De-excitation C and 0 lines and the 511 keV annihilation line from Sgr A

摘要

We present a model of the observed annihilation emission from the Galactic center. From our estimations it follows that this region should emit also a flux of de-excitation C and 0 lines at the level ≤ 10~(-5) ph cm~(-2) s~(-1). From restrictions based on the observed >100 MeV gamma-ray flux from the Galactic center, ～2 × 10~(-5) ph cm~(-2) s~(-1), we predict that the calculated gamma-ray line flux below 8 MeV is about 2.5 × 10~(-5) ph cm~(-2) s~(-1). A specific line is the one at 1.809 MeV from radioactivity of ~(26)Al. The predicted quasi-stationary flux of the ~(26)Al 1.809 MeV line from the 1° × 1° central region is ≤ 10~(-6) ph cm~2 s~(-1).