J/MNRAS/429/3272 REFLEX II flux-limited supercluster sample (Chon+, 2013)
The extended ROSAT-ESO flux-limited X-ray galaxy cluster survey (REFLEX II).
III. Construction of the first flux-limited supercluster sample.
Chon G., Bohringer H., Nowak N.
<Mon. Not. R. Astron. Soc., 429, 3272-3287 (2013)>
=2013MNRAS.429.3272C 2013MNRAS.429.3272C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; X-ray sources
Keywords: galaxies: clusters: general; large-scale structure of Universe
x-rays: galaxies: clusters
Abstract:
We present the first supercluster catalogue constructed with the extended
ROSAT-ESO Flux-Limited X-ray (REFLEX II) Galaxy Cluster survey data,
which comprises 919 X-ray selected galaxy clusters with a flux limit
of 1.8x10-12erg/s/cm2. Based on this cluster catalogue we
construct a supercluster catalogue using a friends-of-friends
algorithm with a linking length depending on the (local) cluster
density, which thus varies with redshift. The resulting catalogue
comprises 164 superclusters at redshift z≤0.4.
The choice of the linking length in the friends-of-friends method
modifies the properties of the superclusters. We study the properties
of different catalogues such as the distributions of the redshift,
extent and multiplicity by varying the choice of parameters. In
addition to the supercluster catalogue for the entire REFLEX II
sample, we compile a large volume-limited cluster sample from REFLEX
II with the redshift and luminosity constraints of z≤0.1 and
LX≥5x1043erg/s. With this catalogue we construct a volume-limited
sample of superclusters. This sample is built with a homogeneous
linking length, and hence selects effectively the same type of
superclusters. By increasing the luminosity cut we can build a
hierarchical tree structure of the volume-limited samples, where
systems at the top of the tree are only formed via the most luminous
clusters. This allows us to test if the same superclusters are found
when only the most luminous clusters are visible, comparable to the
situation at higher redshift in the REFLEX II sample. We find that the
selection of superclusters is very robust, independent of the
luminosity cut, and the contamination of spurious superclusters among
cluster pairs is expected to be small.
Numerical simulations and observations of the substructure of clusters
suggest that regions of high cluster number density provide an
astrophysically different environment for galaxy clusters, where the
mass function and X-ray luminosity function are shifted to higher
cut-off values and an increased merger rate may also boost some of the
cluster X-ray luminosities. We therefore compare the X-ray luminosity
function for the clusters in superclusters with that for the field
clusters with the flux- and volume-limited catalogues. The results
mildly support the theoretical suggestion of a top-heavy X-ray
luminosity function of galaxy clusters in regions of high cluster
density.
Description:
This catalogue, constructed from the REFLEX II survey, is the first
supercluster catalogue based on a complete and homogeneous X-ray
flux-limited cluster sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 73 31 List of the volume-limited superclusters (LX,0)
tableb1.dat 64 164 List of the REFLEX II superclusters constructed
with mean cluster density f=10
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See also:
J/A+A/555/A30 : REFLEX II. Properties of the survey (Boehringer+ 2013)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [RXSC]
6- 15 A10 --- RXSC Supercluster RXSC designation (JHHMM+DDMM)
17- 23 F7.3 deg RAdeg Supercluster right ascension (J2000) (1)
25- 31 F7.3 deg DEdeg Supercluster declination (J2000) (1)
33- 38 F6.4 --- zSC Supercluster redshift (1)
40- 44 F5.2 Mpc Rmax Half the maximum extent between clusters in
the supercluster
46- 51 F6.3 10+37W/S LX Total X-ray luminosity (2)
53- 54 I2 --- Mul Number of member clusters
56- 64 A9 --- ID Corresponding supercluster ID(s) in
tableb1.dat (3)
66- 67 A2 --- n_ID [+1] Note on ID (4)
69- 73 A5 --- f50 Flag for the presence in mean cluster density
f=50 catalog (5)
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Note (1): The position and redshifts are mass-weighted by the member clusters
as described in the text.
Note (2): LX is the sum of all member cluster luminosities.
Note (3): ID of the full REFLEX II superclusters.
Note (4): +1 means that the superclusters in the VLS acquired a new cluster
member
Note (5): indicates if the supercluster was found in the mean cluster density
f=50 catalog.
Y = marks the existence of the supercluster in the f=50 catalog
Y-x = x number of clusters that were missing in the f=50 catalog
Y/x = the supercluster was divided into x number of superclusters
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Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [RXSC]
6- 15 A10 --- RXSC Supercluster RXSC designation (JHHMM+DDMM)
17- 23 F7.3 deg RAdeg Supercluster right ascension (J2000) (1)
25- 31 F7.3 deg DEdeg Supercluster declination (J2000) (1)
33- 38 F6.4 --- zSC Supercluster redshift (1)
40- 44 F5.2 Mpc Rmax Half the maximum extent between clusters in
the supercluster
46- 51 F6.3 10+37W/S LX Total X-ray luminosity (2)
53- 54 I2 --- Mul Number of member clusters
56- 60 A5 --- f50 Flag for the presence in f=50 catalog (3)
62- 64 I3 --- ID Sequential number of the supercluster
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Note (1): The positions and redshifts are calculated with an X-ray LX weighting
of member clusters as described in the text.
Note (2): LX is the sum of cluster luminosities.
Note (3): indicates if the supercluster found in the mean cluster density f=10
catalogue was found in the mean cluster density f=50 catalogue.
Y = marks the existence of the supercluster in the f=50 catalog
Y-x = x number of clusters that were missing in the f=50 catalog
Y/x = the supercluster was divided into x number of superclusters
The catalogue constructed with f=50 contains no new superclusters compared to
the main catalogue.
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History:
From electronic version of the journal
References:
Chon et al., Paper I 2012A&A...538A..35C 2012A&A...538A..35C
Boehringer et al., Paper II 2013A&A...555A..30B 2013A&A...555A..30B, J/A+A/555/A30
Boehringer et al., Paper IV 2014A&A...570A..31B 2014A&A...570A..31B
Boehringer et al., Paper V 2015A&A...574A..26B 2015A&A...574A..26B
Boehringer et al., Paper VI 2015A&A...574L...8B 2015A&A...574L...8B
(End) Patricia Vannier [CDS] 30-Jan-2017