Head tail high velocity clouds: a possibility to test the theory of dark matter subhaloes

Full text: Assuming an extragalactic origin for the ensemble of Compact High Velocity Clouds (CHVCs) and an amount of dark matter arising from cosmological lambda-CDM theory, the CHVCs should be embedded in dark matter subhaloes when entering the galactic gravitational potential. The baryonic matter interact with the hot halo gas and face ram pressure stripping as well as a deceleration relative to the motion of its own dark matter potential, which is not affected by drag force. Based on a stable self-gravitating gas sphere in both hydrodynamic and thermal equilibrium (several heating and cooling processes are considered) surrounded by a hot ambient medium, this work shows how different additional gravitational potentials influence the effect of ram pressure stripping. This setup models the infall of observed CHVCs with a head-tail structure, using hydrodynamic FLASH Code 2.5. (author)