Mid-Infrared Evidence for Accelerated Evolution in Compact Group Galaxies

Authors :: Walker, Lisa May
Johnson, Kelsey E.
Gallagher, Sarah C.
Hibbard, John E.
Hornschemeier, Ann E.
Charlton, Jane C.
Jarrett, Thomas H.
Source :: ASPC 423 (2010) 88
Publication Year :: 2009
Abstract: We find evidence for accelerated evolution in compact group galaxies from the distribution in mid-infrared colorspace of 42 galaxies from 12 Hickson Compact Groups (HCGs) compared to the the distributions of several other samples including the LVL+SINGS galaxies, interacting galaxies, and galaxies from the Coma Cluster. We find that the HCG galaxies are not uniformly distributed in colorspace, as well as quantitative evidence for a gap. Galaxies in the infall region of the Coma cluster also exhibit a non-uniform distribution and a less well defined gap, which may reflect a similarity with the compact group environment. Neither the Coma Center or interacting samples show evidence of a gap, leading us to speculate that the gap is unique to the environment of high galaxy density where gas has not been fully processed or stripped.<br />Comment: To appear in the Proceedings of the Galaxy Wars: Stellar Populations and Star Formation in Interacting Galaxies Conference