TY - JOUR
T1 - Optimized Photometric Redshifts for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS)
AU - Kodra, Dritan
AU - Andrews, Brett H.
AU - Newman, Jeffrey A.
AU - L. Finkelstein, Steven
AU - Fontana, Adriano
AU - Hathi, Nimish
AU - Salvato, Mara
AU - Wiklind, Tommy
AU - Wuyts, Stijn
AU - Broussard, Adam
AU - Chartab, Nima
AU - Conselice, Christopher
AU - Cooper, M. C.
AU - Dekel, Avishai
AU - Dickinson, Mark
AU - Ferguson, Henry C.
AU - Gawiser, Eric
AU - Grogin, Norman A.
AU - Iyer, Kartheik
AU - Kartaltepe, Jeyhan
AU - Kassin, Susan
AU - Koekemoer, Anton M.
AU - Koo, David C.
AU - Lucas, Ray A.
AU - Mantha, Kameswara Bharadwaj
AU - McIntosh, Daniel H.
AU - Mobasher, Bahram
AU - Pacifici, Camilla
AU - Pérez-González, Pablo G.
AU - Santini, Paola
N1 - Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/1/1
Y1 - 2023/1/1
N2 - We present the first comprehensive release of photometric redshifts (photo- z's) from the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) team. We use statistics based upon the Quantile-Quantile (Q-Q) plot to identify biases and signatures of underestimated or overestimated errors in photo- z probability density functions (PDFs) produced by six groups in the collaboration; correcting for these effects makes the resulting PDFs better match the statistical definition of a PDF. After correcting each group’s PDF, we explore three methods of combining the different groups’ PDFs for a given object into a consensus curve. Two of these methods are based on identifying the minimum f-divergence curve, i.e., the PDF that is closest in aggregate to the other PDFs in a set (analogous to the median of an array of numbers). We demonstrate that these techniques yield improved results using sets of spectroscopic redshifts independent of those used to optimize PDF modifications. The best photo- z PDFs and point estimates are achieved with the minimum f-divergence using the best four PDFs for each object (mFDa4) and the hierarchical Bayesian (HB4) methods, respectively. The HB4 photo- z point estimates produced σ NMAD = 0.0227/0.0189 and ∣Δz/(1 + z)∣ > 0.15 outlier fraction = 0.067/0.019 for spectroscopic and 3D Hubble Space Telescope redshifts, respectively. Finally, we describe the structure and provide guidance for the use of the CANDELS photo- z catalogs, which are available at https://archive.stsci.edu/prepds/candels/.
AB - We present the first comprehensive release of photometric redshifts (photo- z's) from the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) team. We use statistics based upon the Quantile-Quantile (Q-Q) plot to identify biases and signatures of underestimated or overestimated errors in photo- z probability density functions (PDFs) produced by six groups in the collaboration; correcting for these effects makes the resulting PDFs better match the statistical definition of a PDF. After correcting each group’s PDF, we explore three methods of combining the different groups’ PDFs for a given object into a consensus curve. Two of these methods are based on identifying the minimum f-divergence curve, i.e., the PDF that is closest in aggregate to the other PDFs in a set (analogous to the median of an array of numbers). We demonstrate that these techniques yield improved results using sets of spectroscopic redshifts independent of those used to optimize PDF modifications. The best photo- z PDFs and point estimates are achieved with the minimum f-divergence using the best four PDFs for each object (mFDa4) and the hierarchical Bayesian (HB4) methods, respectively. The HB4 photo- z point estimates produced σ NMAD = 0.0227/0.0189 and ∣Δz/(1 + z)∣ > 0.15 outlier fraction = 0.067/0.019 for spectroscopic and 3D Hubble Space Telescope redshifts, respectively. Finally, we describe the structure and provide guidance for the use of the CANDELS photo- z catalogs, which are available at https://archive.stsci.edu/prepds/candels/.
UR - http://www.scopus.com/inward/record.url?scp=85146077417&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ac9f12
DO - 10.3847/1538-4357/ac9f12
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AN - SCOPUS:85146077417
SN - 0004-637X
VL - 942
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 36
ER -