The research will be a continuation of studies of the Virgo Cluster of galaxies, its local supercluster, and related galaxy systems. The proposed work is largely observational, using the Arecibo telescope to observe the 21 centimeter spectral line of neutral hydrogen (HI) to study the gas content and internal dynamics of dwarf galaxies in Virgo, in low density regions behind Virgo and toward the supercluster pole, and around groups of galaxies within the local supercluster. The global HI properties of these galaxies will allow a critical comparison of these observations with N-body simulations which should resolve questions concerning mass segregation, recent theories of biased galaxy formation, and various mechanisms of morphological segregation and HI deficiencies. The new HI data, along with data from other sources, will extend the Tully-Fisher correlation between the blue color magnitude (luminosity) and HI profile width of the spectral line to the quite small dwarf galaxies which constitute the dominant population of most galaxy groups. Undergraduate students will be directly involved in the research.
