A PERSISTENT HARD X-RAY SOURCE OBSERVED IN THE TERZAN-1 GLOBULAR-CLUSTER BY THE SIGMA-TELESCOPE

Authors
BORRELL V BOUCHET L JOURDAIN E ROQUES JP VARGAS M GOLDWURM A DENIS M PAUL J CHURAZOV E GILFANOV M FINOGUENOV A SUNYAEV R DYACHKOV A KHAVENSON N CHULKOV I NOVIKOV B
Citation
V. Borrell et al., A PERSISTENT HARD X-RAY SOURCE OBSERVED IN THE TERZAN-1 GLOBULAR-CLUSTER BY THE SIGMA-TELESCOPE, Astronomy & Astrophysics. Supplement series, 120(4), 1996, pp. 249-250
Citations number
13
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Astronomy & Astrophysics. Supplement series → ACNP
ISSN journal
03650138
Volume
120
Issue
4
Year of publication
1996
Pages
249 - 250
Database
ISI
SICI code
0365-0138(1996)120:4<249:APHXSO>2.0.ZU;2-1
Abstract
A persistent hard X-ray emission has been observed by the SIGMA telesc ope in the Terzan 1 globular cluster. The photon spectrum is reproduce d by a power law with spectral index equal to -3.2 +/- 0.7. The lumino sity calculated in the 40-75 keV energy range assuming a distance of 1 0 kpc is equal to (4 +/- 0.8) 10(35) erg s(-1). This source is already known as an X-ray burster and has been studied by HEAO1, SL2-XRT, Exo sat, Rosat and ART-P and it may be a LMXB with a neutron star as the c ompact member.