X-Ray Emission from Optically Selected Galaxy Groups

Details X-Ray Emission from Optically Selected Galaxy Groups X-Ray Emission from Optically Selected Galaxy Groups

Jul 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997apj...483...68m&link_type=abstract

Astrophysical Journal v.483, p.68

Astronomy and Astrophysics

Astronomy

38

Galaxies: Clusters: General, X-Rays: Galaxies

Scientific paper

We use the ROSAT All Sky Survey to compute X-ray luminosities for an optically selected sample of 32 galaxy groups. The groups were identified by an objective algorithm as three-dimensional density enhancements in the magnitude-limited Center for Astrophysics Redshift Survey. The sample of groups includes five poor Abell clusters. We use the optical galaxy positions to limit the sky area in which we search for the faint, extended X-ray emission from the groups. Nine of the groups have significant diffuse X-ray emission, with 0.5--2.0 keV luminosities in the range 0.12--1.6 h-2 x 1043 ergs s-1, where we use h = H0/(50 km s-1 Mpc-1). Among these nine groups, only three are Abell clusters. For the remaining 23 systems we compute 3 sigma upper limits. The relationship between the X-ray luminosities and the radial velocity dispersions differs significantly from that for rich clusters. We find L^{{group}}X~ sigma ^{1.56+/-0.25} , whereas L^{{cluster}}X~ sigma 4 . This shallow slope is consistent with models in which intragroup gas concentrated around individual galaxies makes a substantial contribution to the extended X-ray emission. Previous work suggests that in this case LX ~ sigma 1.6. The X-ray/optical luminosity relationship for these systems is LX~L^{1.06+/-0.11}B , physically consistent with the shallow LX - sigma relation. There is some correlation (Kendall's tau = 0.4, P = 0.1) between the fraction of member ellipticals and LX.

Affiliated with

Also associated with

No associations

Rating

X-Ray Emission from Optically Selected Galaxy Groups does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with X-Ray Emission from Optically Selected Galaxy Groups, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-Ray Emission from Optically Selected Galaxy Groups will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1184763