AAS 199th meeting, Washington, DC, January 2002
Session 150. Particular AGNs and Seyferts
Oral, Thursday, January 10, 2002, 2:00-3:30pm, International Ballroom West

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[150.04] A Chandra Study of the Cavity around Cygnus~A

D. A. Smith, A. S. Wilson (University of Maryland)

We present an analysis of a Chandra ACIS-S observation of the radio galaxy Cygnus A. The large-scale extended X-ray emission is dominated by the thermal intracluster gas, and we have derived the radial dependence of temperature, density and abundance by a deprojection analysis. In the central 2 arc min (~q 180 kpc), the dominant feature is a limb-brightened, elliptical (presumably prolate-spheroidal in three dimensions) structure, the major axis of which coincides with that of the radio source. This structure appears to be the observational manifestation of the cavity which is expected to be inflated in the intracluster medium by relativistic material which has passed through the hot spots at the ends of the jets (Scheuer 1974). Using our model of the cluster gas, we have subtracted the foreground and background X-ray emission from that observed in the direction of the cavity and thus derived upper limits to X-ray emission from any diffusely spread thermal gas within the cavity. Consequences for the dynamical state of the cavity will be discussed.

This research made use of funding through NASA grant NAG-81027.

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

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