Detection of Gamma-Ray Emission from the Eta-Carinae Region

We present the results of extensive observations by the gamma-ray AGILE satellite of the Galactic region hosting the Carina nebula and the remarkable colliding wind binary Eta Carinae ( Delta *h Car) during the period 2007 July-2009 January. We detect a gamma-ray source (1AGL J1043-5931) consistent with the position of Delta *h Car. If 1AGL J1043-5931 is associated with the Car system, our data provide the long sought first detection above 100 MeV of a colliding wind binary. The average gamma-ray flux above 100 MeV and integrated over the preperiastron period 2007 July-2008 October is F Delta *g = (37 +/- 5) X 10-8 ph cm-2 s-1 corresponding to an average gamma-ray luminosity of L Delta *g = 3.4 X 1034 erg s-1 for a distance of 2.3 kpc. We also report a two-day gamma-ray flaring episode of 1AGL J1043-5931 on 2008 October 11-13 possibly related to a transient acceleration and radiation episode of the strongly variable shock in the system.