Hubble Space Telescope Images of Stephan's Quintet: Star Cluster Formation in a Compact Group Environment

Abstract

Analysis of Hubble Space Telescope Wide Field Planetary Camera 2 images of Stephan's Quintet, Hickson Compact Group 92, yielded 115 candidate star clusters (with V-I<1.5). Unlike in merger remnants, the cluster candidates in Stephan's Quintet are not clustered in the inner regions of the galaxies; they are spread over the debris and surrounding area. Specifically, these sources are located in the long sweeping tail and spiral arms of NGC 7319, in the tidal debris of NGC 7318B/A, and in the intragroup starburst region north of these galaxies. Analysis of the colors of the clusters indicate several distinct epochs of star formation that appear to trace the complex history of dynamical interactions in this compact group. Based on observations obtained with the NASA/ESA Hubble Space Telescope, which is operated by the Space Telescope Science Institute for the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.