J/MNRAS/449/199 Relaxed galaxy clusters sample (Mantz+, 2015)
Cosmology and astrophysics from relaxed galaxy clusters. I. Sample selection.
Mantz A.B., Allen S.W., Morris R.G., Schmidt R.W., von der Linden A.,
Urban O.
<Mon. Not. R. Astron. Soc., 449, 199-219 (2015)>
=2015MNRAS.449..199M 2015MNRAS.449..199M (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; X-ray sources
Keywords: galaxies: clusters: general - X-rays: galaxies: clusters
Abstract:
This is the first in a series of papers studying the astrophysics and
cosmology of massive, dynamically relaxed galaxy clusters. Here we
present a new, automated method for identifying relaxed clusters based
on their morphologies in X-ray imaging data. While broadly similar to
others in the literature, the morphological quantities that we measure
are specifically designed to provide a fair basis for comparison
across a range of data quality and cluster redshifts, to be robust
against missing data due to point source masks and gaps between
detectors, and to avoid strong assumptions about the cosmological
background and cluster masses. Based on three morphological indicators
- symmetry, peakiness, and alignment - we develop the
symmetry-peakiness-alignment (SPA) criterion for relaxation. This
analysis was applied to a large sample of cluster observations from
the Chandra and ROSAT archives. Of the 361 clusters which received the
SPA treatment, 57 (16 per cent) were subsequently found to be relaxed
according to our criterion. We compare our measurements to similar
estimators in the literature, as well as projected ellipticity and
other image measures, and comment on trends in the relaxed cluster
fraction with redshift, temperature, and survey selection method. Code
implementing our morphological analysis will be made available on the
web (http://www.slac.stanford.edu/amantz/work/morph14/).
Description:
For this work, we analysed data for a large sample of galaxy clusters
which have archival Chandra observations (as of 2013 February 1).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 114 361 Results of our morphological analysis
tablea1.dat 58 691 Chandra data used in this work
tablea2.dat 43 90 ROSAT data used in this work
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See also:
J/MNRAS/301/881 : The ROSAT brightest cluster sample - I. (Ebeling+, 1998)
J/A+A/425/367 : REFLEX Galaxy Cluster Survey catalogue (Boehringer+, 2004)
J/ApJ/580/774 : X-ray galaxy clusters behind the Milky way (Ebeling+, 2002)
J/ApJ/662/224 : Second CIZA subsample (Kocevski+, 2007)
J/ApJS/172/561 : The 400d cluster Survey (Burenin+, 2007)
J/ApJS/216/27 : Galaxy clusters discovered in SPT-SZ survey (Bleem+, 2015)
J/ApJS/199/25 : CLASH sources for MACS1149.6+2223 (Postman+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Cat Catalog that each cluster was drawn from (1)
4- 20 A17 --- Cluster Cluster name (Prefixes that are implied by
column "Cat" have been suppressed)
22 A1 --- Obs [CR] Observatory used to produce the listed
results, either Chandra (C) or ROSAT (R)
24- 27 A4 --- Flag [aclpf ] Flags indicating whether a cluster is
part of some samples (2)
29- 34 F6.3 --- S ? Symmetry measurement (3)
36- 40 F5.3 --- e_S ? rms uncertainty on S (3)
42- 47 F6.3 --- P ? Peakiness measurement (3)
49- 53 F5.3 --- e_P ? rms uncertainty on P (3)
55- 59 F5.2 --- a ? Alignment measurement (3)
61- 64 F4.2 --- e_a ? rms uncertainty on a (3)
66 A1 --- Rel [Y] Indicates whether the cluster is relaxed
according to the SPA criterion introduced
in Section 5.4.
68- 72 F5.3 --- Ell ? Mean ellipticity of the isophotes employed
in our analysis
74- 78 F5.3 --- e_Ell ? rms uncertainty on Ell
80- 87 F8.4 deg RAdeg Right ascension (J2000) of the global center
measured from the X-ray analysis
(without bootstrapping)
89- 96 F8.4 deg DEdeg Declination (J2000) of the global center
measured from the X-ray analysis
(without bootstrapping)
98-105 F8.4 deg RABdeg ? Right ascension (J2000) of the BCG
identified in Section 5.2
107-114 F8.4 deg DEBdeg ? Declination (J2000) of the BCG identified
in Section 5.2
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Note (1): Catalog abbreviations as follows:
B = BCS, ROSAT Brightest Cluster Sample
(Ebeling et al., 1998, Cat. J/MNRAS/301/881)
R = REFLEX, ROSAT-ESO Flux Limited X-ray cluster sample
(Bohringer et al., 2004, Cat. J/A+A/425/367)
C = CIZA, Clusters in the Zone of Avoidance,
Ebeling, Mullis & Tully 2002, Cat. J/ApJ/580/774;
Kocevski et al., 2007, Cat. J/ApJ/662/224)
M = MACS, Massive Cluster Survey (Ebeling, Edge & Henry, 2001ApJ...553..668E 2001ApJ...553..668E,
Ebeling et al., 2007ApJ...661L..33E 2007ApJ...661L..33E, 2010MNRAS.407...83E 2010MNRAS.407...83E)
6 = 400d, 400 square degree ROSAT survey
(Burenin et al., 2007, Cat. J/ApJS/172/561)
S = SPT, South Pole Telescope cluster survey (Bleem et al., 2015,
Cat. J/ApJS/216/27) catalogs
* = none of the above
A * appended to a catalog identifier means that the cluster can be found in
the indicated sample, but does not satisfy the X-ray luminosity
threshold normally applied in Section 2.
Note (2): Samples flag as follows (see Sections 5.5-5.7):
a = A08, Allen et al. (2008MNRAS.383..879A 2008MNRAS.383..879A)
c = CLASH relaxed (Postman et al., Cat. J/ApJS/199/25)
l = LoCuSS low centroid variance (Martino et al., 2014MNRAS.443.2342M 2014MNRAS.443.2342M)
p = CCCP low central entropy (Mahdavi et al., 2013ApJ...767..116M 2013ApJ...767..116M)
f = cluster is used in Paper II (Mantz et al., 2014MNRAS.440.2077M 2014MNRAS.440.2077M)
Note (3): Symmetry, peakiness and alignment measurements. Note that some or all
may be missing, dependent on data quality (see Section 5). In general, when
the data were inadequate to measure s and a, we did not carry through the
bootstrapping procedure to obtain uncertainties on p.
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Cluster Cluster name (ordered as in Table 1)
19- 27 A9 --- ObsID observation ID
29- 38 A10 "date" Obs.date Date of observation
40 A1 --- B [A-E] Blank-sky background epoch
42 A1 --- D [I/S] Detector (ACIS-I or ACIS-S);
44- 45 A2 --- M [F V*] Data mode (VFAINT or FAINT;
V* indicates VFAINT reduced in FAINT mode)
47- 51 F5.1 ks ExpTime Nominal exposure length
53- 57 F5.1 ks GTI ? Good time interval remaining after filtering
58 A1 --- n_GTI [E] E indicates an excluded exposure
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Cluster Cluster name
17- 27 A11 --- Obs.ID Observation ID
29- 38 A10 "date" Obs.date Date of observation
40- 43 F4.1 ks ExpTime Nominal exposure length
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Jan-2016