The Halo Mass–Temperature Relation for Clusters, Groups, and Galaxies

Abstract

The halo mass–temperature ( M – T ) relation for a sample of 216 galaxy clusters, groups, and individual galaxies observed by the Chandra X-ray Observatory is presented. Using accurate spectral measurements of their hot atmospheres, we derive the M – T relation for systems with temperatures ranging between 0.4 and 15.0 keV. We measure the total masses of the clusters, groups, and galaxies at radius R 2500 , finding that the M 2500 ∝ T α relation follows a power law with α = 1.65 ± 0.06. Our relation agrees with recent lensing studies of the M – T relation at R 200 and is consistent with self-similar theoretical predictions and recent simulations. This agreement indicates that the M – T relation is weakly affected by nongravitational heating processes. Using lensing masses within R 200 we find M 200 – T follows a power law with a slope of 1.61 ± 0.19, consistent with the M 2500 – T relation. No evidence for a break or slope change is found in either relation. Potential biases associated with sample selection, evolution, and the assumption of hydrostatic equilibrium that may affect the scaling are examined. No significant impacts attributable to these biases are found. Non-cool-core clusters and early spirals produce higher scatter in the M – T relation than cool-core clusters and elliptical galaxies.