Title: Imaging our sister galaxy M31 in hard X rays
Proposal ID: 0120199
Subject category: Extragalactic Object
Principal investigator: Trinchieri
Institute:
Abstract
We propose to observe the nearby galaxy M31 with INTEGRAL to obtain the first imaging information in the
hard X rays of an external galaxy similar to the Milky Way. Hard X-ray emission has recently been detected
with BeppoSAX up to 35 keV, but the lack of imaging capability of the PDS instrument prevented its
localization. INTEGRAL will allow us to assess whether the hard X-ray flux can be attributed to a few
sources (or even to a single one) or it is the result of the superposition of a large number of sources in
the bulge of M31. It will be possible to study the high-energy spectrum up to 150 keV and to compare the
properties of the hard X-ray sources of M31 and those of our Galaxy.