The environments of FRII radio sources
Abstract
Using ROSAT observations, we estimate gas pressures in the X-ray-emitting medium surrounding 63 FRII radio galaxies and quasars. We compare these pressures with the internal pressures of the radio-emitting plasma estimated by assuming minimum energy or equipartition. In the majority of cases (including 12/13 sources with modelled, spatially resolved X-ray emission) radio sources appear to be underpressured with respect to the external medium, suggesting that simple minimum-energy arguments underestimate the internal energy density of the sources. We discuss possible departures from the minimum-energy condition and the consequences of our result for models of the dynamics of radio galaxies, in particular self-similar models.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 2000
- DOI:
- 10.1046/j.1365-8711.2000.03883.x
- arXiv:
- arXiv:astro-ph/0007260
- Bibcode:
- 2000MNRAS.319..562H
- Keywords:
-
- GALAXIES: ACTIVE;
- GALAXIES: CLUSTERS: GENERAL;
- X-RAYS: GALAXIES;
- Astrophysics
- E-Print:
- 11 pages, 4 figures, accepted for MNRAS