Jets from Black Holes in Quasars
Alan Marscher (Boston University)
Although black holes consume most of the matter that falls toward them, a small fraction
gets heated and shot out along the rotational poles in the form of jets having flow
velocities very close to the speed of light. The most powerful jets are found in quasars,
which are the most luminous type of active galactic nucleus (AGN), where the mass of the
central black hole is millions or even billions of times more massive than the Sun. I will
describe recent observations at radio, visible, X-ray, and gamma-ray frequencies that probe
the jets closer to the black hole than has been possible previously. The data are consistent
with the hypothesis that jets are propelled by magnetic fields that are wound up by ionized
gas orbiting the black hole just outside the event horizon.
