Neutral Hydrogen in Virgo Cluster Galaxies

Twenty-one centimetre wavelength measurements with the Mark I and Mark II radio telescopes have been made of the neutral hydrogen content of 25 galaxies in the Virgo cluster. Spectra of some of the brighter galaxies are shown in Fig. 1; the neutral hydrogen parameters of each galaxy are given in Table I. A comparison of the neutral hydrogen mass-to-luminosity radio $$M_\text H/L$$ and the neutral hydrogen surface density $$\sigma_\text H$$ for the Virgo cluster galaxies with field galaxies indicates that on average the cluster galaxies are deficient in neutral hydrogen by a factor of ∼0.63. Calculations of galactic collision times suggest that collisions are likely to be responsible for the deficiency of gas in the Virgo cluster galaxies at the present epoch.