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arXiv · 1301.7060

INTEGRAL observations of Sco X-1: evidence for Comptonization up to 200 keV

T. Maiolino·F. D'Amico·J. Braga
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Abstract

We have analyzed a long-term database for Sco X-1 obtained with the telescope IBIS onboard the INTEGRAL satellite in order to study the hard X-ray behavior of Sco X-1 from 20 up to 200 keV. Besides the data used for producing of the INTEGRAL catalog of sources, this is the longest (412 ks) database of IBIS on Sco X-1 up to date. The production of hard X-ray tails in low-mass X-ray binaries is still a matter of debate. Since most of the fits to the high-energy part of the spectra are done with powerlaw models, the physical mechanism for the hard X-ray tail production is unclear. The purpose of this study is to better constrain those possible mechanisms. Our main result shows a strong correlation between the fluxes in the thermal and nonthermal part of Sco X-1 spectra. We thus suggest that Comptonization of lower energy photons is the mechanism for producing hard X-ray tails in Sco X-1.

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T. Maiolino, F. D'Amico, J. Braga. 2013-01-29. INTEGRAL observations of Sco X-1: evidence for Comptonization up to 200 keV. https://doi.org/10.1051/0004-6361/201220677

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