Thermodynamics of the Coma Cluster Outskirts
  We present results from a large mosaic of Suzaku observations of the Coma
Cluster, the nearest and X-ray brightest hot, dynamically active, non-cool core
system, focusing on the thermodynamic properties of the ICM on large scales.
For azimuths not aligned with an infalling subcluster towards the southwest,
our measured temperature and X-ray brightness profiles exhibit broadly
consistent radial trends, with the temperature decreasing from about 8.5 keV at
the cluster center to about 2 keV at a radius of 2 Mpc, which is the edge of
our detection limit. The SW merger significantly boosts the surface brightness,
allowing us to detect X-ray emission out to ~2.2 Mpc along this direction.
Apart from the southwestern infalling subcluster, the surface brightness
profiles show multiple edges around radii of 30-40 arcmin. The azimuthally
averaged temperature profile, as well as the deprojected density and pressure
profiles, all show a sharp drop consistent with an outward propagating shock
front located at 40 arcmin, corresponding to the outermost edge of the giant
radio halo observed at 352 MHz with the WSRT. The shock front may be powering
this radio emission. A clear entropy excess inside of r_500 reflects the
violent merging events linked with these morphological features. Beyond r_500,
the entropy profiles of the Coma Cluster along the relatively relaxed
directions are consistent with the power-law behavior expected from simple
models of gravitational large-scale structure formation. The pressure is also
in agreement at these radii with the expected values measured from SZ data from
the Planck satellite. However, due to the large uncertainties associated with
the Coma Cluster measurements, we cannot yet exclude an entropy flattening in
this system consistent with that seen in more relaxed cool core clusters.
