J/MNRAS/439/611 X-ray luminosities of SDSS DR7 clusters from RASS (Wang+, 2014)
Measuring the X-ray luminosities of SDSS DR7 clusters from ROSAT All Sky Survey.
Wang L., Yang X., Shen S., Mo H.J., Van Den Bosch F.C., Luo W., Wang Y.,
Lau E.T., Wang Q.D., Kang X., Li R.
<Mon. Not. R. Astron. Soc., 439, 611-622 (2014)>
=2014MNRAS.439..611W 2014MNRAS.439..611W (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; X-ray sources
Keywords: methods: statistical - galaxies: haloes - dark matter -
X-rays: galaxies: clusters
Abstract:
We use ROSAT All Sky Survey broad-band X-ray images and the optical
clusters identified from Sloan Digital Sky Survey Data Release 7 to
estimate the X-ray luminosities around ∼65000 candidate clusters with
masses ≳1013h-1^M☉ based on an optical to X-ray (OTX) code we
develop. We obtain a catalogue with X-ray luminosity for each cluster.
This catalogue contains 817 clusters (473 at redshift z≤0.12) with
signal-to-noise ratio >3 in X-ray detection. We find about 65%
of these X-ray clusters have their most massive member located near
the X-ray flux peak; for the rest 35%, the most massive galaxy
is separated from the X-ray peak, with the separation following a
distribution expected from a Navarro-Frenk-White profile. We
investigate a number of correlations between the optical and X-ray
properties of these X-ray clusters, and find that the cluster X-ray
luminosity is correlated with the stellar mass (luminosity) of the
clusters, as well as with the stellar mass (luminosity) of the central
galaxy and the mass of the halo, but the scatter in these correlations
is large. Comparing the properties of X-ray clusters of similar halo
masses but having different X-ray luminosities, we find that massive
haloes with masses ≳1014h-1M☉ contain a larger fraction of
red satellite galaxies when they are brighter in X-ray. An opposite
trend is found in central galaxies in relative low-mass haloes with
masses ≲1014h-1M☉ where X-ray brighter clusters have
smaller fraction of red central galaxies. Clusters with masses
≳1014h-1M☉ that are strong X-ray emitters contain many more
low-mass satellite galaxies than weak X-ray emitters. These results
are also confirmed by checking X-ray clusters of similar X-ray
luminosities but having different characteristic stellar masses. A
cluster catalogue containing the optical properties of member galaxies
and the X-ray luminosity is available at
http://gax.shao.ac.cn/data/Group.html.
Description:
The optical data used in our analysis are taken from the SDSS galaxy
group catalogues of Yang et al. (2007ApJ...671..153Y 2007ApJ...671..153Y), constructed
using the adaptive halo-based group finder of Yang et al.
(2005MNRAS.356.1293Y 2005MNRAS.356.1293Y), here updated to DR7. The parent galaxy
catalogue is the New York University Value-Added Galaxy Catalog
(NYU-VAGC; Blanton et al. 2005AJ....129.2562B 2005AJ....129.2562B) based on the SDSS DR7
(Abazajian et al. 2009ApJS..182..543A 2009ApJS..182..543A), which contains an independent
set of significantly improved reductions.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 213 64646 SDSS-RASS catalog
--------------------------------------------------------------------------------
See also:
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
IX/29 : ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000)
II/294 : SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+ 2009)
J/MNRAS/292/419 : Cooling flows in 207 clusters of galaxies (White+, 1997)
J/MNRAS/389/1074 : LX-σ relation of galaxy clusters (Shen+, 2008)
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- Group Optical Group ID
8- 13 I6 --- Galaxy Central galaxy ID of this group
15- 21 I7 --- NYUVAGC Central galaxy ID in NYUVAGC catalog (1)
23- 24 I2 --- flagb1 [0/11] multi-z flag b1 (2)
26 I1 --- flagb2 [0/4] multi-z flag b2 (3)
28 I1 --- flagb3 [0/1] multi-z flag b3 (4)
30 I1 --- MSID [1/4] Mass sequence ID for central, the
k-th most massive galaxy in a group, k≤4
32- 40 F9.6 arcmin O-X Offset between the optical galaxy and
X-ray cluster center
42- 50 F9.5 deg RAdeg Right ascension of the X-ray cluster
(J2000)
52- 60 F9.5 deg DEdeg Declination of the X-ray cluster (J2000)
62- 73 F12.9 ct/s CRate X-ray photons count rate (in 0.1-2.4keV)
in detection radius 0.5*r200
75- 85 F11.9 ct/s e_CRate Error for the count rate
87- 90 F4.1 arcmin RX Radius of the extended X-ray source,
here Rx = 0.5*r200
92-103 F12.8 10-15W/m2 Flux X-ray flux
105-115 F11.8 10+37W LX X-ray luminosity of a cluster in 0.1-2.4keV
117-127 F11.8 10+37W LB Bolometric luminosity (derived from LX)
129-138 F10.8 --- ExtCorr beta model correction factor for the
'missing' fraction of the total projected
source emission (ext_corr)
140-152 F13.8 km/s sigma Velocity dispersion derived from the
optical halo mass (5)
154-156 I3 --- Ngal Number of galaxies in the group
158-161 F4.2 keV T Gas temperature of the group derived from
the velocity dispersion sigma (6)
163-170 E8.3 [cm-2] logNH Galactic hydrogen column density
172-177 F6.1 s Aexpo Average exposure time on the detection
179-187 F9.7 --- z Optical spectroscopic redshift of the
central galaxy
189-196 F8.5 arcmin Apr500 Aperture of r500
198-205 F8.5 --- S/N Signal to noise ratio of the X-ray
detection
207-213 F7.5 --- fmulti Flux fraction of a X-ray source in a
multi-cluster detection, see Eq.5 in
this paper
--------------------------------------------------------------------------------
Note (1): see Yang et al. 2007ApJ...671..153Y 2007ApJ...671..153Y, 2008ApJ...676..248Y 2008ApJ...676..248Y,
2009ApJ...695..900Y 2009ApJ...695..900Y for detail.
Note (2): Multi-z flag b1,
b1 = 0 means clean (or isolated) detection,
fmulti = 1.0, the nearest neighbor detection is farther than 0.5*r200,
b1 = 1,2,3...n refers to there are n for the first nearest neighbor detections
within 0.5*r200, and ordered by their redshift z
Note (3): multi-z flag b2,
for the i-th cluster (or group or detection) with b1=j+1,
if b2/=0 then the former (i-1)th cluster (has lower redshift) with b1=j
locate in 0.5*r200 of the i-th cluster.
Note (4): multi-z flag b3, b3(i+1)=1 means the i-th cluster has larger
min{Rx,0.5*r200} than the former (i-1)th cluster (has lower redshift).
Note (5): see Yang et al. 2007ApJ...671..153Y 2007ApJ...671..153Y, Eq. 6.
Note (6): see White et al., 1997MNRAS.292..419W 1997MNRAS.292..419W, Cat. J/MNRAS/292/419 or
Shen et al., 2008MNRAS.389.1074S 2008MNRAS.389.1074S, Cat. J/MNRAS/389/1074, Eq. 2.
--------------------------------------------------------------------------------
History:
Copied at http://gax.shao.ac.cn/data/Group.html
(End) Patricia Vannier [CDS] 09-Jul-2015