Relativistic Jets

[Oscar Wilde]

I was recently watching a program when "gas" jets, or more properly, plasma jets became a topic. In regards to black holes, I am interested in how such jets can form. I believe that it has something to do with the magnetic fields around a BH, but I am unsure as to how
plasma jets form, and where the matter comes from. How can matter, which has presumably passed the event horizon, be shot out in such a jet?

All feedback appreciated,



Oscar

[SpiffyKavu]

I don't know much on this matter, but I was under the impression that the material never reached the event horizon. The accretion disk contains ionized gas, and can be in very turbulent flows. The disk can create large scale magnetic fields, which are collimated along the rotational axis by the rotation of the disk.

Some of the gas in the disk travels along this magnetic field. The accretion disk is not a solid object; it has a maximum density in the mid-plane, and falls off approximately exponentially off the plane. It is this outlying gas that makes its way along the magnetic field to form a beam of particles: a jet.

But don't take my word for it. You can read up on magnetohydrodynamics, or talk to professors about it.