Mapping Heating in Clusters of Galaxies
Abstract
Chandra and XMM data on clusters of galaxies have clearly established that the gas in the cores is being heated and redistributed over large scales. This picture is in sharp contrast to the canonical cooling flow model extant prior to Chandra and XMM. Images of cluster cores often show cavities or bubbles associated with energy input from the central AGN. Estimates for the level of energy input from the central radio sources are often sufficient to balance cooling in many clusters. Similarly, XMM RGS data have shown that the integrated spectra for cooling flow clusters lack strong X-ray emission lines from gas at temperatures below 2-3 keV, providing further evidence that the gas is being heated. Using a simple, parameterized differential emission measure model, we have mapped the departures from a canonical, isobaric cooling flow model as a function of position in a sample of clusters. These maps provide constraints on both the location and magnitude of the heating mechanisms at work in the cores of clusters. In several clusters, such as Perseus, we show that there is an excellent spatial correspondence between the sites of heating and the edges of the radio cavities. We discuss the level of heating implied by our maps and compare the implied energy constraints to estimates for various heating mechanisms currently being studied.
- Publication:
-
35th COSPAR Scientific Assembly
- Pub Date:
- 2004
- Bibcode:
- 2004cosp...35.3997W