The broad-band spectrum of Cyg X-2 with INTEGRAL
- Autori: LAVAGETTO G; DI SALVO T; FALANGA M; IARIA R; ROBBA N R; BURDERI L; LEWIN W H G; MENDEZ M; STELLA L; VAN DER KLIS M
- Anno di pubblicazione: 2006
- Tipologia: Articolo in rivista (Articolo in rivista)
- OA Link: http://hdl.handle.net/10447/7254
Abstract
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.