3–200 keV Spectral States and Variability of theINTEGRALBlack Hole Binary IGR J17464−3213

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 bea HEAO-1 transient, H1743-322. In this paper we report on the high energybehaviour of this BHC studied with the three main instruments onboard INTEGRAL.The data, collected with unprecedented sensitivity in the hard X-Ray range,show a quite hard Comptonised emission from 3 keV up to 150 keV during therising part of the source outburst, with no thermal emission detectable. A fewdays later, a prominent soft disk multicolour component appears, with the hardtail luminosity almost unchanged: 10-9 erg*cm-2*s-1. Two months later, during asecond monitoring campaign near the end of the outburst, the observed diskcomponent was unchanged. Conversely, the Comptonised emission from thecentral-hot part of the disk reduced by a factor of 10. We present here itslong term behaviour in different energy ranges and the combined JEM-X, SPI andIBIS wide band spectral evolution of this source.Comment: 12 pages, 4 figures, accepted for pubblication in AP