Hard X-ray sky survey with the SIGMA telescope aboard GRANAT observatory
  During the lifetime of GRANAT orbital observatory the SIGMA telescope collected X-ray images of more than 1/4 of the whole sky. Among these regions the Galactic Center had largest exposure time (~9 million sec). In the present work we review all observations of the SIGMA telescope and present sensitivities achieved with it at different sky regions 
M.G.Revnivtsev (1,2), R.A. Sunyaev (1,2), M.R.Gilfanov (1,2),   E.M.Churazov (1,2), A. Goldwurm (3,4), J.Paul (3,4), P.Mandr...