H-1 IMAGING OF NGC-3312 AND NGC-3314A - A FOREGROUND GROUP TO THE HYDRA CLUSTER

We present a VLA neutral hydrogen image pointed toward the center of the Hydra I (Abell 1060) Galaxy Cluster, but which is offset in velocity from the cluster mean. The velocity range covers NGC 3312, NGC 3314a, and a small ring galaxy. In contrast to an H I image of the spirals that are projected close to the center of Virgo, these three galaxies are gas rich, have extended H I disks, and show signs of tidal interactions. A comparison of the Einstein IPC data for Virgo and Hydra suggests that the ICM density in Hydra is an order of magnitude higher than at the location of the shrunken H I disks in Virgo. Although galaxies with high relative velocities with respect to the cluster mean are expected to be close to the cluster center, the absence of any effects of the dense ICM on the H I distribution can most easily be understood if the three galaxies form a separate group, which is close to the center of Hydra in projection only. This supports an earlier suggestion made by Fitchett & Merritt [ApJ, 335, 18 (1988) which was based on a dynamical analysis of the cluster.