GASP XXXIV: Unfolding the thermal side of ram pressure stripping in the
  jellyfish galaxy JO201
  X-ray studies of jellyfish galaxies play a crucial role in understanding the
interactions between the interstellar medium (ISM) and the intracluster medium
(ICM). In this paper, we focused on the jellyfish galaxy JO201. By combining
archival Chandra observations, MUSE H$\alpha$ cubes, and maps of the emission
fraction of the diffuse ionised gas, we investigated both its high energy
spectral properties and the spatial correlation between its X-ray and optical
emissions. The X-ray emission of JO201 is provided by both the Compton thick
AGN (L$_{\text{X}}^{0.5-10 \text{keV}}$=2.7$\cdot$10$^{41}$ erg s$^{-1}$, not
corrected for intrinsic absorption) and an extended component
(L$_{\text{X}}^{0.5-10 \, \text{keV}}\approx$1.9-4.5$\cdot$10$^{41}$ erg
s$^{-1}$) produced by a warm plasma (kT$\approx$1 keV), whose luminosity is
higher than expected from the observed star formation
(L$_{\text{X}}\sim$3.8$\cdot10^{40}$ erg s$^{-1}$). The spectral analysis
showed that the X-ray emission is consistent with the thermal cooling of hot
plasma. These properties are similar to the ones found in other jellyfish
galaxies showing extended X-ray emission. A point-to-point analysis revealed
that this X-ray emission closely follows the ISM distribution, whereas CLOUDY
simulations proved that the ionisation triggered by this warm plasma would be
able to reproduce the [OI]/H$\alpha$ excess observed in JO201. We conclude that
the galactic X-ray emitting plasma is originated on the surface of the ISM as a
result of the ICM-ISM interplay. This process would entail the cooling and
accretion of the ICM onto the galaxy, which could additionally fuel the star
formation, and the emergence of [OI]/H$\alpha$ excess in the optical spectrum.
