3-200 keV Spectral States and Variability of the INTEGRAL Black Hole Binary IGR J17464-3213
Capitanio, F.; Bird, A. J.; Ubertini, P.; Bazzano, A.; Cadolle Bel, M.; Dean, A. J.; Natalucci, L.; Kretschmar, P.; De Cesare, G.; Del Santo, M.; Joinet, A.; Jourdain, E.; Zdziarski, A. A.; Goldwurm, A.; Barlow, E. J.
Italy, Germany, Switzerland, Poland, France, United Kingdom
Abstract
On March 2003, IBIS, the gamma-ray imager on board the INTEGRAL satellite, detected an outburst from a new source, IGR J17464-3213, that turned out to be a HEAO 1 transient, H1743-322. In this paper we report on the high-energy behavior of this black hole candidate (BHC) studied with the three main instruments on board INTEGRAL. The data, collected with unprecedented sensitivity in the hard X-ray range, show a quite hard Comptonized emission from 3 up to 150 keV during the rising part of the source outburst, with no thermal emission detectable. A few days later, a prominent soft-disk multicolor component appears, with the hard tail luminosity almost unchanged: ~5×10-9 ergs cm-2 s-1. Two months later, during a second monitoring campaign near the end of the outburst, the observed disk component was unchanged. Conversely, the Comptonized emission from the central hot part of the disk reduced by a factor of ~10. We present here its long-term behavior in different energy ranges and the combined JEM-X, SPI, and IBIS wideband spectral evolution of this source.
Based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic, and Poland and with the participation of Russia and the USA.