The PAU Survey: Photometric redshift estimation in deep wide fields
2023
Online
report
We present photometric redshifts (photo-$z$) for the deep wide fields of the Physics of the Accelerating Universe Survey (PAUS), covering an area of $\sim$50 deg$^{2}$, for $\sim$1.8 million objects up to $i_{\textrm{AB}}<23$. The PAUS deep wide fields overlap with the W1 and W3 fields from CFHTLenS and the G09 field from KiDS/GAMA. Photo-$z$ are estimated using the 40 narrow bands (NB) of PAUS and the broad bands (BB) of CFHTLenS and KiDS. We compute the redshifts with the SED template-fitting code BCNZ, with a modification in the calibration technique of the zero-point between the observed and the modelled fluxes, that removes any dependence on spectroscopic redshift samples. We enhance the redshift accuracy by introducing an additional photo-$z$ estimate ($z_{\textrm{b}}$), obtained through the combination of the BCNZ and the BB-only photo-$z$. Comparing with spectroscopic redshifts estimates ($z_{\textrm{s}}$), we obtain a $\sigma_{68} \simeq 0.019$ for all galaxies with $i_{\textrm{AB}}<23$ and a typical bias $|z_{\textrm{b}}-z_{\textrm{s}}|$ smaller than 0.01. For $z_{\textrm{b}} \sim (0.10-0.75)$ we find $\sigma_{68} \simeq (0.003-0.02)$, this is a factor of $10-2$ higher accuracy than the corresponding BB-only results. We obtain similar performance when we split the samples into red (passive) and blue (active) galaxies. We validate the redshift probability $p(z)$ obtained by BCNZ and compare its performance with that of $z_{\textrm{b}}$. These photo-$z$ catalogues will facilitate important science cases, such as the study of galaxy clustering and intrinsic alignment at high redshifts ($z \lesssim 1$) and faint magnitudes.
Comment: 24 pages, 26 figures, submitted to MNRAS
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The PAU Survey: Photometric redshift estimation in deep wide fields
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Autor/in / Beteiligte Person: | Navarro-Gironés, D. ; Gaztañaga, E. ; Crocce, M. ; Wittje, A. ; Hildebrandt, H. ; Wright, A. H. ; Siudek, M. ; Eriksen, M. ; Serrano, S. ; Renard, P. ; Gonzalez, E. J. ; Baugh, C. M. ; Cabayol, L. ; Carretero, J. ; Casas, R. ; Castander, F. J. ; De Vicente, J. ; Fernandez, E. ; García-Bellido, J. ; Hoekstra, H. ; Manzoni, G. ; Miquel, R. ; Padilla, C. ; Sánchez, E. ; Sevilla-Noarbe, I. ; Tallada-Crespí, P. |
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Veröffentlichung: | 2023 |
Medientyp: | report |
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