CHANDRA OBSERVATIONS OF FIVE INTEGRAL SOURCES: NEW X-RAY POSITIONS FOR IGR J16393-4643 AND IGR J17091-3624

The Chandra High Resolution Camera observed the fields of five hard X-ray sources in order to help us obtain X-ray coordinates with subarcsecond precision. These observations provide the most accurate X-ray positions known for IGR J16393-4643 and IGR J17091-3624. The obscured X-ray pulsar IGR J16393-4643 lies at R. A. (J2000) = 16(h)39(m)05(s).47, and decl. = -46 degrees 42'13 ''.0 (error radius of 0 ''.6 at 90% confidence). This position is incompatible with the previously proposed counterpart 2MASS J16390535-4642137, and it points instead to a new counterpart candidate that is possibly blended with the Two Micron All Sky Survey star. The black hole candidate IGR J17091-3624 was observed during its 2011 outburst providing coordinates of R.A. = 17(h)09(m)07(s).59, and decl. = -36 degrees 24'25 ''.4. This position is compatible with those of the proposed optical/IR and radio counterparts, solidifying the source's status as a microquasar. Three targets, IGR J14043-6148, IGR J16358-4726, and IGR J17597-2201, were not detected. We obtained 3 sigma upper limits of, respectively, 1.7, 1.8, and 1.5 x 10(-12) erg cm(-2) s(-1) on their 2-10 keV fluxes.