The LX-M relation of clusters of galaxies

Abstract

We present a new measurement of the scaling relation between X-ray luminosity and total mass for 17000 galaxy clusters in the maxBCG cluster sample. Stacking subsamples within fixed ranges of optical richness, N200, we measure the mean 0.1-2.4 keV X-ray luminosity, , we measure the mean 0.1-2.4 keV X-ray luminosity, X>, from the ROSAT All-Sky Survey. The mean mass, >, from the ROSAT All-Sky Survey. The mean mass, 200>, is measured from weak gravitational lensing of SDSS background galaxies. For 9 >, is measured from weak gravitational lensing of SDSS background galaxies. For 9 200 X>/1042h-2ergs-1 = [12.6+1.4-1.3(stat) +/- 1.6(sys)]((stat) +/- 1.6(sys)](200>/1014h-1Msolar)1.65+/-0.13. The slope agrees to within 10 per cent with previous estimates based on X-ray selected catalogues, implying that the covariance in LX and N200 at a fixed halo mass is not large. The luminosity intercept is 30 per cent, or 2?, lower than that determined from the X-ray flux-limited sample of Reiprich & Böhringer, 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. using a model for the statistical correspondence between clusters and haloes in a WMAP3 cosmology with power spectrum normalization ?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 a fixed mass.