Chocked accretion onto a Schwarzschild black hole: A hydrodynamical jet-launching mechanism

Emilio Tejeda (UMNSH)

RESUMEN: Astrophysical jets are ubiquitously found in the Universe, from young stellar objects to active galactic nuclei, and accompany high-energy phenomena such as gamma ray bursts, micro-quasars and compact object mergers. There are, however, several important open issues about them that we still do not fully understand, e.g. the process of launching the jet in the first place, as well as the connection between the accreted and ejected flows. In this talk, I will present a novel ejection mechanism in which, by breaking spherical symmetry, a radially accreting flow transitions into an inflow-outflow configuration that can naturally account for the inner engine behind a jet-launching system. This mechanism unveils a flux-limited accretion regime in which, for a sufficiently large accretion rate, the incoming material chokes at a gravitational bottleneck and the excess flux is redirected by a density gradient as a bipolar outflow. I describe the choked accretion mechanism first in terms of an exact relativistic model based on the assumption of an ultrarelativistic stiff fluid. Then I present the results of numerical simulations where this assumption is relaxed and show that this mechanism can operate under more general conditions. Finally, I discuss the applicability of this model as a jet-launching mechanism in different astrophysical settings.