AAS 199th meeting, Washington, DC, January 2002
Session 69. Clusters of Galaxies - I
Oral, Tuesday, January 8, 2002, 10:00-11:30am, Jefferson West

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[69.05] Thermal and Nonthermal Effects in Galaxy Cluster Mergers

J. C. Kempner (University of Virginia)

I present several observational studies, at radio and X--ray wavelengths, of merging clusters of galaxies. The first is a search for radio halos and relics among Abell clusters in the Westerbork Northern Sky Survey at 327~MHz. Eighteen candidate sources were found, including 7 previously unknown ones. All 11 previously known sources within the sample which were above the survey's surface brightness limit were redetected. I have begun follow up observations of two of the new sources, A1240 and A2034, using the VLA. Preliminary results from the observations of A2034 show additional signatures of a merger, including a large number of tailed radio galaxies. These galaxies' locations within the cluster are correlated with the proposed location of a merger shock detected by ROSAT. I also explore the X--ray/radio correlations in Abell~2034 using Cycle 2 Chandra observations. These data also show a sharp feature which may be a shock at the position of the candidate radio relic.

Using Chandra ACIS-I observations I explore the dynamics of the merger in Abell~85 as well as the correlations with the cluster's radio relic. I develop a dynamical model for the south subcluster merger and discuss the geometrical properties of the system, both using an analysis of the cold front. The cold front in the south subcluster also shows evidence of hydrodynamic instability. The subcluster itself shows significant signs of interaction with the main cluster, including a disturbed morphology indicative of ram pressure effects, and heating of the subcluster gas. Furthermore, I discuss the correlation between the X--ray morphology of the subcluster and the structure of the large radio source associated with it. The radio relic associated with the southwest cluster is also discussed in the context of detecting Inverse Compton radiation in X--rays from scattering off the Cosmic Microwave Background.

The author(s) of this abstract have provided an email address for comments about the abstract: jkempner@virginia.edu

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