P.G. Edwards , J.E.J. Lovell , H. Hirabayashi , D.L. Jauncey S. Toft, PASA, 18 (2), in press.
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Lens Modelling
As their PSF-subtraction and the deconvolution reductions yielded differing positions for the lensing galaxy, Toft et al. (2000) undertook preliminary modeling of the lens system to see which of the two positions was more plausible. The modeling revealed that the image configuration could not be reproduced using the position of the galaxy derived from the deconvolution, but that the position derived from PSF-subtracted imaged provided a reasonable fit.
Toft et al. (2000) modeled the lens system assuming a standard dark halo as the dominating lens mass, and derived a time delay of 
60 days for the lensing system. No attempt was made to quantify the uncertainty in this value due to the degenerate nature of the problem resulting from the lack of observational constraints, with the main uncertainty being the unknown projected position of the lensing galaxy.
We have commenced modelling of this system using the gravlens code (Keeton 2001). Use of a Singular Isothermal Sphere with the galaxy position and mass allowed to vary gave acceptable fits to the positions and flux densities of components A and B. The resulting galaxy position was located at a
with respect to component A of (0.69,-0.94), which is only 0.15arcseconds from the best-fit position from the Toft et al. (2000) modelling. The derived time delays for this model were 50.4 days for 
=1.0, 
=0.0, and 52.6 days for =0.3, =0.7, with an assumed H0 of 75kms-1Mpc-1. The lack of additional constraints on the system precludes any meaningful attempt to determine the range of possible delays at this stage.
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Title/Abstract Page: The Structure of the
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