Evolution of spiral galaxies in the Virgo cluster. I. Statistical analysis of HI deficiency and colors.

The authors present a compilation of H I data and available UBV, far-UV (λ2421 Å) and Hα photometry for 107 spiral and irregular galaxies (S0/a-Im) in the Virgo Cluster, to be compared with a reference sample of 405 "field" galaxies. They confirm with better statistics the H I deficiency of Virgo Cluster spirals, at fixed morphological type and optical surface, which was found in previous studies. The following conclusions are reached: (1) H I deficient spirals are located in subgroups inside Virgo I, in association with the hot gaseous intergalactic medium. Virgo X is not H I deficient. (2) Early-type spirals are more likely to be H I deficient than late-type ones. The deficiency closely correlates with the colors through this type effect. (3) Virgo Cluster spirals have redder (B-V)_T⁰ and (U-B)_T⁰ than reference counterparts, in rough agreement with their H I contents. (4) The Hα+[N II] equivalent widths well correlate with the H I contents for the Virgo Cluster spirals as well as the reference sample.