A&A 394, L9-L13 (2002)
Ion-dominated plasma and the origin of jets in quasars A. Hujeirat1, M. Camenzind2 and M. Livio3
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)
Low cooling plasmas associated with large kinetic
energies are likely to be the origin of the kpc-extended and well collimated
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.
galaxies: jets, accretion disks --
black holes, methods: numerical, plasma, MHD
Offprint request: A. Hujeirat, email@example.com
© ESO 2002