High Energy Phenomena in Eta Carinae

Journal of astrophysics and astronomy

Sonja Rebecchi¹  Corinne Rossi⁴  Roberto F. Viotti1²  Lucio Angelo Antonelli³ 

[1]ASI Science Data Centre, ESA-ESRIN, 00044 Frascati, Italy.$$

[2]Istituto di Astrofisica Spaziale, CNR, 00133 Roma, Italy.$$

[3]Osservatorio Astronomico di Roma, 00040 Monte Porzio, Italy.$$

[4]Dipartimento di Fisica, Università La Sapienza, 00185 Roma, Italy.$$

关键词: Colliding winds model;    non-thermal emission;    stars: 𝜂 Car;    X-ray emission.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

We have investigated with BeppoSAX the long term behaviour of the harder X-ray component of the supposed supermassive binary system 𝜂 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 keV emission 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 𝜂 Car is instead well fitted with an absorbed powerlaw spectrum with photon index 2.53, suggesting non-thermal emission as an alternative model for the core source.

【 授权许可】

Unknown