Origin and Collimation of Compact Source Jets and Acceleration Mechanisms

Abstract

Supersonic outflows and jets are associated with various types of astrophysical objects such as young stellar objects (YSOs e.g., HH 30, HH 34), active galactic nuclei (AGNs e.g., M87), high mass X-ray binaries (HMXB e.g., SS433, Cyg X-3), black hole transients (or microquasars; e.g., GRS 1915+105, GRO 1655-40), low mass X-ray binaries (LMXB e.g., Cir X-1). The physics to explain these outflows and jets is expected to be the same though the scales differ. The first observational evidence of highly collimated jets was the twin lobes of the radio source Cygnus A (Jennison and Das Gupta, 1953). Also apparently associated to jet phenomena are the gamma ray bursts (GRBs). The mechanisms associated with origin, collimation and acceleration of these outflows are still shrouded in mystery. Besides, the production of these outflows is often associated with the acceleration of relativistic particles. Our study aims to address these issues by means of theoretical and numerical investigation of the physical processes occurring in the accretion disk and corona that surrounds the central source and which allow for the jet/outflow formation. These include the possible origin of outflows and jets caused by energy and mass loss across the shock transition during accretion flow towards the compact object. The effects of magnetic fields and the rotating accretion disk are also believed to be significant for initial launching of jets and far away from the sources too and these will be investigated in the framework of the model above. Besides, we intend to explore the role of first order Fermi particle acceleration by magnetic reconnection around these objects.