SIGMA-SURVEY OF THE GALACTIC-CENTER REGION AND DISCOVERY OF A HARD X-RAY TRANSIENT

Authors
VARGAS M GOLDWURM A DENIS M PAUL J BORREL V ROQUES JP JOURDAIN E NIEL M TRUDOLYUBOV S CHURAZOV E GILFANOV M SUNYAEV R DYACHKOV A KHAVENSON N CHULKOV I BOGOMOLOV A
Citation
M. Vargas et al., SIGMA-SURVEY OF THE GALACTIC-CENTER REGION AND DISCOVERY OF A HARD X-RAY TRANSIENT, Astronomy & Astrophysics. Supplement series, 120(4), 1996, pp. 291-294
Citations number
22
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Astronomy & Astrophysics. Supplement series → ACNP
ISSN journal
03650138
Volume
120
Issue
4
Year of publication
1996
Pages
291 - 294
Database
ISI
SICI code
0365-0138(1996)120:4<291:SOTGRA>2.0.ZU;2-O
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 o f ten sources above the 5 sigma confidence level. Five other sources d etected in this region do not appear on the summed image. GRS 1730-312 (= KS 1730-312), whose flaring activity was discovered during the obs ervations performed in September, 1994, is one of them. The hare start ed on September 22 and lasted approximately 4 days during which the av erage 35-200 keV spectrum can be described by a power law with photon index of 2.5 or by a thermal bremsstrahlung with temperature of 70 keV .