HEAO 3 Observations of the Galactic Center 511 keV Line
Abstract
The existence of an intense narrow electron/position annihilation line from the direction of the Galactic center is unquestioned; however, the source of the positrons remains a mystery. It is believed the line emisssion has two components: one compact at or near the Galactic center, and the other extended in the equatorial plane of the Galaxy. A compact component is suggested by several reports of intensity variations, including one from our group based on HEAO 3 data. Since the original HEAO 3 analysis, our algorithms have been greatly improved and we have gained a much better understanding of systematic effects which could influence the results. Given the importance of the result and the significantly improved analysis techniques now avaiable, the data have been reanalyzed. For a single point source at the Galactic center, the revised line intensities are (1.25 +/- 0.18) x 10-3 photons cm-2 s-1 for the fall of 1979 and (0.99 +/- 0.18) x 103 photons cm-2 x-1 for the spring of 1980.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- June 1994
- DOI:
- 10.1086/191983
- Bibcode:
- 1994ApJS...92..387M
- Keywords:
-
- Galactic Nuclei;
- Galactic Radiation;
- Gamma Ray Astronomy;
- Line Spectra;
- Positron Annihilation;
- Flux Density;
- Heao 3;
- Milky Way Galaxy;
- Astronomy;
- GAMMA RAYS: OBSERVATIONS;
- GALAXY: CENTER