Compact groups ( CGs ) of galaxies — relatively poor groups of galaxies in which the typical separations between members is of the order of a galaxy diameter — offer an exceptional laboratory for the study of dense galaxian environments with short ( < 1 Gyr ) dynamical time-scales .

In this paper , we present an objectively defined catalog of CGs in 153 sq deg of the Sloan Digital Sky Survey Early Data Release ( SDSS EDR ) .
To identify CGs , we applied a modified version of Hickson ’ s ( ) criteria aimed at finding the highest density CGs and thus reducing the number of chance alignments .
Our catalog contains 175 CGs down to a limiting galaxy magnitude of r ^ { * } = 21 .
The resulting catalog has a median depth of z _ { med } \approx 0.13 , substantially deeper than previous CG catalogs .
Since the SDSS will eventually image up to one quarter of the celestial sphere , we expect our final catalog , based upon the completed SDSS , will contain on the order of 5,000 – 10,000 CGs .
This catalog will be useful for conducting studies of the general characteristics of CGs , their environments , and their component galaxies .