The L_X-M relation of Clusters of Galaxies

Technical Report · Fri May 16 00:00:00 EDT 2008

DOI:https://doi.org/10.2172/928354· OSTI ID:928354

Rykoff, E S; Evrard, A E; McKay, T A; Becker, M R; Johnston, D E; Koester, B P; Nord, B; Rozo, E; Sheldon, E S; Stanek, R; Wechsler, R H

We present a new measurement of the scaling relation between X-ray luminosity and total mass for 17,000 galaxy clusters in the maxBCG cluster sample. Stacking sub-samples within fixed ranges of optical richness, N200, we measure the mean 0.1-2.4 keV X-ray luminosity, <L{sub X}>, from the ROSAT All-Sky Survey. The mean mass, <M{sub 200}>, is measured from weak gravitational lensing of SDSS background galaxies (Johnston et al. 2007). For 9 {le} N{sub 200} < 200, the data are well fit by a power-law, <L{sub X}>/10{sup 42} h{sup -2} ergs{sup -1} = (12.6{sub -1.3}{sup +1.4}(stat) {+-} 1.6 (sys)) (<M{sub 200}>/10{sup 14} h{sup -1} M{sub {circle_dot}}){sup 1.65{+-}0.13}. The slope agrees to within 10% with previous estimates based on X-ray selected catalogs, implying that the covariance in L{sub X} and N{sub 200} at fixed halo mass is not large. The luminosity intercept is 30%, or 2{sigma}, lower than determined from the X-ray flux-limited sample of Reiprich & Boehringer (2002), assuming hydrostatic equilibrium. This slight difference could arise from a combination of Malmquist bias and/or systematic error in hydrostatic mass estimates, both of which are expected. The intercept agrees with that derived by Stanek et al. (2006) using a model for the statistical correspondence between clusters and halos in a WMAP3 cosmology with power spectrum normalization {sigma}{sub 8} = 0.85. Similar exercises applied to future data sets will allow constraints on the covariance among optical and hot gas properties of clusters at fixed mass.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 928354
• Report Number(s): SLAC-PUB-13238; arXiv:0802.1069
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
Astrophysics
ASTRO
COSMOLOGY
GALAXIES
GALAXY CLUSTERS
HYDROSTATICS
LUMINOSITY