Combining Strong and Weak Gravitational Lensing in Abell 1689

We present a reconstruction of the mass distribution of galaxy cluster Abell1689 at z = 0.18 using detected strong lensing features from deep HST/ACSobservations and extensive ground based spectroscopy. Earlier analyses havereported up to 32 multiply imaged systems in this cluster, of which only 3 werespectroscopically confirmed. In this work, we present a parametric stronglensing mass reconstruction using 24 multiply imaged systems with newlydetermined spectroscopic redshifts, which is a major step forward in building arobust mass model. In turn, the new spectroscopic data allows a more secureidentification of multiply imaged systems. The resultant mass model enables usto reliably predict the redshifts of additional multiply imaged systems forwhich no spectra are currently available, and to use the location of thesesystems to further constrain the mass model. In particular, we have detected 5strong galaxy-galaxy lensing systems just outside the Einstein ring region,further constraining the mass profile. Our strong lensing mass model isconsistent with that inferred from our large scale weak lensing analysisderived using CFH12k wide field images. Thanks to a new method for reliablyselecting a well defined background lensed galaxy population, we resolve thediscrepancy found between the strong and weak lensing mass models reported inearlier work. [ABRIDGED]