Collisional removal of H I from the inner disks of virgo cluster galaxies

Abstract

There is sufficient observational evidence to show that many Virgo Cluster spirals are H I deficient in their inner disks (in addition to being H I deficient globally, as previously established). It is shown here that collisions between galaxies in a cluster can lead to the removal of H I gas from these galaxies while leaving the H₂ gas, undisturbed. This follows directly from the application of the Spitzer-Baade collisional gas removal mechanism to galaxies consisting of stars and a two-component ISM consisting of H I and H², with H I having the largest filling factor. This can account for both the observed H I deficiency in the inner regions and the normal H₂ content of these galaxies. The frequency of galaxy collisions in the Virgo Cluster is shown to be large enough to make collisional gas removal a viable mechanism.