The tail of the stripped gas that cooled: H I, hα, and X-ray observational signatures of ram pressure stripping.
TONNESEN S. and BRYAN G.L.
Abstract (from CDS):
Galaxies moving through the intracluster medium (ICM) of a cluster of galaxies can lose gas via ram pressure stripping. This stripped gas forms a tail behind the galaxy which is potentially observable. In this paper, we carry out hydrodynamical simulations of a galaxy undergoing stripping with a focus on the gas properties in the wake and their observational signatures. We include radiative cooling in an adaptive hydrocode in order to investigate the impact of a clumpy, multi-phase interstellar medium. We find that including cooling results in a very different morphology for the gas in the tail, with a much wider range of temperatures and densities. The tail is significantly narrower in runs with radiative cooling, in agreement with observed wakes. In addition, we make detailed predictions of H I, Hα, and X-ray emission for the wake, showing that we generally expect detectable H I and Hα signatures, but no observable X-ray emission (at least for our chosen ram pressure strength and ICM conditions). We find that the relative strength of the Hα diagnostic depends somewhat on our adopted minimum temperature floor (below which we set cooling to zero to mimic physics processes not included in the simulation).