EXITE2 Observation of the SIGMA Source GRS 1227+025
Abstract
We report the EXITE2 hard X-ray imaging of the sky around 3C273. A 2h observation on May 8, 1997, shows a 260 mCrab source detected at in each of two bands (50-70 and 70-93 keV) and located 30' from 3C273 and consistent in position with the SIGMA source GRS1227+025. The EXITE2 spectrum is consistent with a power law with photon index 3 and large low energy absorption, as indicated by the GRANAT/SIGMA results. No source was detected in more sensitive followup EXITE2 observations in 2000 and 2001 with 3 upper limits of 190 and 65 mCrab, respectively. Comparison with the flux detected by SIGMA shows the source to be highly variable, suggesting it may be non-thermal and beamed and thus the first example of a ``type 2'' (absorbed) Blazar. Alternatively it might be (an unprecedented) very highly absorbed binary system undergoing accretion disk instability outbursts, possibly either a magnetic CV, or a black hole X-ray nova.
Cite
@article{arxiv.astro-ph/0402133,
title = {EXITE2 Observation of the SIGMA Source GRS 1227+025},
author = {J. E. Grindlay and P. F. Bloser and Y. Chou and T. Narita},
journal= {arXiv preprint arXiv:astro-ph/0402133},
year = {2009}
}
Comments
12 pages, 4 figures, accepted for publication in ApJ