The structure of the radio halo
VLA imaging of the most extended structure in M 87 at 20 and 90 cm reveals a complex structure extending to about 40 kpc in radius. The images suggest a complicated, turbulent, transonic flow beginning at the boundary with the inner lobes and ending at the boundary of the bubble-like structure which is seen on the largest scales of the radio emission. The scale is interestingly similar to the “cooling core” of the X-ray source.
Models of the jet argue for kinetic luminosities of ∼ 1044 ergs s−1. Most of this energy must ultimately be dissipated in heat. The morphology of the outer lobes suggests that this is occurring on the scale of the cooling core. This input energy rate exceeds the current luminosity of the cooling core in X-rays (∼ 1043 ergs s−1). Thus this suggests that the jet is providing the energy to power to the M 87 cooling core and that currently the excess energy is being absorbed in the expansion of the region rather than a contraction as envisioned in “cooling flow” theory.
KeywordsRadio Emission Radio Source Radio Galaxy Cool Flow Transonic Flow
Unable to display preview. Download preview PDF.
- Baum, S. A. (1992): in Clusters and Superclusters of Galaxies, ed A. C. Fabian, Kluwer, Dordrect, p 171.Google Scholar
- Bicknell, G. V. (1999): these proceedingsGoogle Scholar
- Binney, J.: these proceedingsGoogle Scholar
- Eilek, J. A., Owen, F. N. & Zhou, F. (1999): this meetingGoogle Scholar
- Fabricant, D. & Gorenstein, P. (1983): ApJ, bf 267, 535Google Scholar
- Jaffe, W. (1992): in Clusters and Superclusters of Galaxies, ed A. C. Fabian, Kluwer, Dordrect, p 109.Google Scholar
- Keel, W. C., Owen, F. N. & Eilek, J. A. (1996): in P. E. Hardee, A. H. Bridle & J. A. Zensus, eds, Energy Transport in Radio Galaxies and Quasars (San Francisco: ASP), 209–214Google Scholar