OSSE Observations of 1E 1740.7=2942 in 1992 September
Abstract
We present data on the galactic X-ray source 1E 1740.7-2942 from the Oriented Scintillation Spectrometer Experiment (OSSE) on board NASA's Compton Gamma Ray Observatory. Episodes of increased low- energy gamma radiation have been reported from this source, including 1-day events in 1990 October and 1992 September. These events, of intensity 7 x 10(exp -3) and 4 x 10(exp -3) photons cm(exp-2) s(exp -1), respectively, have been interpreted as broadened and redishifted position annihilation radiation. OSSE conducted observations of the Gallactic Center region during a 21 day interval from 1992 September 17 thru 1992 October 8. This includes the time of increased 200-450 keV emission from IE 1740.7-2942 reported by SIGMA. The OSSE observations do not confirm this event. For the specific outburst recorded by SIGMA, 1992 Sep. 19.42-20-58 (UT), OSSE data provide an upper limit (3sigma) of 2.4 x 10(exp-3) photons cm(exp-2) s(exp-1).
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 11, 1995
- Accession Number
- ADA464472
Entities
People
- David A. Grabelsky
- G. V. Jung
- J. Eric Grove
- James D. Kurfess
- Mark S. Strickman
- Melville P. Ulmer
- Robert L. Kinzer
- W. Neil Johnson
- William R. Purcell
Organizations
- United States Naval Research Laboratory