemmati, Michaela Hirschmann, Knud Jahnke, Shuowen Jin, Ali Ahmad Khostovan, Vasily Kokorev, Erini Lambrides, Clotilde Laigle, Rebecca L. Larson, Gene C. K. Leung, Daizhong Liu, Tobias Liaudat, Arianna S. Long, Georgios Magdis, Guillaume Mahler, Vincenzo Mainieri, Sinclaire M. Manning, Claudia Maraston, Crystal L. Martin, Jacqueline E. McCleary, Jed McKinney, Conor J. R. McPartland, Bahram Mobasher, Rohan Pattnaik, Alvio Renzini, R. Michael Rich, David B. Sanders, Zahra Sattari, Diana Scognamiglio, Nick Scoville, Kartik Sheth, Marko Shuntov, Martin Sparre, Tomoko L. Suzuki, Margherita Talia, Sune Toft, Benny Trakhtenbrot, C. Megan Urry, Francesco Valentino, Brittany N. Vanderhoof, Eleni Vardoulaki, John R. Weaver, Katherine E. Whitaker, Stephen M. Wilkins, Lilan Yang, Jorge A. Zavala
Figure caption: Results of photometric redshift fitting to a set of mock galaxies; these mock galaxies have the full set of COSMOS photometry, spanning both existing ground- and space-based photometry (drawn from the limits described in Weaver et al. 2022b), as well as model photometry in the JWST bands corresponding to COSMOS-Web. On the left, we show the known redshifts of mock galaxies vs. the best-fit photometric redshifts, which are derived by performing spectral energy distribution (SED) fits with LEPHARE (Arnouts et al. 2002; Ilbert et al. 2006). Below z < 6, the purple heat map shows the density of sources down to F277W = 27.5 mag in 1% of our simulation for clarity; the orange heat map shows all simulated sources above z > 6. The thick black lines enclose the average dispersion about the 1-to-1 line as a function of redshift, as measured using the normalized median absolute deviation (σ NMAD). The average precision across all redshifts and magnitudes (down to 27.5) is 3.3%. At the top right, we show how the σ NMAD statistic varies as a function of F277W magnitude; sources down to 27th magnitude will have photometric redshifts precise to <5%, and sources closer to the detection threshold will have 10%–18% precision. At the bottom right, we show the anticipated outlier fraction (η) as a function of magnitude, defined as sources with photometric redshift precision worse than 15%. The outlier fraction is less than 5% down to ∼26.5, then increases toward 15% near the detection cutoff. Neither σ NMAD nor η show significant redshift dependence, other than slight spikes in the range 6 < z < 7 and 9 < z < 11. Gray bands show our 5σ point-source detection limits for two-integration and four-integration depths.