Unveiling the Nature of IGR J17177-3656 with X-Ray, Near-infrared, and Radio Observations

We report on the first broadband (1-200 keV) simultaneous Chandra-INTEGRAL observations of the recently discovered hard X-ray transient IGR J17177-3656 that took place on 2011 March 22, about two weeks after the source discovery. The source had an average absorbed 1-200 keV flux of about 8 × 10^-10 erg cm^-2 s^-1. We extracted a precise X-ray position of IGR J17177-3656, α_J2000 = 17^h17^m42.^s62, δ_J2000 = -36°56'04farcs5 (90% uncertainty of 0farcs6). We also report Swift, near-infrared, and quasi-simultaneous radio follow-up observations. With the multi-wavelength information at hand, we propose IGR J17177-3656 is a low-mass X-ray binary, seen at high inclination, probably hosting a black hole.