February 10, 1999
We examine the relationship between the mass and x-ray gas temperature of galaxy clusters using data drawn from the literature. Simple theoretical arguments suggest that the mass of a cluster is related to the x-ray temperature as $M \propto T_x^{3/2}$. Virial theorem mass estimates based on cluster galaxy velocity dispersions seem to be accurately described by this scaling with a normalization consistent with that predicted by the simulations of Evrard, Metzler, & Navarro (1996). X-ray mass estimates which employ spatially resolved temperature profiles also follow a $T_x^{3/2}$ scaling although with a normalization about 40% lower than that of the fit to the virial masses. However, the isothermal $\beta$-model and x-ray surface brightness deprojection masses follow a steeper $\propto T_x^{1.8-2.0}$ scaling. The steepness of the isothermal estimates is due to their implicitly assumed dark matter density profile of $\rho(r) \propto r^{-2}$ at large radii while observations and simulations suggest that clusters follow steeper profiles (e.g., $\rho(r) \propto r^{-2.4}$).
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January 31, 2001
We present a new investigation of the mass-temperature (\MTrelation) relation of 22 nearby clusters based on the analysis of their ROSAT X-ray surface brightness profiles ($S_{X}(r)$) and their ASCA emission weighted temperatures. Two methods of the cluster mass estimations are employed and their results are compared: (1) the conventional $\beta$ model for gas distribution along with the isothermal and hydrostatic equilibrium assumptions, and (2) the NFW profile for dark matt...
May 2, 2001
Combining conservation of energy throughout nearly-spherical collapse of galaxy clusters with the virial theorem, we derive the mass-temperature relation for X-ray clusters of galaxies $T=CM^{2/3}$. The normalization factor $C$ and the scatter of the relation are determined from first principles with the additional assumption of initial Gaussian random field. We are also able to reproduce the recently observed break in the M-T relation at $T \sim 3 \keV$, based on the scatter...
February 23, 1998
A tight mass-temperature relation, M(r)/r ~ T_X, is expected in most cosmological models if clusters of galaxies are homologous and the intracluster gas is in global equilibrium with the dark matter. We here calibrate this relation using 8 clusters with well-defined global temperatures measured with ASCA and masses inferred from weak and strong gravitational lensing. The surface lensing masses are deprojected in accordance with N-body simulations and analytic results. The dat...
November 18, 1999
We calibrate the galaxy cluster mass - temperature relation using the temperature profiles of intracluster gas observed with ASCA (for hot clusters) and ROSAT (for cool groups). Our sample consists of apparently relaxed clusters for which the total masses are derived assuming hydrostatic equilibrium. The sample provides data on cluster X-ray emission-weighted cooling flow-corrected temperatures and total masses up to r_1000. The resulting M-T scaling in the 1-10 keV temperatu...
February 14, 2011
We present a detailed study of scaling relations between total cluster mass and three mass proxies based on X-ray observables: temperature of the intra-cluster medium, gas mass and the product of the two, Y_X. Our analysis is based on two sets of high-resolution hydrodynamical simulations performed with the TreePM-SPH GADGET code. The first set includes about 140 clusters with masses above 5x10^13 M_sun/h (30 having mass above 10^15 M_sun/h), that have been simulated with (i)...
October 10, 2000
We present results on the total mass and temperature determination using two samples of clusters of galaxies. One sample is constructed with emphasis on the completeness of the sample, while the advantage of the other is the use of the temperature profiles, derived with ASCA. We obtain remarkably similar fits to the M-T relation for both samples, with the normalization and the slope significantly different from both prediction of self-similar collapse and hydrodynamical simul...
December 12, 2002
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 very tightly c...
February 10, 2005
Using a sample of ten nearby (z< 0.15), relaxed galaxy clusters in the temperature range [2-9] keV, we have investigated the scaling relation between the mass at various density contrasts (delta=2500,1000,500,200) and the cluster temperature. The masses are derived from NFW-type model fits to mass profiles, obtained under the hydrostatic assumption using precise measurements, with XMM, at least down to delta=1000. The logarithmic slope of the M-T relation is well constrained ...
December 21, 2009
We present the mass-X-ray observable scaling relationships for clusters of galaxies using the XMM-Newton cluster catalog of Snowden et al. Our results are roughly consistent with previous observational and theoretical work, with one major exception. We find 2-3 times the scatter around the best fit mass scaling relationships as expected from cluster simulations or seen in other observational studies. We suggest that this is a consequence of using hydrostatic mass, as opposed ...
November 4, 2003
There has been extensive recent progress in X-ray observations of clusters of galaxies with the analysis of the entire ASCA database and recent new results from Beppo-SAX, Chandra, and XMM-Newton. The temperature profiles of most clusters are isothermal from 0.05--0.6 virial radii, contrary to theoretical expectations and early results from ASCA. Similarly, the abundance profiles of Fe are roughly constant outside the central regions. The luminosity-temperature relation for a...