is a particle jet the same as a black hole jet or what is a jet ?

Answer 1

Objects as diverse as X-ray binaries, radio galaxies, quasars, and even our Galactic center, are powered by the gravitational energy released when surrounding gas is sucked into the black hole sitting in their cores, a process astronomers call accretion. Apart from copious radiation, one of the manifestations of this accretion energy release is the production of so-called jets, collimated beams of matter that are expelled from the innermost regions of accretion disks. These jets shine particularly brightly at radio frequencies. The complicated physics of jet acceleration and collimation close to a black hole is still a mystery. Yet, the observed similarity (in morphology and spectrum) of jets from black holes of different mass suggests that they share a common physical origin. Scientists from the Max-Planck-Institut for Astrophysics have followed this lead and investigated the consequences of considering all astrophysical black holes to be members of one single class. They formulated a scale invariance hypothesis, which states (when translated into words) that a black hole of a billion solar masses in the nucleus of a galaxy, surrounded by a large accretion disk and launching a huge jet into the intergalactic space, can be scaled down by a factor of a billion and look exactly like a black hole of one solar mass, with its small accretion disk and jet, like the ones we observe in binary systems in our own Galaxy.

Answer 2

Hi. It's hard to be certain what the jets consist of, but they move at relativistic speed. http://science.nasa.gov/headlines/y2007/18dec_assault.htm?list189652 shows a new image of a jet hitting another galaxy. Not some place I would want to be right now!