SIGMA survey of the Galactic Center region and discovery of a hard X-ray transient.
Abstract
We present the summed image of the Galactic Center region observed by SIGMA/GRANAT from March 1990 to September 1994. It reveals a cluster of ten sources above the 5σ confidence level. Five other sources detected in this region do not appear on the summed image. GRS 1730-312 (= KS 1730-312), whose flaring activity was discovered during the observations performed in September, 1994, is one of them. The flare started on September 22 and lasted approximately 4-days during which the average 35-200keV spectrum can be described by a power law with photon index of 2.5 or by a thermal bremsstrahlung with temperature of 70keV.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- December 1996
- Bibcode:
- 1996A&AS..120C.291V
- Keywords:
-
- STARS: INDIVIDUAL: GRS 1730-312 (GRANAT 1730-312);
- X-RAY: STARS;
- GAMMA RAYS: OBSERVATIONS