A MAXIMUM-ENTROPY MAP OF THE 511 KEV POSITRON-ANNIHILATION LINE EMISSION DISTRIBUTION NEAR THE GALACTIC-CENTER

We have applied the maximum entropy method to a large data set based o n Compton Gamma Ray Observatory (CGRO)/OSSE, Solar Maximum Mission, Tr ansient Gamma-Ray Spectrometer, Gamma-Ray Imaging Spectrometer, HEXAGO NE, and FIGARO observational results of the Galactic center 511 keV ra diation in order to produce a map of the 511 keV line emission. This m ap suggests two components: a central bulge with a flux of 5.7 +/- 0.2 9 x 10(-4) photons cm(-2)s(-1) and a Galactic plane (GP) component wit h a flux of 2.2 +/- 0.4 x 10(-4) photons cm(-2) s(-1). The central bul ge is located at l = -0.degrees 47 +/- 0.degrees 24, b = 0.degrees 1 /- 0.degrees 18, and FWHM = 5.degrees 28 +/- 0.degrees 48. We note tha t the position of the GP component coincides with a strong hot spot in the COMPTEL map of 1.8 MeV Al-26 line emission. A comparison between CGRO/OSSE and other instruments with larger field of view suggests an extended diffuse 511 keV emission. An interesting hot spot at l = -4 d egrees, b = 7 degrees with a flux of similar to 2 x 10(-4)photons cm(- 2)s(-1) is shown on our map. A bootstrap test indicates that the signi ficance level of this feature is 3.5 sigma.