AGN heating on cluster atmosphere over cosmic time
Abstract
The AGN energy deposited into the atmosphere of clusters and groups is one of the most important sources providing the energy required to break self-similarity of scaling relations. In simulations, extra energy is often injected into the intracluster medium (ICM) at high redshift, which is the preheating model. At higher redshifts, quasars are expected to contribute most of the energy required in the preheating model, although most the quasar power is lost by radiation. On the other hand, the jet power from continual AGN outbursts, in particular from the central galaxies of clusters, may also distribute energy into the ICM with evidences of X-ray cavities observed using the high resolution and deep Chandra and XMM-Newton data. The AGN jet power can be estimated from the mechanical energy required to inflate the X-ray cavities, and it is found to correlate with the power of the radio lobes filling the cavities. Therefore, we can use the radio power to estimate the AGN jet power in clusters and groups. We apply this method to AGN in a composite cluster samples in redshift 0.1<z<0.6, and calculate the average AGN energy deposited into clusters and groups assuming a simple AGN evolution model. We found that the continual AGN outburst energy could reach more than 1keV per particle for less massive clusters (Lx 5 10^{43} erg/s), which is a significant amount of energy required by preheating model. Thus, we suggest that the continual AGN outbursts should play an important role in the AGN feedback of large-scale structure.
- Publication:
-
Half a Century of X-ray Astronomy
- Pub Date:
- September 2012
- Bibcode:
- 2012hcxa.confE..66M