| The Chandra High Resolution Camera observed the fields of five hard X-ray sources in order to help us obtain X-ray coordinates with sub-arcsecond precision. These observations provide the most accurate X-ray positions known for IGR J16393−4643 and for IGR J17091−3624. The obscured X-ray pulsar IGR J16393−4643 lies at R.A.(J2000)= 16h 39m 05.47s, and Dec.= −46deg 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 2MASS star. The black hole candidate IGR J17091−3624 was observed during its 2011 outburst providing coordinates of R.A.= 17h 09m 07.59s, and Dec.= −36deg 24\' 25.4\". This position is compatible with those of the proposed optical/IR and radio counterparts, solidifying the source’s status as a micro- quasar. Three targets, IGR J14043−6148, IGR J16358−4726, and IGR J17597−2201, were not detected. We obtained 3σ upper limits of, respectively, 1.7, 1.8, and 1.5 × 10−12 erg cm−2 s−1 on their 2–10 keV fluxes. |
