0920021

One of the key investigations so far performed by the INTEGRAL Observatory has been the soft gamma-ray GCDE and the GPS successfully exploited to a depth of better than 1 mCrab in the central region with unprecedented details due to the >20 Ms exposure on SGR A*. The basic outcome is a new view of the gamma-ray domain (E>20 keV) confirmed by the discovery to date of about 1000 sources belonging to all the galactic and extragalactic classes. More recently the new INTEGRAL view of the extragalactic soft gamma-ray sky has been complemented by the excellent sky coverage provided by the SWIFT/BAT extragalactic survey. INTEGRAL has still a factor of 10 better sensitivity over the Galaxy plane due to the 6Ms average exposure. This is true for the whole plane except for two important regions that are only covered at a level of ~2.2 Ms and ~1.9 Ms by the end of AO8: the outer Perseus spiral arms. In those regions the material is considerably less dense and we will be able to extend our present studies of compact objects through a detailed comparison of the relative populations of all classes of gamma-ray emitting galactic types in the very different environment provided in these outer regions. Finally last but not least this is a unique opportunity to obtain a deep soft gamma ray coverage of the Galaxy plane: an invaluable INTEGRAL Legacy for future high energy studies. This proposal is specifically designed to reach this goal thus making a corner stone in the high energy understanding of our Galaxy behaviour in the 17-600 keV range and provide a text book for future population studies. This is a strategic goal in view of the lack of any high energy mission planned in the next decade and it has been identified as a long term legacy in the INTEGRAL extension science case 2010. To achieve this goal we propose to observe the still two weakly exposed regions at galactic latitude b=0 and longitude of l=150 and 225 degr [truncated! Please see actual data for full text]