5 research outputs found
An X-ray view of the INTEGRAL/IBIS blazars
Aim of this work is a broad-band study with INTEGRAL, Swift and XMM-Newton
satellites of a sample of 9 blazars (7 FSRQ and 2 BL Lac) with redshift up to
about 4. The spectral analysis has shown clear evidence of a flattening of the
continuum towards the low energies ( keV observer frame). This behaviour
is well reproduced both with an absorbed power-law model
(- cm in the rest-frame of the sources) or a
broken power-law continuum model (with an energy break below 3 keV in the
observer-frame). No Compton reflection features, Fe line and hump at
high energies, have been detected, with the exception of the source IGR
J22517+2218 that shows the presence of a weak iron line. In this work we also
investigate a possible correlation between the absorption column density
and the red-shift. We confirm the existence of a -z trend, with the higher
absorption at z2 for a larger sample compared to previous results. The
distribution of the and the photon index is also presented. The
hard X-ray data allow us to detect highly absorbed sources (with
cm in rest-frame of the source) characterized by photon
index distribution peaked at harder values () with respect to
that obtained with XMM data only ().Comment: accepted for publication in MNRA