Study on the effect of galactic atmospheres on shock induced disruption of extragalactic jets

This dissertation studies the interaction of collimated outflows of gas, or beams, from the nuclei of elliptical galaxies with the gas medium surrounding these galaxies. In particular, the distribution of the gas medium around galaxies at rest with respect to this gas medium is explored. In this case, the density and temperature of the gas varies spatially and their relationship will be determined by the energy balance of the gas in the gravitational potential defined by the galaxy. One finds that the gas environment or atmosphere around a galaxy can be described either as an outflowing wind, in the case where heating dominates, or a cooling inflow, in the case where cooling dominates. The responses of a beam propagating through a cooling inflow atmosphere is found to be very different from the response of a beam in a wind atmosphere. In the case of a cooling inflow, the beam can make a transition from a regime where the beam is dominated by biconical shocks into a regime where the beam is dominated by planar shocks. The planar shocks cause a laminar, supersonic beam to disrupt, becoming subsonic and turbulent. The observed manifestations of this change in the beam is believed to be responsible for the radio morphology associated with galaxies at the centers of cooling inflows