Blazars in hard X-rays
  Although blazars are thought to emit most of their luminosity in the
gamma-ray band, there are subclasses of them very prominent in hard X-rays.
These are the best candidates to be studied by Simbol-X. They are at the
extremes of the blazar sequence, having very small or very high jet powers. The
former are the class of TeV emitting BL Lacs, whose synchrotron emission often
peaks at tens of keV or more. The latter are the blazars with the most powerful
jets and have high black hole masses accreting at high (i.e. close to
Eddington) rates. These sources are predicted to have their high energy peak
even below the MeV band, and therefore are very promising candidates to be
studied with Simbol-X.
