Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters

Details Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters

2012-03-30

arxiv.org/abs/1204.0006v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

Accepted for publication in New Journal of Physics Focus Issue on Clusters of Galaxies

Scientific paper

The radiative cooling timescales at the centers of hot atmospheres surrounding elliptical galaxies, groups, and clusters are much shorter than their ages. Therefore, hot atmospheres are expected to cool and to form stars. Cold gas and star formation are observed in central cluster galaxies but at levels below those expected from an unimpeded cooling flow. X-ray observations have shown that wholesale cooling is being offset by mechanical heating from radio active galactic nuclei. Feedback is widely considered to be an important and perhaps unavoidable consequence of the evolution of galaxies and supermassive black holes. We show that cooling X-ray atmospheres and the ensuing star formation and nuclear activity are probably coupled to a self-regulated feedback loop. While the energetics are now reasonably well understood, other aspects of feedback are not. We highlight the problems of atmospheric heating and transport processes, accretion, and nuclear activity, and we discuss the potential role of black hole spin. We discuss X-ray imagery showing that the chemical elements produced by central galaxies are being dispersed on large scales by outflows launched from the vicinity of supermassive black holes. Finally, we comment on the growing evidence for mechanical heating of distant cluster atmospheres by radio jets and its potential consequences for the excess entropy in hot halos and a possible decline in the number of distant cooling flows.

Affiliated with

Also associated with

No associations

Rating

Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-654675