SIGMA observations of X-ray Nova Velorum 1993 (GRS 1009-45)
Abstract
We report on hard X-ray observations of X-ray Nova Velorum 1993 (GRS 1009-45) performed with the SIGMA coded mask X-ray telescope in January 1994. The source was clearly detected with a flux of about 60 mCrab in the 40-150 keV energy band during the two observations with a hard spectrum (alpha ~ - 1.9) extending up to ~ 150 keV. These observations confirm the duration of the activity of the source in hard X-rays over 100 days after the first maximum and suggest a spectral hardening which has already been observed in Nova Muscae. These and other characteristics found in these observations strengthen the case for this Nova to be a black hole candidate similar to Nova Muscae.
Cite
@article{arxiv.astro-ph/9709089,
title = {SIGMA observations of X-ray Nova Velorum 1993 (GRS 1009-45)},
author = {P. Goldoni and M. Vargas and A. Goldwurm and P. Laurent and J. -P. Roques and E. Jourdain and J. Malzac and G. Vedrenne and M. Revnivtsev and E. Churazov and M. Gilfanov and R. Sunyaev and A. Dyachkov and N. Khavenson and I. Tserenin and N. Kuleshova},
journal= {arXiv preprint arXiv:astro-ph/9709089},
year = {2007}
}
Comments
4 pages LaTeX, 2 postscript figures, Accepted by Astronomy and AstroPhysics