MASS-TEMPERATURE RELATION OF GALAXY CLUSTERS: IMPLICATIONS FROM THE OBSERVED LUMINOSITY-TEMPERATURE RELATION AND X-RAY TEMPERATURE FUNCTION

摘要

We derive constraints on the mass-temperature relation of galaxy clusters from their observed luminosity-temperature relation and X-ray temperature function. Adopting the isothermal gas in hydrostatic equilibrium embedded in the universal density profile of dark matter halos, we compute the X-ray luminosity for clusters as a function of their hosting halo mass. We find that in order to reproduce the two observational statistics, the mass-temperature relation is fairly well constrained as T_(gas) = (1.5 ～ 2.0) keV(M_(vir)/ 10~(14) h_(70)~(-1) solar mass)~(0.5～0.55), and a simple self-similar evolution model (T_(gas) ∝ M_(vir)~(2/3)) is strongly disfavored. In the cosmological model that we assume (a ΛCDM universe with Ω_0 = 0.3, λ_0 = 0.7, and h_(70) = 1), the derived mass-temperature relation suggests that the mass fluctuation amplitude erg is 0.7-0.8.