In this paper we report on the broadband X-ray properties of a complete sample of 33 absorbed Seyfert galaxies hard X-ray selected with integral. The high quality broadband spectra obtained with both xmm, and integral-IBIS data are well reproduced wi
th an absorbed primary emission with a high energy cutoff and its scattered fraction below 2-3 keV, plus the Compton reflection features. A high energy cut-off is found in 30% of the sample, with an average value below 150 keV. The diagnostic plot NH vs Fobs(2-10 keV)/F(20-100 keV) allowed the isolation of the Compton thick objects, and may represent a useful tool for future hard X-ray observations of newly discovered AGN. We are unable to associate the reflection components with the absorbing gas as a torus, a more complex scenario being necessary. In the Compton thin sources, a fraction (but not all) of the Fe K line needs to be produced in a gas possibly associated with the optical Broad Line Region, responsible also for the absorption. We still need a Compton thick medium (not intercepting the line of sight) likely associated to a torus, which contributes to the Fe line intensity and produces the observed reflection continuum above 10 keV. The so-called Iwasawa-Taniguchi effect can not be confirmed with our data. Finally, the comparison with a sample of unobscured AGN shows that, type 1 and type 2 (once corrected for absorption) Seyfert are characterized by the same nuclear/accretion properties (luminosity, bolometric luminosity, Eddington ratio), supporting the unified view.
PSR J1833-1034 and its associated Pulsar Wind Nebula (PWN) has been investigated in depth through X-ray observations ranging from 0.1 to 200 keV. The low energy X-ray data from Chandra reveal a complex morphology that is characterised by a bright cen
tral plerion, no thermal shell and an extended diffuse halo. The spectral emission from the central plerion softens with radial distance from the pulsar, with the spectral index ranging from $Gamma $ = 1.61 in the central region to $Gamma $ =2.36 at the edge of the PWN. At higher energy INTEGRAL detected the source in the 17--200 keV range. The data analysis clearly shows that the main contribution to the spectral emission in the hard X-ray energy range is originated from the PWN, while the pulsar is dominant above 200 keV. Recent HESS observations in the high energy gamma-ray domain show that PSR J1833-1034 is a bright TeV emitter, with a flux corresponding to $sim$2 per cent of the Crab in 1--10 TeV range. In addition the spectral shape in the TeV energy region matches well with that in the hard X-rays observed by INTEGRAL. Based on these findings, we conclude that the emission from the pulsar and its associated PWN can be described in a scenario where hard X-rays are produced through synchrotron light of electrons with Lorentz factor $gammasim10^{9}$ in a magnetic field of $sim$10 micro Gauss. In this hypothesis the TeV emission is due to Inverse Compton interaction of the cooled electrons off the Cosmic Microwave Background photons. Search for PSR J1833-1034 X-ray pulsed emission, via RXTE and Swift X-ray observations, resulted in an upper limit that is about 50 per cent.
After almost 5 years of operation, ESAs International Gamma-Ray Astrophysics Laboratory (INTEGRAL) Space Observatory has unveiled a new soft Gamma ray sky and produced a remarkable harvest of results, ranging from identification of new high energy so
urces, to the discovery of dozens of variable sources to the mapping of the Aluminum emission from the Galaxy Plane to the presence of electrons and positrons generating the annihilation line in the Galaxy central radian. INTEGRAL is continuing the deep observations of the Galactic Plane and of the whole sky in the soft Gamma ray range. The new IBIS gamma ray catalogue contains more than 420 sources detected above 20 keV. We present a view of the INTEGRAL high energy sky with particular regard to sources emitting at high energy, including Active Galactic Nuclei (AGN), HESS/MAGIC counterparts and new view of the cosmic gamma ray diffuse background.
