Gas dynamic stripping and X-ray emission of cluster elliptical galaxies

Detailed three-dimensional numerical simulations of an elliptical galaxy or biting in a gas-rich cluster of galaxies indicate that gas dynamic strippin g is less efficient than the results from previous, simpler calculations by Takeda et al. and Gaetz et al. implied. This result is consistent with X-r ay data for cluster elliptical galaxies. Hydrodynamic torques and direct ac cretion of orbital angular momentum can result in the formation of a cold g aseous disc, even in a non-rotating galaxy. The gas lost by cluster galaxie s via the process of gas dynamic stripping tends to produce a colder, chemi cally enriched cluster gas core. A comparison of the models with the availa ble X-ray data of cluster galaxies shows that the X-ray luminosity distribu tion of cluster galaxies may reflect hydrodynamic stripping, but also that a purely hydrodynamic treatment is inadequate for the cooler interstellar m edium near the centre of the galaxy.