6533b82afe1ef96bd128c335
RESEARCH PRODUCT
The broad-band spectrum of Cyg X-2 with INTEGRAL
Luigi StellaR. IariaT. Di SalvoMariano MendezMaurizio FalangaLuciano BurderiN. R. RobbaWalter H. G. LewinM. Van Der KlisG. Lavagettosubject
Physicsstars : individual : Cygnus X-2Astrophysics::High Energy Astrophysical PhenomenaAstrophysics (astro-ph)Spectrum (functional analysis)FOS: Physical sciencesBroad bandAstronomy and AstrophysicsRadiusAstrophysicsAstrophysicsaccretion accretion diskstars : neutronSpherical geometrySpace and Planetary Sciencebinaries : closeOptical depth (astrophysics)Electron temperatureclose; stars : individual : Cygnus X-2; stars : neutron [accretion accretion disks; binaries]description
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 tau ~ 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 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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2005-10-12 |