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 similar to 1 keV, an electron temperature of similar to 3 keV and an optical depth tau similar to 8. Assuming spherical geometry, the radius of the seed-photons emitting region is similar to 17 km. The source shows no hard X-ray emission; it was detected only at a 3 sigma 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.
|Numero di pagine||4|
|Rivista||ASTRONOMY & ASTROPHYSICS|
|Stato di pubblicazione||Published - 2006|
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