Dust deficiency in Virgo spirals

The results of an analysis of far-infrared (FIR) and 21-cm data for a sample of 102 spiral galaxies in the Virgo cluster are presented. We show that H I deficient galaxies have lower 60- and 100-μm fluxes and cooler far-infrared colour temperatures than those with normal H I content. We interpret these results in the context of a two-component model for the far-infrared emission: a warm component associated with star formation and H II regions, and a cool 'cirrus-like' component of dust heated by the interstellar radiation field. We find that, for a typical spiral in the core of the cluster, at least half of the diffuse dust has been stripped and the star formation activity suppressed by a factor of 3, compared to normal field galaxies. The dust stripping confirms the presence of a diffuse dust component in Virgo spirals and the validity of current models for the FIR emission in spiral galaxies. (author)