A uniform description of all the astrophysical jets

Abstract

In this talk (at Mondello) I attempt to sketch my understanding of the universal working scheme of all the astrophysical jet sources, or 'bipolar flows', on both stellar and galactic scales, also called 'microquasars', and 'quasars'. A crucial building block will be their medium: extremely relativistic e±-pair plasma performing quasi loss-free E x B-drifts through self-rammed channels, whose guiding equi-partition E- And B-fields convect the electric potential necessary for eventual single-step post-acceleration, at their 'knots' and terminating 'hotspots', or 'heads'. These electromagnetic fields convect half of the jet's power. The indispensible pair plasma is generated in magnetospheric reconnections of the heavy central rotator. Already for this reason, black holes cannot serve as jet engines. During its passage from subsonic to supersonic propagation, still inside its deLaval nozzle, the escaping relativistic pair-plasma passes from a relativistic Maxwellian distribution (almost) to that of a (mono-energetic) Deltafunction, of (uniform) Lorentz-factor γ= 102±2. Clearly, this transition in velocity distribution - in transit through the deLaval nozzle - is not loss-free; it turns the jet engine into a powerful γ-ray emitter, with photon frequencies reaching up to .1026Hz, (corresponding to electron Lorentz factors γ.106), see page 120 of Kundt & Krishna [2004]. So far, all the jets were treated as though propagating in vacuum, as "bare jets". New in this presentation will be an allowance for an embedding medium of non-negligible density, most notably encountered in SS 433 (with its fast-moving X-ray and optical spectral lines), but likewise in our Galactic twin jet. Such an embedding medium, gas or plasma, will try to penetrate into the jet channels, but will instead be expelled, and dragged along by the streaming, extremely relativistic pair plasma, in the form of subrelativistically comoving channel-wall material. In this way, bare jets are converted into (line- And continuum-) emitting "dressed jets".