J/A+A/688/A210 eRASS. Optical properties of clusters and groups (Kluge+, 2024)
The SRG/eROSITA All-Sky Survey. Optical identification and properties of galaxy
clusters and groups in the Western Galactic Hemisphere.
Kluge M., Comparat J., Liu A., Balzer F., Bulbul E., Ider Chitham J.,
Ghirardini V., Garrel C., Bahar Y.E., Artis E., Bender R., Clerc N.,
Dwelly T., Fabricius M. H., Grandis S., Hernandez-Lang D., Hill G.J.,
Joshi J., Lamer G., Merloni A., Nandra K., Pacaud F., Predehl P.,
Ramos-Ceja M.E., Reiprich T.H., Salvato M., Sanders J.S., Schrabback T.,
Seppi R., Zelmer S., Zenteno A., Zhang X.
<Astron. Astrophys. 688, A210 (2024)>
=2024A&A...688A.210K 2024A&A...688A.210K (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, optical ; Redshifts ; X-ray sources
Keywords: catalogs - surveys - galaxies: clusters: general -
galaxies: distances and redshifts - galaxies: groups: general -
X-rays: galaxies: clusters
Abstract:
The first SRG/All-Sky Survey (eRASS1) provides the largest
intracluster medium-selected galaxy cluster and group catalog covering
the western galactic hemisphere. Compared to samples selected purely
on X-ray extent, the sample purity can be enhanced by identifying
cluster candidates using optical and near-infrared data from the DESI
Legacy Imaging Surveys. Using the red-sequence-based cluster finder
eROMaPPer, we measure individual photometric properties (redshift
z_lambda richness lambda, optical center, and BCG position) for 12000
eRASS1 clusters over a sky area of 13116deg2, augmented by 247 cases
identified by matching the candidates with known clusters from the
literature. The median redshift of the identified eRASS1 sample is
z=0.31, with 10% of the clusters at z>0.72. The photometric redshifts
have an accuracy of deltaz/(1+z)<0.005 for 0.05<z<0.9. Spectroscopic
cluster properties (redshift z_spec and velocity dispersion sigma) are
measured a posteriori for a subsample of 3210 and 1499 eRASS1
clusters, respectively, using an extensive compilation of
spectroscopic redshifts of galaxies from the literature. We infer that
the primary eRASS1 sample has a purity of 86% and optical completeness
>95% for z>0.05. For these and further quality assessments of the
eRASS1 identified catalog, we apply our identification method to a
collection of galaxy cluster catalogs in the literature, as well as
blindly on the full Legacy Surveys covering 24069deg2. Using a
combination of these cluster samples, we investigate the velocity
dispersion-richness relation, finding that it scales with richness as
log(lambdanorm)=2.401*log(sigma)-5.074 with an intrinsic scatter of
deltain=0.10±0.01dex. The primary product of our work is the
identified eRASS1 cluster catalog with high purity and a well-defined
X-ray selection process, opening the path for precise cosmological
analyses presented in companion papers.
Description:
This catalog presents the optical properties of the eRASS1 identified
galaxy clusters and groups. It augments the X-ray information
published in Bulbul et al. (2024A&A...685A.106B 2024A&A...685A.106B, J/A+A/685/A106). It
was obtained by running the red-sequence-based cluster finder
eROMaPPer at the locations of the eRASS1 extended X-ray detections
using the optical and near-infrared source catalogs provided by the
Legacy Surveys DR9 and DR10.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablee1.dat 481 12247 Optical properties of clusters and groups
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See also:
J/A+A/682/A34 : SRG/eROSITA all-sky survey catalogs (eRASS1) (Merloni+, 2024)
J/A+A/683/A130 : eRASS Western Galactic Hemisphere Superclusters (Liu+, 2024)
J/A+A/685/A106 : eRASS. Galaxy clusters and groups in WGH (Bulbul+, 2024)
Byte-by-byte Description of file: tablee1.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Cluster name (NAME)
25- 56 A32 --- DetUId Unique eSASS detection ID (DETUID)
58- 65 F8.4 deg RAdeg Right ascension (J2000) of X-ray prior (RA)
67- 75 F9.5 deg DEdeg Declination (J2000) of X-ray prior (DEC)
77- 82 F6.2 arcsec ePos ? Uncertainty of RA, DEC (RADEErr)
84- 91 F8.4 deg RAOdeg ? Right ascension J2000 of optical center
(RAOPT)
93-101 F9.5 deg DEOdeg ? Declination J2000 of optical center
(DECOPT)
103-110 F8.4 deg RABdeg ? Right ascension (J2000) of the brightest
member BCG (RABCG)
112-120 F9.5 deg DEBdeg ? Declination J2000 of the brightest member
BCG (DECBCG)
122-127 F6.3 mag zmagBCG ? Galactic extinction-corrected z-band AB
magnitude of the brightest member BCG
