view Abstract Citations (13) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS SIGMA Observations of the Galactic Center at 511 keV Malet, I. ; Roques, J. P. ; Bouchet, L. ; Vedrenne, G. ; Paul, J. ; Cordier, B. ; Ballet, J. ; Lebrun, F. ; Sunyaev, R. ; Churazov, E. ; Gilfanov, M. ; Khavenson, N. ; Dyachkov, A. ; Kuleshova, N. ; Sheikhet, A. ; Tzerenin, I. Abstract The SIGMA experiment on board the Granat satellite has carried out numerous observations of the Galactic center region during the past four years, totalling more than 1200 hr of data. After a careful study of an correction for the systematic errors, we derive a 2 sigma upper limit of 2.3 x 10-4 gamma/sq cm s for the narrow 511 keV emission from 1E 1740.7-2942, suggested as the most likely candidate for the variable 511 keV line emission. No compact narrow 511 keV radiation source has been detected within a radius of approximately 2 deg around this object. Publication: The Astrophysical Journal Pub Date: May 1995 DOI: 10.1086/175597 Bibcode: 1995ApJ...444..222M Keywords: Galactic Nuclei; Gamma Ray Astronomy; Milky Way Galaxy; X Ray Astronomy; Emission Spectra; Energy Spectra; Galactic Radiation; Radiation Sources; Astronomy; GALAXY: CENTER; GAMMA RAYS: OBSERVATIONS; LINE: IDENTIFICATION full text sources ADS | data products SIMBAD (2)