Outskirts of Galaxy Clusters

LMXB populations in galaxy outskirts: globular clusters and supernova kicks

For the first time, we have systematically explored the population of discrete X-ray sources in the outskirts of early-type galaxies. Based on a broad sample of 20 galaxies observed with Chandra we detected overdensity of X-ray sources in their outskirts. The overdensity appears as halos of resolved sources around the galaxies. These halos are broader than the stellar light, extending out to at...

The Structure and Content of Galaxy Outskirts

The outer regions of galaxies are expected to contain important clues about the way in which galaxies are assembled. Although quantitative study of these parts has been severely limited in the past, breakthroughs are now being made thanks to the combination of wide-area star counts, deep HST imagery and 8-m class spectroscopy. I review here several recent results concerning substructure, star c...

Warm gas in the outskirts of galaxy clusters – The cluster soft excess phenomenon

The cluster soft excess emission indicates the presence of large amounts of warm gas (T∼ 10 K) in the neighborhood of galaxy clusters. Among the clusters that display this phenomenon is the Coma cluster, the nearest rich galaxy cluster. The excess emission is more prominent at the cluster’s outskirts than at its center. Detailed studies of its large-scale emission – up to ∼2.6 Mpc from the clus...

Galaxy Clusters

Galaxy Activity in Merging Binary Galaxy Clusters

We present the results of a study of galaxy activity in two merging binary clusters (A168 and A1750) using the Sloan Digital Sky Survey (SDSS) data supplemented with the data in the literature. We have investigated the merger histories of A168 and A1750 by combining the results from a two-body dynamical model and X-ray data. In A168 two subclusters appear to have passed each other and to be com...