J/A+A/710/A202 CAMIRA clusters in the eFEDS field (Nguyen-Dang+, 2026)
The eROSITA Final Equatorial-Depth Survey (eFEDS).
X-ray stacking analysis of Subaru's optically selected clusters spanning
low-richness regime.
Nguyen-Dang N.T., Ota N., Okabe N., Oguri M., Mitsuishi I., Reiprich T.H.,
Pacaud F., Bulbul E., Sanders J.S., Brueggen M., Liu A., Tsujita Y.,
Chiu I., Ghirardini V., Grandis S., Klein M., Migkas K., Miyatake H.,
Miyazaki S., Ramos-Ceja M.E.
<Astron. Astrophys. 710, A202 (2026)>
=2026A&A...710A.202N 2026A&A...710A.202N (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; X-ray sources ; Morphology
Keywords: galaxies: clusters: intracluster medium - intergalactic medium -
X-rays: galaxies: clusters
Abstract:
This is the second paper in a series exploring the X-ray properties of
galaxy clusters optically selected by the Subaru Hyper Suprime-Cam
(HSC) survey, using data from the SRG/eROSITA Final Equatorial-Depth
Survey (eFEDS).
We aim to investigate scaling relations between observable cluster
properties and mass, and to study the radial X-ray profiles of a large
sample of optically selected clusters.
We analyze a sample of 997 CAMIRA clusters with richness N>15 and
redshifts of 0.1<z<1.3. Using bolometric luminosities derived
from count rates and a weak-lensing mass calibration, we study the
L-M and N-M scaling relations through stacking analysis, while
accounting for selection effects and redshift evolution. We also
compare clusters with and without X-ray counterparts in the eFEDS
catalog in terms of their scaling relations and surface brightness
profiles.
The best-fit L-M slope (1.56+0.14-0.12) is slightly steeper
than the self-similar prediction, yet remains consistent with our
previous findings. The N-M slope (0.766+0.070-0.060) broadly
agrees with theoretical expectations and other optical samples. The
data do not require any additional redshift evolution beyond the
standard self-similar scaling, although current constraints on
evolution remain weak. X-ray detected clusters exhibit a marginally
steeper L-M slope, higher central surface brightness, and more
centrally concentrated X-ray profiles than undetected systems.
Our results highlight systematic differences in the X-ray properties
between optically and X-ray selected cluster samples. This study
extends scaling relation analyses into lower mass and luminosity
regimes, demonstrating the value of combining deep X-ray and optical
surveys like eROSITA and Subaru HSC.
Description:
This catalog contains 997 clusters from the CAMIRA optical cluster
sample version S20A v2 in the eFEDS footprint. Positions (z, RA, Dec)
and optical richness (N) of the clusters are taken from the CAMIRA
catalog, as well as the derived characteristic radius (R500) and
bolometric X-ray luminosity (L, L_err) are included.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 997 CAMIRA clusters in the eFEDS field
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See also:
J/MNRAS/444/147 : Richness of galaxy clusters (Oguri, 2014)
J/PASJ/70/S20 : HSC Wide S16A cluster catalog (Oguri+, 2018)
J/A+A/661/A1 : The eFEDS X-ray catalogs (V7.4) (Brunner+, 2022)
J/A+A/661/A3 : eFEDS counterparts to point-like sources (Salvato+, 2022)
J/A+A/661/A4 : eFEDS optical cluster and group catalog (Klein+, 2022)
J/A+A/661/A5 : The eFEDS AGN catalog (Liu+, 2022)
J/A+A/661/A7 : X-ray properties of eFEDS clusters and groups (Bahar+, 2022)
J/A+A/661/A10 : eFEDS galaxy clusters and groups in disguise (Bulbul+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Cluster Cluster name in the CAMIRA catalog
20- 24 F5.3 --- z Cluster redshift
26- 30 F5.1 --- Nmem Optical richness
32- 36 F5.3 Mpc R500 Radius enclosing density 500 times the
critical density
38- 42 F5.1 arcsec R500arcsec R500 in angular units
44- 51 F8.4 deg RAdeg Right ascension (J2000.0)
53- 59 F7.4 deg DEdeg Declination (J2000.0)
61- 66 F6.1 10+35W LX Cluster X-ray luminosity
(0.01-30.0 keV) (in 10+42erg/s)
68- 72 F5.1 10+35W e_LX 1-sigma uncertainty or upper limit of
luminosity
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Acknowledgements:
Naomi Ota, naomi(at)astro.uni-bonn.de
References:
Predehl et al., 2021A&A...647A...1P 2021A&A...647A...1P, The eROSITA X-ray telescope on SRG
License: CC-BY-4.0 [see https://spdx.org/licenses/]
(End) Nhan Nguyen [Univ. Tuebingen], Patricia Vannier [CDS] 17-Apr-2026