High Energy Phenomena in Eta Carinae
Author(s)
Viotti, R. F.
Antonelli, L. A.
Rebecchi, S.
Date Issued
2002-06-01
Mission(s)
Abstract
We have investigated with BeppoSAX the long term behaviour of the harder X-ray component of the supposed supermassive binary system Car along its 5.52 year cycle. We have found that in March 1998 during egress from the last December 1997 eclipse, this component was the same as outside eclipse, but for a large (3.5) increase of NHh, that can be attributed to the presence or formation of opaque matter in front of the source near periastron. Unexpectedly, at that time the iron 6.7 keVemission line was 40% stronger. BeppoSAX has for the first time found a hard X-ray tail extending to at least 50 keV, that cannot be adequately fitted with an additional hotter thermal component. The 2-100 keV spectrum of Car is instead well fitted with an absorbed powerlaw spectrum with photon index