J/ApJ/862/12 Photometric Redshift Catalog (SCUSS, SDSS, WISE) (Gao+, 2018)
A photometric redshift catalog based on SCUSS, SDSS and WISE surveys.
Gao J., Zou H., Zhou X., Kong X.
<Astrophys. J. 862, 12 (2018)>
=2018ApJ...862...12G 2018ApJ...862...12G (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Redshifts ; Surveys
Keywords: galaxies: clusters: general - galaxies: distances and redshifts -
galaxies: photometry
Abstract:
We publish a photometric redshift catalog based on imaging data of the
South Galactic Cap u-band Sky Survey, Sloan Digital Sky Survey (SDSS),
and Wide-field Infrared Survey Explorer (WISE). A total of 7
photometric bands are used, ranging from near ultraviolet to near
infrared. A local linear regression method is adopted to estimate the
photometric redshift with a dedicated spectroscopic training set. The
photometric redshift catalog contains about 23.1 million galaxies
classified by SDSS. Using the training set with redshift up to 0.8 and
r-band magnitude down to 22mag, we achieve an average bias of
Δznorm=0.000228, standard deviation of
σ(Δznorm)=0.019, and 3σ outlier rate of about
4.2%. The bias is less than 0.01 at z<0.6 and goes up to about 0.05 at
z∼0.8. Compared with SDSS photometric redshifts, our redshift
estimations are more accurate and have less bias.
Description:
Our photometric redshift catalog is based on SDSS galaxies with r-band
positive model flux measurements. The source type is from the SDSS
star/galaxy separation. The photometric redshift accuracy is dependent
on the photometric error, number of used filters, and completeness of
the training set. In our catalog, we only provide the photometric
redshifts for galaxies with r<22mag and at least 5 filters with
colors within color cuts. Larger photometric errors and fewer colors
give much more catastrophic redshift estimations. There are total
23,067,608 galaxies with these constraints.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
scussphz.dat 237 23067608 Photometric redshifts of galaxies
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See also:
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
Byte-by-byte Description of file: scussphz.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- objID SDSS photometric object ID
21- 22 I2 --- Nn Number of the neighbors used for estimating
the photometric redshift
24 I1 --- Nf Number of filters having r<22mag and
colors within color cuts
26- 34 F9.5 deg RAdeg Right ascension (J2000)
36- 43 F8.5 deg DEdeg Declination (J2000)
45- 51 F7.3 --- zspec ?=-10 Spectroscopic redshift if exist
53- 58 F6.3 --- zphot Estimated photometric redshift by the local
linear regression model
60- 64 F5.3 --- e_zphot Estimated error for the photometric redshift
66- 71 F6.3 --- zbias Bias of the photometric redshift estimated
by the neighbors
73- 77 F5.3 --- zmean Average spectroscopic redshift of the
neighbors
79- 83 F5.3 --- zneareast Spectroscopic redshift of the nearest
neighbor in the multi-dimension color space
85- 89 F5.3 --- meanDist Average Euclidean distance of neighbors in
the multi-dimension color space
91- 97 F7.4 mag u*magmod ?=99 SCUSS u-band model magnitude
99-105 F7.4 mag umagmod ?=99 SDSS u-band model magnitude
107-113 F7.4 mag gmagmod ?=99 SDSS g-band model magnitude
115-121 F7.4 mag rmagmod ?=99 SDSS r-band model magnitude
123-129 F7.4 mag imagmod ?=99 SDSS i-band model magnitude
131-137 F7.4 mag zmagmod ?=99 SDSS z-band model magnitude
139-145 F7.4 mag W1magmod ?=99 WISE W 1 model magnitude
147-153 F7.4 mag W2magmod ?=99 WISE W 2 model magnitude
155-161 F7.4 mag e_u*magmod ?=99 SCUSS u-band model magnitude error
163-172 F10.4 mag e_umagmod ?=99 SDSS u-band model magnitude error
174-183 F10.4 mag e_gmagmod ?=99 SDSS g-band model magnitude error
185-191 F7.4 mag e_rmagmod ?=99 SDSS r-band model magnitude error
193-202 F10.4 mag e_imagmod ?=99 SDSS i-band model magnitude error
204-213 F10.4 mag e_zmagmod ?=99 SDSS z-band model magnitude error
215-225 F11.4 mag e_W1magmod ?=99 WISE W1 model magnitude error
227-237 F11.4 mag e_W2magmod ?=99 WISE W2 model magnitude error
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Acknowledgements:
Hu Zou, zouhu(at)nao.cas.cn
(End) Jinghua Gao [NAOC, China], Patricia Vannier [CDS] 09-Jul-2018