The broad-band spectrum of Cyg X-2 with INTEGRAL
نویسندگان
چکیده
We study the broad band (3-100 keV) spectrum of Cygnus X–2 with INTEGRAL. We find that the spectrum is well fitted by a Comptonized component with a seed-photons temperature of ∼ 1 keV, an electron temperature of ∼ 3 keV and an optical depth τ ∼ 8. Assuming spherical geometry, the radius of the seed-photons emitting region is ∼ 17 km. The source shows no hard X-ray emission; it was detected only at a 3σ level above 40 keV. We also analyzed public ISGRI data of Cyg X–2 to investigate the presence of a hard X–ray component. We report the possible presence of hard X-ray emission in one data set.
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