Marina Kaufman Bernado

Max Planck Institute for Radio Astronomy

torek, 20. 5. 2008, ob 15h v F6

Magnetic fields play a key role in the formation of jets. Very high magnetic fields at the surface of neutron stars or in the accretion disk of black holes inhibit the production of jets. We have quantified the upper limit value of the magnetic field strength that allow the jet formation in X-ray binaries and AGNs. By using the Alfven Radius, , we have studied what we called the basic condition for jet formation, or (LSO, last stable orbit). The basic condition has a direct dependency with the magnetic field strength and the mass accretion rate. We have analysed these results in 3-D and 2-D plots in the case of neutron star and black hole accretor systems, respectively. For this purpose, we did a systematic search of all available observational data for magnetic field strength and mass accretion rate. We studied all the possible compact object accreting scenarios and discern when the formation is possible and under which magnetic field conditions: classical X-ray pulsars, low-mass X-ray binaries with neutron stars (Z- and Atoll-sources), millisecond X-ray pulsars, black-hole X-ray binaries, and AGNs. The theoretical results that we obtain are in complete agreement with available observational data.