Chandra HRC Localization of the Low-Mass X-Ray Binaries X1624–490 and X1702–429: The Infrared Counterparts

We report on the precise localization of the low-mass X-ray binaries X1624-490 and X1702-429 with the Chandra HRC-I. We determine the best positions to be 16h28m02.ˢ825, - 49°11′54.″61 and 17h06m15.ˢ314, - 43°02′08.″69 (J2000.0) for X1624-490 and X1702-429, respectively, with the nominal Chandra positional uncertainty of 0.″6. We also obtained deep IR observations of the fields of these sources in an effort to identify the IR counterparts. A single, faint (Ks = 18.3 ± 0.1) source is visible inside the Chandra error circle of X1624-490, and we propose this source as its IR counterpart. For X1702-429, a Ks = 16.5 ± 0.07 source is visible at the edge of the Chandra error circle. The brightness of both counterpart candidates is comparable to that of other low-mass X-ray binary IR counterparts when corrected for extinction and distance.