MAGNETIC RECONNECTION AND PARTICLE-ACCELERATION IN ACTIVE GALACTIC NUCLEI

Magnetic field-aligned electric fields an characteristic features of m agnetic reconnection processes operating in externally agitated magnet ized plasmas. An especially interesting environment for such a process are the coronae of accretion disks in active galactic nuclei (AGN). T here, Keplerian shear flows perturb the quite strong disk magnetic fie ld leading to intense current sheets. It was previously shown that giv en field strengths of 200 G in a shear flow, reconnection driven magne tic field aligned electric fields can accelerate electrons up to Loren tz factors of about 2000 in those objects thus providing us with a pos sible solution of the injection (pre-acceleration) problem. However, w hereas in the framework of magnetohydrodynamics the formation of the f ield-aligned electric fields can be described consistently, the questi on has to be addressed whether the charged particles can really be acc elerated up to the maximum energy supplied by the field-aligned electr ic potentials, since the accelerated particles undergo energy losses e ither by synchrotron or inverse Compton mechanisms. We present relativ istic particle simulations starting from electric and magnetic fields obtained from magnetohydrodynamic simulations of magnetic reconnection in an idealized AGN configuration including nonthermal radiative loss es. The numerical results prove that the relativistic electrons can be effectively accelerated even in the presence of an intense radiation bath. Energies from 50MeV up to 40GeV can be reached easily, depending on the energy density of the photon bath. The strong acceleration of the electrons mainly along the magnetic field lines leads to a very an isotropic velocity distribution in phase space. Not even an extremely high photon energy density is able to completely smooth the anisotropi c pitch angle distribution which is characteristic for quasi monoenerg etic particle beams.