The Heating of Intracluster Gas by the Jet Activities of Active Galactic Nuclei: Is the ``Preheating'' Scenario Realistic?
Abstract
We investigate the nongravitational heating of hot gas in clusters of galaxies (the intracluster medium [ICM]) on the assumption that the gas is heated well before cluster formation (``preheating''). We examine the jet activities of radio galaxies as the sources of excess energy in the ICM, and we examine the deformation of the cosmic microwave background (the Sunyaev-Zeldovich effect) by hot electrons produced at the jet terminal shocks. We show that the observed excess entropy of the ICM and the COBE/FIRAS upper limit for the Compton y-parameter are compatible with each other only when the heating by the jets occurs at relatively small redshifts (z<~3). Since this result contradicts the assumption of preheating, it suggests that the heating occurred simultaneously with or after cluster formation.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2001
- DOI:
- 10.1086/320674
- arXiv:
- arXiv:astro-ph/0105102
- Bibcode:
- 2001ApJ...553L.145Y
- Keywords:
-
- Cosmology: Cosmic Microwave Background;
- Galaxies: Clusters: General;
- Galaxies: Jets;
- Galaxies: Intergalactic Medium;
- X-Rays: Galaxies: Clusters;
- Astrophysics
- E-Print:
- 10 pages including 2 figures, accepted for publication in ApJL