Characterization of ICM Temperature Distributions of 62 Galaxy Clusters with XMM-Newton. (arXiv:1212.2239v1 [astro-ph.CO])

Characterization of ICM Temperature Distributions of 62 Galaxy Clusters with XMM-Newton. (arXiv:1212.2239v1 [astro-ph.CO]):
We measure the intracluster medium temperature distributions for 62 galaxy
clusters in the HIFLUGCS, an X-ray flux-limited sample, with available X-ray
data from XMM-Newton. We search for correlations between the width of the
temperature distributions and other cluster properties, including median
cluster temperature, luminosity, size, presence of a cool core, AGN activity,
and dynamical state. We use a Markov Chain Monte Carlo analysis which models
the ICM as a collection of X-ray emitting smoothed particles of plasma. Each
smoothed particle is given its own set of parameters, including temperature,
spatial position, redshift, size, and emission measure. This allows us to
measure the width of the temperature distribution, median temperature, and
total emission measure of each cluster. We find that none of the clusters have
a temperature width, \sigma_kT, consistent with isothermality.
Counterintuitively, we also find that the temperature distribution widths of
disturbed, non-cool-core, and AGN-free clusters tend to be wider than in other
clusters. A linear fit to \sigma_kT - kT_med finds \sigma_kT ~ 0.20kT_med +
1.08, with an estimated intrinsic scatter of ~ 0.55 keV, demonstrating a large
range in ICM thermal histories.