3C28 in Abell 115- A Radio Source With a Twist: Tracing Gas Vortices in a Merging Subcluster Core

Type Conference Paper
Names William R. Forman, Eugene Churazov, Sebastian Heinz, Simona Giacintucci, Christine Jones, Akos Bogdan, Laurence P David, Ralph P. Kraft, Matteo Murgia, Maxim L. Markevitch, Scott W. Randall, Reinout J. Van Weeren, Alexey Vikhlinin
Conference Name American Astronomical Society Meeting Abstracts #224
Volume 224
Date June 1, 2014
Short Title 3C28 in Abell 115- A Radio Source With a Twist
URL http://adsabs.org/2014AAS.22422203F
Library Catalog adslabs.org
Abstract Abell 115 is one of the “bimodal” clusters, first identified from Einstein Observatory X-ray images. The X-ray image is dominated by emission from two subclusters, separated by about 900 kpc, that are in the process of merging. The northern subcluster (A115-N) contains a bright central galaxy that hosts the radio source 3C28. 3C28 has a remarkable morphology. Although there is no evidence of a presently active nucleus, there are two prominent jets connected to a pair of radio lobes, each of which exhibits a radio tail. A115-N shows a classic cold front, the remarkable phenomenon first studied from Chandra cluster observations. We describe the overall structure of the cluster from detailed Chandra obserations. In addition, we exploit the Chandra data and the cold front phenomenon to study the gas motions in and around A115-N that hosts 3C28. The subcluster motion of A115-N through the cluster induces counter-rotating vortices in the subcluster gas that give rise to the unique radio morphology of 3C28 with its two radio tails pointing in the direction of motion of A115-N. Thus, the radio emitting plasma acts as a dye in a fluid tracing the vortices in the X-ray emitting gas, resembling text book pictures of fluid motions.
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