Neutral hydrogen streams in groups of galaxies. I. Observations.

Groups of nearby, loose galaxies are the object of a search for H I streams, the neutral hydrogen appendages extending outward from the disks of member galaxies. Galaxy parameter tables are presented which summarize observational data gathered with the Arecibo telescope on 15 nearby groups, containing at least one pair of galaxies separated by less than 250 kpc. Of the 15 groups, nine show no evidence of neutral hydrogen appendages, while in the remaining six H I streams associated with at least one member of the aggregate are identified. While previously recognized H I streams have been almost exclusively associated with late-type spiral galaxies, several of those newly identified extend in the regions of early-type galaxies. The 15 nearby groups considered are comprised of 47 galaxies observed in the course of the H I stream search.