(REFMAGBCG)
129-135 F7.5 --- Bestz Best available cluster redshift (BESTZ)
137-143 F7.5 --- e_Bestz ? Error of best available cluster redshift
(BESTZ)
145-155 A11 --- Bestztype Type of best available cluster redshift
(BESTZTYPE)
157-163 F7.5 --- zlambda ? Uncorrected cluster photometric redshift
(ZLAMBDA)
165-171 F7.5 --- e_zlambda ? Error of uncorrected cluster photometric
redshift (ZLAMBDA)
173-179 F7.5 --- zlambdacorr ? Bias-corrected cluster photometric
redshift (ZLAMBDACORR)
181-187 F7.5 --- E_zlambdacorr ? Upper error of bias-corrected cluster
photometric redshift (ZLAMBDACORR)
189-195 F7.5 --- e_zlambdacorr ? Lower error of bias-corrected cluster
photometric redshift (ZLAMBDACORR)
197-203 F7.5 --- zlambda2 ? Uncorrected foreground/background
cluster photometric redshift
(ZLAMBDASECOND)
205-211 F7.5 --- Litz ? Literature cluster redshift (LITZ)
213-219 F7.5 --- e_Litz ? Error of Literature cluster redshift
(LITZ)
221-238 A18 --- r_Litz ? Reference for LIT_Z (LITZSRC)
240-246 F7.5 --- SpeczBoot ? Bootstrap estimate of biweight
spectroscopic redshift (SPECZBOOT)
248-254 F7.5 --- e_SpeczBoot ? Bootstrap error of biweight
spectroscopic redshift (SPECZBOOT)
256-258 I3 --- Nmemb Number of members used in biweight redshift
and velocity dispersion estimate
(NMEMBERS)
260-266 F7.5 --- CGSpecz ? Spectroscopic redshift of the central
galaxy (CGSPECZ)
268-274 F7.5 --- e_CGSpecz ? Error of spectroscopic redshift of the
central galaxy (CGSPECZ)
276-282 F7.5 --- BCGSpecz ? Spectroscopic redshift of the brightest
member (BCGSPECZ)
284-291 F8.2 km/s vdispBoot ? Bootstrap estimate of velocity dispersion
(VDISPBOOT)
293-300 F8.2 km/s e_vdispBoot ? Error of bootstrap estimate of velocity
dispersion (VDISPBOOT)
302-305 F4.2 --- f_vdispBoot ? Fraction of diverged velocity clippings
(VDISPBOOTFLAG)
307-314 A8 --- vdispType ? Estimate used to determine vdisp. Gapper
or Biweight depending on number of members
(VDISPTYPE)
316-322 F7.2 --- LambdaN ? Richness normalized to the definition of
the grz run (LAMBDANORM)
324-330 F7.2 --- e_LambdaN ? Error of richness normalized to the
definition of the grz run (LAMBDANORM)
332-338 F7.2 --- LambdaOptN ? Richness (optical center) normalized to
the definition of the grz run
(LAMBDAOPTNORM)
340-346 F7.2 --- e_LambdaOptN ? Error of richness (optical center)
normalized to the definition of the
grz run (LAMBDAOPTNORM)
348-356 F9.5 --- ScaleVal ? Richness scale factor (SCALEVAL) (1)
358-362 F5.3 --- MaskFrac ? Fraction of cluster area which is masked
(MASKFRAC)
364-392 A29 --- Run ? RedMaPPer calibration:
surveybandsrefband_iteration (RUN)
394-401 F8.4 --- Lmax ? Optical maximum likelihood (LMAX)
403-409 F7.5 10+21cm-2 NHI HI column density from HI4PI, Nside=1024
(NHI)
411-420 F10.5 --- ExtLike Extent likelihood of the X-ray source
(EXTLIKE)
422-427 F6.4 --- Pcont Probability that the cluster is a
contaminant (PCONT)
429 I1 --- SharedMemb There is another cluster with ≥70% of the
same members and higher LMAX
(SHAREDMEMBERS)
431 I1 --- InfootPrint Cluster is within the optical survey
footprint (INFOOTPRINT)
433-437 F5.2 mag limgmag ? Limiting g-band galaxy magnitude
(LIMMAGG) (2)
439-443 F5.2 mag limrmag ? Limiting r-band galaxy magnitude
(LIMMAGR) (2)
445-449 F5.2 mag limimag ? Limiting i-band galaxy magnitude
(LIMMAGI) (2)
451-455 F5.2 mag limzmag ? Limiting z-band galaxy magnitude
(LIMMAGZ) (2)
457-461 F5.2 mag limW1mag ? Limiting w1-band galaxy magnitude
(LIMMAGW1) (2)
463 I1 --- inzvlim Photometric redshift is smaller than the
limiting optical survey redshift
ZVLIM_02 or ZVLIM_04 (INZVLIM)
465-469 F5.3 --- zvlim02 ? Maximum observable galaxy redshift
at 0.2L* volume limit (ZVLIM02)
471-475 F5.3 --- zvlim04 ? Maximum observable galaxy redshift at
0.4L* volume limit (ZVLIM04)
477 I1 --- Gaia [0/1] A star in the GAIA eDR3 catalog
brighter than 10 G mag is closer than 30
arcsec to the X-ray source
(GAIA10MAG30ARCSEC)
479 I1 --- NGC30 [0/1] A galaxy in the NGC catalog is closer
than 30 arcsec to the X-ray source
(NGC30ARCSEC)
481 I1 --- HECATE [0/1] A galaxy in the HECATE survey is
closer than 30 arcsec to the X-ray source
(HECATE30ARCSEC)
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Note (1): Corresponds to Eq. 2 in Rykoff et al. (2016ApJS..224....1R 2016ApJS..224....1R).
Note (2): From Rykoff et al. (2015arXiv.1509.00870) depth map model.
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Acknowledgements:
Matthias Kluge, mkluge(at)mpe.mpg.de
(End) Patricia Vannier [CDS] 07-Jun-2024