Jet Launching Structure Resolved Near the Supermassive Black Hole in M87
  Approximately 10% of active galactic nuclei exhibit relativistic jets, which
are powered by accretion of matter onto super massive black holes. While the
measured width profiles of such jets on large scales agree with theories of
magnetic collimation, predicted structure on accretion disk scales at the jet
launch point has not been detected. We report radio interferometry observations
at 1.3mm wavelength of the elliptical galaxy M87 that spatially resolve the
base of the jet in this source. The derived size of 5.5 +/- 0.4 Schwarzschild
radii is significantly smaller than the innermost edge of a retrograde
accretion disk, suggesting that the M87 jet is powered by an accretion disk in
a prograde orbit around a spinning black hole.
