Title: INTEGRAL observation of the sky region around the quasar 4C 71.07


Proposal ID: 0120041
Subject category: Extragalactic Object
Principal investigator: Malizia
Institute: TESRE-CNR

Abstract

We propose an INTEGRAL observation of the quasar 4C71.07 and its surrounding sky region. This is a high redshift quasar at z=2.172 very powerful in hard X-rays and so easily detectable by JEMX, IBIS and SPI. It has also a V magnitude of 16.5 and so will be easily observed by OMC. Recent BATSE and OSSE data are consistent with the object being a low frequency peaked or red blazar: having the synchrotron and Compton peaks probably localized in the mm-FIR and MeV band respectively. In fact the high energy data (OSSE/BATSE versus EGRET) suggest the presence of a broad hump in the 10E20-10E22 Hz band but both the theoretical models (Synchrotron Self Compton or/and External Compton ) used to explain the energy mechanism at work in the Blazar objects, do not fit the data completely well. With INTEGRAL observation proposed here, we will have the opportunity to invistigare the MeV region of the spectrum where the Compton peak falls and therefore definitely disentangle the two theoritical models involved. Forthermore we propose to point the observation not centered on 4C71.07 but a few arcmin away from it. Following this strategy also the two galaxies M81 and M82 will fall in the IBIS fully coded field of view. Also the observation of these two galaxies will be very important since they are very close to each other and their hard X-ray emission is contaminated. Thanks to IBIS angular resolution (12') we will be able to resolve the two sources and estimate their high energy emission. We request to perform two repeated observations of 100 Ks each at interval of 6-7 months, appropriate to catch 4C71.07 (our primary target) at different spectral states to study its variability. Each observation of 100 Ks will be enough for IBIS to detect 4C71.07 at 12 sigma in 20-200 keV and a few sigma at energies greater than 200 keV. Also M81 and M82 will be easily detectable in each 100 Ks exposure. Note that the total time reported in PGT is 3 times (i.e. 3 sources) the requested time.