Numerical simulations of the extragalactic jet in M87

Abstract

Observations of the jet in M87 and its surroundings are used to constrain hydrodynamical calculations of this object. These constraints include atmospheric profiles of the gas surrounding M87, the observed point of recollimation at Knot A, the observed half-opening angle of the jet (~ 3&#176 before deprojection), the inferred inclination of the jet with respect to the plane of the sky (~ 42 &#176), etc. Many jets are simulated in a systematic search for the parameters which reproduce the opening angle and recollimation point of the M87 jet. From those, estimates are made of the density and pressure of the M87 jet, and of such quantities as mass flux, and power output. During this search it was also found that the simulated jets did not obey the Mach angle relationship, and that recollimation of a jet depends primarily on the ram pressure of a jet as opposed to the thermal pressure.