A maximum-entropy method for reconstructing the projected mass distribution of gravitational lenses

S. L. Bridle, M. P. Hobson, A. N. Lasenby, Richard Saunders

    Research output: Contribution to journalArticlepeer-review

    Abstract

    The maximum-entropy method is applied to the problem of reconstructing the projected mass density of a galaxy cluster using its gravitational lensing effects on background galaxies. We demonstrate the method by reconstructing the mass distribution in a model cluster using simulated shear and magnification data to which Gaussian noise is added. The mass distribution is reconstructed directly and the inversion is regularized using the entropic prior for this positive additive distribution. For realistic noise levels, we find that the method faithfully reproduces the main features of the cluster mass distribution not only within the observed field but also slightly beyond it. We estimate the uncertainties in the reconstruction by calculating an analytic approximation to the covariance matrix of the reconstruction values of each pixel. This result is compared with error estimates derived from Monte Carlo simulations for different noise realizations and found to be in good agreement.
    Original languageEnglish
    Pages (from-to)895-903
    Number of pages8
    JournalMonthly Notices of the Royal Astronomical Society
    Volume299
    Issue number3
    DOIs
    Publication statusPublished - 21 Sep 1998

    Keywords

    • Cosmology: theory
    • Dark matter
    • Galaxies: clusters: general
    • Gravitational lensing
    • Methods: data analysis

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