T. Sbarrato, G. Ghisellini, L. Maraschi, M. Colpi
We study the relation between the mass accretion rate, the jet power, and the
black hole mass of blazars. To this aim, we make use of the Sloan Digital Sky
Survey (SDSS) and the 11 months catalog of blazars detected at energies larger
than 100 MeV by the Large Area Telescope (LAT) onboard the Fermi satellite.
This allows to construct a relatively large sample of blazars with information
about the luminosity (or upper limits) of their emission lines used as a proxy
for the strength of the disc luminosity and on the luminosity of the high
energy emission, used as a proxy for the jet power. We find a good correlation
between the luminosity of the broad lines and the gamma-ray luminosity as
detected by Fermi, both using absolute values of the luminosities and
normalising them to the Eddington value. The data we have analyzed confirm that
the division of blazars into BL Lacs and Flat Spectrum Radio Quasars (FSRQs) is
controlled by the line luminosity in Eddington units. For small values of this
ratio the object is a BL Lac, while it is a FSRQs for large values. The
transition appears smooth, but a much larger number of objects is needed to
confirm this point.
View original:
http://arxiv.org/abs/1108.0927
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