Far-infrared and radio continuum properties of spiral galaxies in clusters

Abstract

Data on the far-infrared (FIR) and radio continuum properties of spiral galaxies in several clusters have been collected from the literature. To assess the effect of the cluster environment on the FIR and radio continuum properties of galaxies, the radial distance from the cluster centre in units of Abell radius is used as a parameter, and the correlations of this with normalized luminosities are looked for. It is found that there is no correlation of FIR luminosity with radial distance. The average value of L_FIR/L_B is also found to be the same for cluster galaxies and isolated galaxies. However, the radio continuum emission shows a significant correlation with radial distance, the radio emission being stronger in the central region. The correlation for galaxies of type Sc and later is stronger than for the earlier types. From a comparison of FIR, Hα and radio continuum correlations, it is concluded that the enhancement of radio emission is due not to changes in star formation in the cluster environment, but to the enhancement of the magnetic field, and possibly also to the increased residence time of electrons in cluster galaxies.