ABELL-154 AND VIRGO - PILOT-STUDY FOR HI OBSERVATIONS OF DISTANT CLUSTERS OF GALAXIES

As a test of procedures required to study the H I contents of spiral galaxies in distant clusters of galaxies, we have observed the cluster Abell 154 from Arecibo. 2 Fourteen candidate detections were found in two regions of the cluster comprising about 10% of the cluster area. We compare these results in detail with those we would expect to obtain for the exhaustively studied Virgo cluster displaced to the distance of A154. Most of our candidate detections are likely to be the combined profiles of two or more spiral galaxies, many of them too faint to appear on the list of morphological types classified by Dressler (1980). Any attempt to identify these H I signals with known bright spirals is problematic at best. The A154 profiles are systematically broader than we would expect for Virgo, but a crude application of the Tully-Fisher correlation indicates that they are still consistent with available photometric data. While the H I deficiency in Virgo would still be apparent at the A154 distance, we find no significant evidence for H I deficiency in A154.