1999/05/19 by Peter Newbury, P. Newbury, Newbury, P. +2
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astrophysics (astro-ph) #FOS: Physical sciences #Geophysics and Gravity Measurements #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9905254
25 pages, including 10 PostScript Figures and 6 deluxetable Tables. LaTeX2e with aaspp4 (AAS-TeX v4.0). Submitted to ApJ
arxiv created 1999/05/19 · openalex publication_date 1999/05/19 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We propose a new, two-stage algorithm for inverting strong gravitational lenses. The key to the algorithm is decoupling the effects of lens magnification and intrinsic structure in the background source in the appearance of lensed arcs. First, the distribution of mass on the deflector plane and the geometry of the source-deflector-observer optical system are established. This is done by numerically simulating the lensing of light past a parametric mass model, and adjusting the handful of model parameters to match the positions and shapes of the observed and simulated lensed arcs. At the same time, this determines the magnification of the background source induced by the lensing process. The predicted magnification is then removed from the data to reveal the intrinsic, though still distorted, background distribution of light. After tracing each lensed ray back to the source plane, the data are combined to produce a surface brightness distribution of the source. This two-stage inversion scheme produces a parametric model of the deflector and a pixelized rendering of the background source which together mimic the observed gravitationally lensed features. We test the viability of scheme itself on a well-studied collection of lensed objects in the galaxy-cluster MS 2137. Confident in the algorithm, we apply it second time to predict the distribution of mass in the galaxy-cluster MS 1455 responsible for an observed triplet of lensed arcs. Our predictions about the lens in MS 1455 make it particularly interesting, for a single background source is responsible for both tangential arcs and a radial arc.