A complete view of the outskirts of the Coma cluster
  We present a new extended XMM-Newton mosaic of the nearby Coma cluster, which
covers the cluster out to the virial radius with nearly complete azimuthal
coverage. This large mosaic is combined with the Planck Sunyaev Zel'dovich
effect observations to recover the thermodynamic properties of the intracluster
medium in an azimuthally averaged profile and 36 angular sectors, producing the
highest spatial resolution view of the thermodynamics of the outskirts of a
galaxy cluster in its entirety. Beyond $r_{500}$, our clumping corrected
entropy measurements along the less disturbed directions are statistically
consistent with the power-law entropy profile predicted by non-radiative
simulations, and the gas mass fraction agrees with the mean cosmic baryon
fraction. However, there is a clear entropy deficit in the outskirts to the
southwest, coinciding with where Coma connects to a cosmic web filament which
joins it to Abell 1367. The low entropy to the southwest extends from
0.5-1.0$r_{200}$, and is consistent with what is expected from simulations of a
filamentary gas stream penetrating into the cluster as it continues to accrete
matter from the cosmic web. We also find that the radial profiles of the
recovered quantities become increasingly asymmetric in the outskirts,
particularly along the more disturbed directions, consistent with the
predictions of cosmological simulations.
