Close galaxy pairs in low and medium density regions: The southern sky.

We extend to the southern hemisphere a continuing program of optical and HI observations of galaxy pairs (Chengalur 1993, 1994, 1995 and Nordgren 1997). These pairs are drawn from published redshift catalogs and represent a complete sample. We present new data of 15 pairs observed with the Palomar 5-meter telescope, Mount Stromlo Siding Spring 40-inch telescope, Australia Telescope Compact Array and VLA D synthesis array. These galaxy pairs are all defined as close pairs (projected separations < 100 kpc). HI companions are found near five of 15 pairs.