Ion-dominated plasma and the origin of jets in quasars

Abstract

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.

Launching proton-dominated jets from accreting Kerr Black Holes: the case of M87

“…(4), the time scale for the PMF to diffuse throughout the corona is much longer than the time scale characterizing the dynamics of the plasma in the TZ. Noting that in the the absence of heating from below, rotational-unsupported corona around BHs are thermally unstable (Hujeirat et al, 2002), and that thermal conduction across the PMF lines is much weaker than along the field lines, we conclude that BH-corona most likely are relatively cold voids and therefore are thermally and dynamically unimportant for both the jet and the disk.…”

“…A similar approach has been presented by Hujeirat et al (2002Hujeirat et al ( , 2003; Hujeirat (2003Hujeirat ( , 2004, though it applies for the Newtonian regime only. The present work is concerned with the extension of the above-mentioned Newtonian model into the general relativistic regime.…”

“…Numerical calculations of Hujeirat et al (2002) have shown that a fraction of roughlyṀ w /Ṁ d ≈ 1/20 of the inflowing matter goes into the form of a wind.…”

“…In order to construct a reasonable profile for the angular velocity, we follow the results of the theoretical and numerical investigation of Hujeirat et al (2002Hujeirat et al ( , 2003. Accordingly, the strong poloidal magnetic fields in the boundary layer, i.e.…”

Black Holes, the Big Bang and the Habitable Universe: Are They Really Compatible?

“…Indeed, this appears to agree with the theoretical considerations and numerical MHD calculations of accretion flows onto UCOs. However,the dynamics of the plasma at the vicinity of the surface of a NS or an event horizon is strongly affected by the strong gravitational field and therefore must be more difficult for particles to escape the system to subsequently form powerful jets [13] [14] [15]. Moreover, in the absence of a solid surface, the speed of inward-oriented accretion flows is expected to increase, rather than decrease, as they approach the event-horizon.…”