Detection and analysis of a new INTEGRAL hard X-ray transient, IGR J17285-2922

We present the transient nature of INTEGRAL source IGR J17285–2922, identified from a single period of activity during an IBIS/ISGRI Galactic Centre Deep Exposure in September 2003. The source has a maximum detection significance of 14σ in the 20–100 keV energy range and exhibits a flux of 6.5 mCrab before it moves out of the ISGRI field of view. The source is visible to at least 150 keV and its spectrum can be fit with a power law slope of $\Gamma=2.1 \pm0.17$; a more physical model could not be fit due to poor statistics. Detected characteristics are consistent with the source being a Galactic low-mass X-ray binary harbouring a black hole or neutron star