Blowing Bubbles in the Intracluster Medium: The Growth and Evolution of Radio Lobes from Active Galactic Nuclei
Abstract
Observations from Chandra have allowed detailed analyses of cavities created by radio lobes in the X-ray emission of galaxy clusters. These lobes are thought to heat galaxy clusters and provide a solution to the cooling flow problem, but their impacts integrated over time are not known. We provide a simple model for the evolution of a radio lobe in a cluster atmosphere. The motion of a lobe is determined by its pressure and the pressure and density of the surrounding atmosphere. The model assumes the lobe is made up of three components: electrons, a magnetic field, and non-radiating particles. These three components evolve due to inputs from the jet, changing external pressure, and radiative losses. The synchrotron spectrum of the lobe is computed from the electron distribution and magnetic field strength. We chose to model the sources 2A 0335+096, A2052, A2199, A478, and A4059 with data from Birzan et al. (2008). Our simple model is able to match observed radio fluxes at frequencies 327, 1400, 4500, and 8500 MHz. Although the simple model works well, the number of free parameters and the lack of data limits how well we can constrain the properties of these systems. Using lower frequency radio data and a more complete physical model will enable better measurements of the impacts of distant radio galaxies on their cluster hosts in the future. This work is supported in part by the NSF REU and DOD ASSURE programs under NSF grant no. 0754568 and by the Smithsonian Institution.
- Publication:
-
American Astronomical Society Meeting Abstracts #221
- Pub Date:
- January 2013
- Bibcode:
- 2013AAS...22133954T