J/A+A/683/A130 eRASS Western Galactic Hemisphere Superclusters (Liu+, 2024)
The SRG/eROSITA All-Sky Survey.
First Catalog of superclusters in the western Galactic hemisphere.
Liu A., Bulbul E., Kluge M., Ghirardini V., Zhang X., Sanders J.S.,
Artis E., Bahar Y.E., Balzer F., Bruggen M., Clerc N., Comparat J.,
Garrel C., Gatuzz E., Grandis S., Lamer G., Merloni A., Migkas K.,
Nandra K., Predehl P., Ramos-Ceja M.E., Reiprich T.H., Seppi R., Zelmer S.
<Astron. Astrophys. 683, A130 (2024)>
=2024A&A...683A.130L 2024A&A...683A.130L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies ; X-ray sources ; Redshifts
Keywords: galaxies: clusters: general - large-scale structure of Universe -
X-rays: galaxies: clusters
Abstract:
Superclusters of galaxies mark the large-scale overdense regions in
the Universe. Superclusters provide an ideal environment to study
structure formation and to search for the emission of the
intergalactic medium such as cosmic filaments and WHIM. In this work,
we present the largest-to-date catalog of X-ray-selected superclusters
identified in the first SRG/eROSITA All-Sky Survey (eRASS1). By
applying the Friends-of-Friends (FoF) method on the galaxy clusters
detected in eRASS1, we identified 1338 supercluster systems in the
western Galactic hemisphere up to redshift 0.8, including 818 cluster
pairs and 520 rich superclusters with ≥3 members. The most massive
and richest supercluster system is the Shapley supercluster at
redshift 0.05 with 45 members and a total mass of
2.58±0.51x1016M☉. The most extensive system has a projected
length of 127Mpc. The sizes of the superclusters we identified in
this work are comparable to the structures found with galaxy survey
data. We also found a good association between the eRASS1
superclusters and the large-scale structures formed by optical
galaxies. We note that 3948 clusters, corresponding to 45% of the
cluster sample, were identified as supercluster members. The
reliability of each supercluster was estimated by considering the
uncertainties in the redshifts of the galaxy clusters and the peculiar
velocities of clusters. Furthermore, 63% of the systems have a
reliability larger than 0.7. The eRASS1 supercluster catalog provided
in this work represents the most extensive sample of superclusters
selected in the X-ray band in terms of the unprecedented sample
volume, sky coverage, redshift range, the availability of X-ray
properties, and the well-understood selection function of the parent
cluster sample, which enables direct comparisons with numerical
simulations. This legacy catalog will greatly advance our
understanding of superclusters and the cosmic large-scale structure.
Description:
We present in this work the first catalog of superclusters in the
western Galactic hemisphere detected from the eRASS1 survey. We base
our supercluster detection on the optically-confirmed galaxy clusters
detected in eRASS1 (Bulbul et al., 2024, A&A, in prep.).
We identify 1338 supercluster systems up to redshift 0.8, including
818 cluster pairs and 520 rich superclusters with ≥3 members.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 81 1338 General properties of superclusters identified
in eRASS1
table2.dat 110 3948 Properties of member clusters of the eRASS1
superclusters
tablea1.dat 81 929 General properties of superclusters identified
in eRASS1 with overdensity ratio f = 50
tablea2.dat 110 2205 Properties of member clusters of the eRASS1
superclusters identified with overdensity
ratio f = 50
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See also:
J/A+A/682/A34 : SRG/eROSITA all-sky survey catalogs (eRASS1) (Merloni+, 2024)
Y/2024/Feb/45 : eRASS Galaxy clusters and groups in WGH (Bulbul+, 2024)
Byte-by-byte Description of file: table1.dat tablea1.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Supercluster name (1eRASS-SC JHHMM+DDMM)
22- 27 F6.4 --- z Supercluster redshift, computed from the
average of its member clusters
29- 36 F8.4 deg RAdeg Right ascension (J2000)
38- 45 F8.4 deg DEdeg Declination (J2000)
47- 48 I2 --- Mult Multiplicity, defined as the number of
member clusters
50- 56 F7.3 10+14Msun Mtot Total mass
58- 63 F6.3 10+14Msun e_Mtot 1 sigma uncertainty in Mtot
65- 68 F4.2 --- Rel Reliability
70- 74 F5.2 Mpc Dmem Average distance of supercluster members
to the center
76- 81 F6.2 Mpc Lproj Supercluster length, defined as the largest
distance between its members
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Byte-by-byte Description of file: table2.dat tablea2.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Supercluster name (1eRASS-SC JHHMM+DDMM)
22- 44 A23 --- Cluster Member cluster name (1eRASS JHHMMSS.s+DDMMSS)
46- 51 F6.4 --- z Cluster redshift
53- 58 F6.4 --- e_z Uncertainty in cluster redshift
60- 67 F8.4 deg RAdeg Cluster right ascension (J2000)
69- 76 F8.4 deg DEdeg Cluster declination (J2000)
78- 83 F6.3 10+14Msun M500 Cluster M500
85- 89 F5.3 10+14Msun e_M500 1 sigma uncertainty in M500
91- 97 F7.3 10+36J L500 Cluster L500 in 0.2-2.3keV (in 1043erg/s)
99-105 F7.3 10+36J e_L500 1 sigma uncertainty in L500 (in 1043erg/s)
107-110 F4.2 --- Pmemb Membership probability
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Acknowledgements:
Ang Liu, liuang.ou(at)gmail.com
(End) Patricia Vannier [CDS] 20-Feb-2024