EDP Sciences
Free access
Issue
A&A
Volume 394, Number 1, October IV 2002
Page(s) L9 - L13
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20021282


A&A 394, L9-L13 (2002)
DOI: 10.1051/0004-6361:20021282

Letter

Ion-dominated plasma and the origin of jets in quasars

A. Hujeirat1, M. Camenzind2 and M. Livio3

1  Max-Planck-Institut für Astronomie, 69117 Heidelberg, Germany
2  Landessternwarte-Koenigstuhl, 69117 Heidelberg, Germany
3  Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA

(Received 22 July 2002 / Accepted 3 September 2002)

Abstract
Low cooling plasmas associated with large kinetic energies are likely to be the origin of the kpc-extended and well collimated extra-galactic jets.

It is proposed that jets are launched from a layer, governed by a highly diffusive, super-Keplerian rotating and thermally dominated by virial-hot and magnetized ion-plasma. The launching layer is located between the accretion disk and the corona surrounding the nucleus. The matter in the layer is causally connected to both the disk and to the central engine. Moreover we find that coronae, in the absence of heating from below, are dynamically unstable to thermal ion-conduction, and that accretion disks become intrinsically advection-dominated.

We confirm the capability of this multi-layer model to form jets by carrying out 3D axisymmetric quasi-stationary MHD calculations with high spatial resolution, and taking into account turbulent and magnetic diffusion. The new multi-layer topology accommodates several previously proposed elements for jet-initiation, in particular the ion-torus, the magneto-centrifugal and the truncated disk - advective tori models.


Key words: galaxies: jets, accretion disks -- black holes, methods: numerical, plasma, MHD

Offprint request: A. Hujeirat, hujeirat@mpia-hd.mpg.de




© ESO 2002