The Impact and Fate of the ISM in Compact Groups of Galaxies
Abstract
Compact groups of galaxies provide a unique environment to study the evolution of the ISM and mechanisms by which star formation occurs amid continuous gravitational encounters. We present Spitzer, 2MASS, and HI observations of a sample of 12 Hickson Compact Groups (HCGs) and a total of 45 galaxy members. The galaxies in this sample have observed infrared characteristics that are distinctly different from the sample of field galaxies in the Spitzer FLS or SINGS. Most notably, HCG galaxies exhibit a "gap" in infrared color space, separating gas-rich groups from gas-poor groups, that is sparsely populated and which is not seen in either the FLS or SINGS. This gap may suggest a rapid evolution of galaxy properties in response to dynamical effects in HCGs. Moreover, there are striking trends seen between the ratio of HI mass to dynamical mass for an entire group and the infrared colors of the individual member galaxies. These trends suggest that the constituent galaxies in compact groups are related to the type of group in which they reside. The results of this project can provide insight for the earlier universe when environments similar to those found in compact groups of galaxies were common.
- Publication:
-
The Evolving ISM in the Milky Way and Nearby Galaxies
- Pub Date:
- January 2009
- Bibcode:
- 2009eimw.confE..10J
- Keywords:
-
- galaxies: ISM;
- infrared: galaxies;
- infrared