1205.1691 (Eleonora Torresi)

X-Ray view of Misaligned AGNs    [PDF]

Eleonora Torresi

The Fermi-LAT satellite has recently discovered a small group of radio galaxies and steep spectrum radio sources: the misaligned AGNs (MAGNs) sample. We present the X-ray analysis of all the sources of this sample (7 FRIs and 3 FRIIs) with a firm GeV association. This study supports the idea that FRIIs host more efficient accretion mechanisms (m_dot >0.1) than FRIs (m_dot <0.003). Furthermore, in objects with high accretion rates the Broad Line Regions appear to be very active zones where, in addition to optical lines, the fluorescence iron Kalpha feature at 6.4 keV is also produced. It seems that the FRII jets propagate in an environment very rich in photons, explaining, at least at zeroth order, why the External Compton is the preferred mechanism to produce gamma-rays. In FRIs, where also the iron line is difficult to be detected, the paucity of photons in the circumnuclear ambient seems to favor the Synchrotron Self Compton process.

View original: http://arxiv.org/abs/1205.1691