Powering AGNs with super-critical black holes
  We propose a novel mechanism for powering the central engines of Active
Galactic Nuclei through super-critical (type II) black hole collapse. In this
picture, ~$10^3 M_\odot$ of material collapsing at relativistic speeds can
trigger a gravitational shock, which can eject a large percentage of the
collapsing matter at relativistic speeds, leaving behind a "light" black hole.
In the presence of a poloidal magnetic field, the plasma collimates along two
jets, and the associated electron synchrotron radiation can easily account for
the observed radio luminosities, sizes and durations of AGN jets. For Lorentz
factors of order 100 and magnetic fields of a few hundred $\mu G$, synchrotron
electrons can shine for $10^6$ yrs, producing jets of sizes of order 100 kpc.
This mechanism may also be relevant for Gamma Ray Bursts and, in the absence of
magnetic field, supernova explosions.
