We report on preliminary results of three Target of Opportunity (TOO) observations of the X-ray transient and black hole candidate XTE J1650-500 performed on 2001 September 11-12, September 21-23, and October 3-4 respectively, with the Narrow Field Instruments (0.1-200 keV) of the BeppoSAX satellite. Inspection of the light curves in different energy bands clearly shows an extreme variability both temporal and spectral. This variability has the consequence that spectra provide acceptable fits only if integrated on a temporal scale of order 104s or even less. However, all spectra are fit by the same model with some parameters that remain unchanged during the 3 TOOs, and others that dramatically change on the above time scale. The model used is a two-phase accretion disk corona model, in which a hot corona with a hybrid electron distribution comptonizes seed photons from a disk. Reflection is important and ionization seems to be very small or even zero. During the first TOO a broad Fe Kαline is clearly seen.
Broadband spectra of XTE J1650-500 with BeppoSAX
MONTANARI, Enrico;FRONTERA, Filippo;
2004
Abstract
We report on preliminary results of three Target of Opportunity (TOO) observations of the X-ray transient and black hole candidate XTE J1650-500 performed on 2001 September 11-12, September 21-23, and October 3-4 respectively, with the Narrow Field Instruments (0.1-200 keV) of the BeppoSAX satellite. Inspection of the light curves in different energy bands clearly shows an extreme variability both temporal and spectral. This variability has the consequence that spectra provide acceptable fits only if integrated on a temporal scale of order 104s or even less. However, all spectra are fit by the same model with some parameters that remain unchanged during the 3 TOOs, and others that dramatically change on the above time scale. The model used is a two-phase accretion disk corona model, in which a hot corona with a hybrid electron distribution comptonizes seed photons from a disk. Reflection is important and ionization seems to be very small or even zero. During the first TOO a broad Fe Kαline is clearly seen.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
