INTEGRAL/IBIS search for e-e+ annihilation radiation from the Galactic Center Region

Abstract

Electron-positron annihilation radiation from the Galactic Center region has been detected since the seventies, but its astrophysical origin is still a topic of a scientific debate. We have analyzed data of the gamma-ray imager IBIS/ISGRI onboard of ESA's INTEGRAL platform in the e${}^{-}$e${}^{+}$ line. During the first year of the missions Galactic Center Deep Exposure no evidence for point sources at 511 keV has been found in the ISGRI data; the $2\sigma$ upper limit for resolved single point sources is estimated to be $1.6\times 10^{-4}phc{m}^{-2}{s}^{-1}$.

6 pages, 3 figures; Cospar 2004. To be published in: Advances in Space Research