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A Chandra View of the Multiple Merger In Abell 2744

Joshua C. Kempner·Laurence P. David
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Abstract

We present a Chandra observation of the merging cluster of galaxies Abell 2744. The cluster shows strong evidence for an ongoing major merger which we believe to be responsible for the radio halo. X-ray emission and temperature maps of the cluster, combined with the spatial and redshift distribution of the galaxies, indicate a roughly north-south axis for the merger, with a significant velocity component along the line of sight. The merger is occurring at a very large velocity, with M = 2-3. In addition, there is a small merging subcluster toward the northwest, unrelated to the major merger, which shows evidence of a bow shock. A hydrodynamical analysis of the subcluster indicates a merger velocity corresponding to a Mach number of ~1.2, consistent with a simple infall model. This infalling subcluster may also be re-exciting electrons in the radio halo. Its small Mach number lends support to turbulent reacceleration models for radio halo formation.

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Joshua C. Kempner, Laurence P. David. 2003-10-07. A Chandra View of the Multiple Merger In Abell 2744. https://doi.org/10.1111/j.1365-2966.2004.07534.x

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