2006/09/19 by R. B. Wayth, Randall B. Wayth, R. L. Webster +1 · 3 citations
Physics and Astronomy · #Adaptive optics and wavefront sensing #Algorithm #Astrophysics #Brightness #Computer science #Computer vision #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #Gravitational lens #Image (mathematics) #Image plane #Lens (geology) #Optics #Physics #Pixel #Point source #Point spread function #Software #Strong gravitational lensing #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.10922.x
published as Mon.Not.Roy.Astron.Soc.372:1187-1207,2006 · 21 pages, 24 figures, appearing in MNRAS. Software available from http://www.cfa.harvard.edu/~rwayth/lensview/Lensview_Home.html
arxiv created 2006/09/19 · openalex publication_date 2006/09/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have developed a new software tool, lensview, for modelling resolved gravitational lens images. Based on the lensmem algorithm, the software finds the best-fitting lens mass model and source brightness distribution using a maximum entropy constraint. The method can be used with any point spread function or lens model. We review the algorithm and introduce some significant improvements. We also investigate and discuss issues associated with the statistical uncertainties of models and model parameters and the issues of source plane size and source pixel size. We test the software on simulated optical and radio data to evaluate how well lens models can be recovered and with what accuracy. For optical data, lens model parameters can typically be recovered with better than 1 per cent accuracy, and the degeneracy between mass ellipticity and power law is reduced. For radio data, we find that systematic errors associated with using processed radio maps, rather than the visibilities, are of similar magnitude to the random errors. Hence analysing radio data in image space is still useful and meaningful. The software is applied to the optical arc HST J15433+5352 and the radio ring MG1549+3047 using a simple elliptical isothermal lens model. For HST J15433+5352, the Einstein radius is 0.525 ± 0.015 arcsec which probably includes a substantial convergence contribution from a neighbouring galaxy. For MG1549+3047, the model has Einstein radius 1.105 ± 0.005 arcsec and core radius 0.16 ± 0.03 arcsec. The total mass enclosed in the critical radius is 7.06 × 1010 M⊙ for our best model. We finish by discussing issues relating to modelling of resolved lens images for this method and some alternatives.