Nonthermal Pressure in the Outskirts of Abell 2142
  Clumping and turbulence are expected to affect the matter accreted onto the
outskirts of galaxy clusters. To determine their impact on the thermodynamic
properties of Abell 2142 we perform an analysis of the X-ray temperature data
from XMM-Newton via our SuperModel, a state-of-the-art tool for investigating
the astrophysics of the intracluster medium already tested on many individual
clusters (since Cavaliere et al. 2009). Using the gas density profile corrected
for clumpiness derived by Tchernin et al. (2016), we find evidence for the
presence of a nonthermal pressure component required to sustain gravity in the
cluster outskirts of Abell 2142, that amounts to about 30% of the total
pressure at the virial radius. The presence of the nonthermal component implies
the gas fraction to be consistent with the universal value at the virial radius
and the electron thermal pressure profile to be in good agreement with that
inferred from the SZ data. Our results indicate that the presence of gas
clumping and of a nonthermal pressure component are both necessary to recover
the observed physical properties in the cluster outskirts. Moreover, we stress
that an alternative method often exploited in the literature (included Abell
2142) to determine the temperature profile k_BT = P_e/n_e basing on a
combination of the Sunyaev-Zel'dovich (SZ) pressure P_e and of the X-ray
electron density n_e does not allow to highlight the presence of nonthermal
pressure support in the cluster outskirts.
