J/MNRAS/389/1074 LX-σ relation of galaxy clusters (Shen+, 2008)
Radio-loud active galactic nuclei and the LX-σ relation of galaxy
groups and clusters.
Shen S., Kauffmann G., Linden A.V.D., White S.D.M., Best P.N.
<Mon. Not. R. Astron. Soc., 389, 1074-1086 (2008)>
=2008MNRAS.389.1074S 2008MNRAS.389.1074S
ADC_Keywords: Clusters, galaxy ; X-ray sources ; Velocity dispersion
Keywords: galaxies: clusters: general - galaxies: jets
Abstract:
We use the ROSAT All-Sky Survey to study the X-ray properties of a
sample of 625 groups and clusters of galaxies selected from the Sloan
Digital Sky Survey. We stack clusters with similar velocity
dispersions and investigate whether their average X-ray luminosities
and surface brightness profiles vary with the radio activity level of
their central galaxies. We find that at a given value of σ,
clusters with a central radio active galactic nucleus (AGN) have more
concentrated X-ray surface brightness profiles, larger central galaxy
masses and higher X-ray luminosities than clusters with radio-quiet
central galaxies. The enhancement in X-ray luminosity is more than a
factor of 2, is detected with better than 6σ significance and
cannot be explained by X-ray emission from the radio AGN itself. This
difference is largely due to a subpopulation of radio-quiet, high
velocity dispersion clusters with low-mass central galaxies. These
clusters are underluminous at X-ray wavelengths when compared to
otherwise similar clusters where the central galaxy is radio-loud,
more massive, or both.
Description:
We use the RASS to study the X-ray properties of our sample of groups
and clusters. The RASS mapped the sky in the soft X-ray band
(0.1-2.4keV) with exposure time varying between 400 and 40000s,
depending on direction on the sky. The resolution of the RASS images
is 45 arcsec.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 95 159 *Clusters of galaxies individually detected in RASS
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Note on tablea1.dat: Here we list the basic properties of 159 clusters of
galaxies individually detected in RASS.
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See also:
J/AJ/130/968 : SDSS-C4 cluster catalog (Miller+, 2005)
http://www.sdss.org : SDSS Home Page
http://www.ctio.noao.edu/~chrism/C4 : SDSS-C4 Galaxy Cluster Catalog Home Page
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- SDSS-C4 ID of cluster in SDSS C4 cluster catalogue
(Miller et al., Cat. J/AJ/130/968)
6- 14 F9.5 deg RAdeg BCG right ascension (J2000) in decimal degrees
16- 24 F9.5 deg DEdeg BCG declination (J2000) in decimal degrees
26- 33 F8.4 deg RAXdeg ? X-ray centre right ascension (J2000)
in decimal degrees
35- 42 F8.4 deg DEXdeg ? X-ray centre declination (J2000)
in decimal degrees
44- 49 F6.4 --- z Redshift of the BCG
51- 54 F4.1 arcmin R200 Virial radius R200
56- 61 F6.1 km/s sigma Velocity dispersion
63- 68 F6.3 fW/m2 FX Flux within RX in the energy band 0.5-2.0kev
(in 10-12erg/cm2/s)
70- 73 F4.1 arcmin RadX X-ray extension radius RX
75- 79 F5.3 --- Err Fractional error on count rate(flux) within RX
81- 85 F5.3 --- fE Extension correction factor fE (1)
87- 92 F6.3 10+37W LX Bolometric X-ray luminosity after the extension
correction (in 1044erg/s)
94- 95 I2 --- rCl Radio loudness property of BCG (2)
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Note (1): The extension correction factor fE is then defined as
fE=[{Int.0.to.R200}IX(r)rdr]/[{int.0.to.RX}IX(r)rdr]
where IX(R)=I0[1+(R2/Rc2)]^(-3beta+0.5),
I0 is the central surface brightness and Rc is the core radius and
is assumed to be proportional to R200, with
Rc=0.14R200 for radio-loud clusters and
Rc=0.18R200 for radio-quiet clusters.
Note (2): Classification numbered as follows:
1 = clusters with BCG to be radio-loud AGN
0 = clusters with BCG to be radio-quiet
-1 = others clusters
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Oct-2009