A Chandra Study of Radial Temperature Profiles of the Intra-Cluster
  Medium in 50 Galaxy Clusters
  In order to investigate the spatial distribution of the ICM temperature in
galaxy clusters in a quantitative way and probe the physics behind, we analyze
the X-ray spectra of a sample of 50 galaxy clusters, which were observed with
the Chandra ACIS instrument in the past 15 years, and measure the radial
temperature profiles out to $0.45r_{500}$. We construct a physical model that
takes into account the effects of gravitational heating, thermal history (such
as radiative cooling, AGN feedback, and thermal conduction) and work done via
gas compression, and use it to fit the observed temperature profiles by running
Bayesian regressions. The results show that in all cases our model provides an
acceptable fit at the 68% confidence level. To further validate this model we
select nine clusters that have been observed with both Chandra (out to $\gtrsim
0.3r_{500}$) and Suzaku (out to $\gtrsim 1.5r_{500}$), fit their Chandra
spectra with our model, and compare the extrapolation of the best-fits with the
Suzaku measurements. We find that the model profiles agree with the Suzaku
results very well in seven clusters. In the rest two clusters the difference
between the model and observation is possibly caused by local thermal
substructures. Our study also implies that for most of the clusters the
assumption of hydrostatic equilibrium is safe out to at least $0.5r_{500}$, and
the non-gravitational interactions between dark matter and its luminous
counterpart is consistent with zero.
