Chandra Observations of NGC 4636 - An Elliptical Galaxy in Turmoil

Abstract

Chandra images show symmetric, 8 kpc long, arm-like features in the X-ray halo surrounding NGC 4636. The leading edges of these features are sharp and are accompanied by temperature increases of ~30%. These properties, along with their scale and symmetry, suggest that the arm-like structures are produced by nuclear outburst driven shocks. We interpret these observations as part of a cycle in which cooling gas originally fueled a nuclear outburst about 3 X 10^{6} years ago leading to shocks that reheat the cooling gas, thus preventing the accumulation of significant amounts of cooled gas in the galaxy center and temporarily starving the central AGN.