The rapid burster in Liller 1: The Chandra X-ray position and a search foran infrared counterpart

Despite the unique X-ray behavior of the compact bursting X-ray source MXB 1730-335, the "Rapid Burster II (RB) in the highly reddened globular cluste r Liller 1, to date there has been no known optical/ IR counterpart for the object, no precise astrometric solution that correlates X-ray, radio, and optical positions and thus restricts the number of possible candidates, nor even published IR images of the field. We solve a previous radio/X-ray pos itional discrepancy, presenting the results of precise Chandra X-ray imagin g, which definitively show that the radio source is positionally aligned wi th MXB 1730-335. At the same time, we have detected three additional low-lu minosity (L-x similar to 10(34) ergs s(-1)) X-ray sources within two core r adii, which are possibly quiescent low-mass X-ray binaries. We present both ground-based and Hubble Space Telescope (HST) infrared imaging of the fiel d (in quiescent and bursting X-ray states of the RB), together with the nec essary astrometric solution to overlay the radio/X-ray source positions. Ev en at HST resolution, the RB field is very complex and there are multiple c andidates. No object of unusual color or of substantial variability in quie scent versus active or burst versus nonburst states is identified. Further, more sensitive HST NICMOS and/or ground-based, adaptive optics observation s are needed to confidently identify the proper counterpart. In the case of the RB, uncertain but plausible calculations on the effects of the burst o n the binary companion indicate that detection of a variable candidate shou ld be feasible.