Abell 154 and Virgo : pilot study for H I 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, the cluster Abell 154 has been observed from Arecibo. Fourteen candidate detections were found in two regions of the cluster comprising about 10 percent of the cluster area. These results are compared in detail with those expected for the exhaustively studied Virgo cluster displaced to the distance of A 154. Most of the 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 A 154 profiles are systematically broader than expected 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 A 154 distance, no significant evidence is found for H I deficiency in A 154. 46 refs.