Complete Local-Volume Groups Survey IAU 2012 poster

Galaxy groups contain >50% of the galaxies in the local Universe, and are a critical environment for galaxy evolution, the development of the hot, X-ray emitting intergalactic medium, and of cosmic structure in general. However, we currently lack any statistically complete, representative sample of groups which could be used to study these issues. To remedy this problem, we began the Complete Local-Volume Groups Survey (CLoGS), whose aim is to examine a complete, 53-member sample of groups within 80 Mpc, observed in the X-ray, radio and optical regimes. GMRT radio observations of the sample are near completion, and X-ray observations of a 26-group high-richness subsample (itself statistically complete) will be finished by early 2013. In this poster we describe the goals and selection criteria of the sample, give examples of the types of groups being detected by our observations, and show results from an in-depth analysis of one system (NGC 4261). (To be presented at Cosmic Evolution of Groups and Clusters, a special session of the IAU XXVIII General Assembly, August 20-31 2012, Beijing, China) Further details of the CLoGS project can be found at http://www.sr.bham.ac.uk/~ejos/CLoGS.html