Observational Tests of the Mass-Temperature Relation for Galaxy Clusters

Precision cosmology studies based on wide-field surveys of galaxy clusters benefit from constraints on intrinsic scatter in mass-observable relationships. In principle, two-parameter models combining direct measurements of galaxy cluster structural variation with mass proxies such as X-ray luminosity and temperature can be used to constrain scatter in the relationship between the mass proxy and the cluster's halo mass and to measure the redshift evolution of that scatter. One...

An X-ray survey with the XMM-Newton telescope, XMM-XXL, has identified hundreds of galaxy groups and clusters in two 25 deg$^2$ fields. Combining spectroscopic and X-ray observations in one field, we determine how the kinetic energy of galaxies scales with hot gas temperature and also, by imposing prior constraints on the relative energies of galaxies and dark matter, infer a power-law scaling of total mass with temperature. Our goals are: i) to determine parameters of the sc...

We examine the relations linking mass, X-ray temperature and bolometric luminosity for a sample of luminous, relatively relaxed clusters of galaxies observed with the Chandra Observatory, for which independent confirmation of the mass results is available from gravitational lensing studies. Within radii corresponding to a fixed overdensity Delta = 2500 with respect to the critical density at the redshifts of the clusters, the observed temperature profiles, scaled in units of ...

We use the RASS-SDSS galaxy cluster sample to compare the quality of optical and X-ray luminosities as predictors of other cluster properties such as their masses, temperatures, and velocity dispersions. We use the SDSS spectroscopic data to estimate the velocity dispersions and the virial masses of a subsample of 69 clusters within r_{500} and r_{200}. The ASCA temperature of the intra-cluster medium, T_X, is retrieved from the literature for a subsample of 49 clusters. For ...

(Abridged) We examine the X-ray luminosity scaling relations of 31 nearby galaxy clusters from the Representative XMM-Newton Cluster Structure Survey (REXCESS). The objects are selected in X-ray luminosity only, optimally sampling the cluster luminosity function; temperatures range from 2 to 9 keV and there is no bias toward any particular morphological type. Pertinent values are extracted in an aperture corresponding to R_500, estimated using the tight correlation between Y_...

We derive correlations between X-ray temperature, luminosity, and gas mass for a sample of 22 distant, z>0.4, galaxy clusters observed with Chandra. We detect evolution in all three correlations between z>0.4 and the present epoch. In particular, in the Omega=0.3, Lambda=0.7 cosmology, the luminosity corresponding to a fixed temperature scales approximately as (1+z)**(1.5+-0.3); the gas mass for a fixed luminosity scales as (1+z)**(-1.8+-0.4); and the gas mass for a fixed tem...

We have assembled a large sample of virialized systems, comprising 66 galaxy clusters, groups and elliptical galaxies with high quality X-ray data. To each system we have fitted analytical profiles describing the gas density and temperature variation with radius, corrected for the effects of central gas cooling. We present an analysis of the scaling properties of these systems and focus in this paper on the gas distribution and M-T relation. In addition to clusters and groups...

Observations and numerical simulations have shown that the relation between the mass scaled with the critical density of the universe and the X-ray temperature of galaxy clusters is approximately represented by $M_\Delta \propto T_X^{3/2}$ (e.g. $\Delta=500$). This relation is often interpreted as evidence that clusters are in virial equilibrium. However, the recently discovered fundamental plane (FP) of clusters indicates that the temperature of clusters primarily depends on...

In this Letter we present the radial temperature profiles of three X-ray clusters (A119, A2255 and A2256) reconstructed from a combination of the X-ray surface brightness measurements and the universal density profile as the underlying dark matter distribution. Our algorithm is based on the hydrostatic equilibrium for intracluster gas and the universality of the total baryon fraction within the virial radius. The scaled temperature profiles of these three clusters appear to b...

We present some of the results of an ongoing collaboration to sudy the dynamical properties of galaxy clusters by means of high resolution adiabatic SPH cosmological simulations. Results from our numerical clusters have been tested against analytical models often used in X-ray observations: $\beta$ model (isothermal and polytropic) and those based on universal dark matter profiles. We find a universal temperature profile, in agreement with AMR gasdynamical simulations of gala...