  Ram pressure stripping of satellite galaxies is thought to be a ubiquitous
process in galaxy clusters, and a growing number of observations reveal
satellites at different stages of stripping. However, in order to determine the
fate of any individual galaxy, we turn to predictions from either simulations
or analytic models. It is not well-determined whether simulations and analytic
models agree in their predictions, nor the causes of disagreement. Here we
investigate ram pressure stripping in the reference EAGLE hydrodynamical
cosmological simulation, and compare the results to predictions from analytic
models. We track the evolution of galaxies with stellar mass $M_{*} > 10^{9} \,
\mathrm{M_{\odot}}$ and initial bound gas mass $M_{\mathrm{gas}} > 10^{9} \,
\mathrm{M_{\odot}}$ that fall into galaxy clusters ($M_{\mathrm{200c}} >
10^{14} \, \mathrm{M_{\odot}}$) between $z = 0.27$ and $z = 0$. We divide each
galaxy into its neutral gas disk and hot ionized gas halo and compare the
evolution of the stripped gas fraction in the simulation to that predicted by
analytic formulations for the two gas phases, as well as to a toy model that
computes the motions of gas particles under the combined effects of gravity and
a spatially uniform ram pressure. We find that the analytic models generally
underpredict the stripping rate of neutral gas and overpredict that of ionized
gas, with significant scatter between the model and simulation stripping
timescales. This is due to opposing physical effects: the enhancement of ram
pressure stripping by stellar feedback, and the suppression of stripping by the
compaction of galactic gas.
