LENSTOOL: Gravitational Lensing Code for Modeling Mass Distr

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owlice
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LENSTOOL: A Gravitational Lensing Software for Modeling Mass Distribution of Galaxies and Clusters (strong and weak regi

Post by owlice » Thu Feb 03, 2011 9:44 pm

LENSTOOL: A Gravitational Lensing Software for Modeling Mass Distribution of Galaxies and Clusters (strong and weak regime)

Abstract: We describe a procedure for modelling strong lensing galaxy clusters with parametric methods, and to rank models quantitatively using the Bayesian evidence. We use a publicly available Markov chain Monte-Carlo (MCMC) sampler ('Bayesys'), allowing us to avoid local minima in the likelihood functions. To illustrate the power of the MCMC technique, we simulate three clusters of galaxies, each composed of a cluster-scale halo and a set of perturbing galaxy-scale subhalos. We ray-trace three light beams through each model to produce a catalogue of multiple images, and then use the MCMC sampler to recover the model parameters in the three different lensing configurations. We find that, for typical Hubble Space Telescope (HST)-quality imaging data, the total mass in the Einstein radius is recovered with ~1-5% error according to the considered lensing configuration. However, we find that the mass of the galaxies is strongly degenerated with the cluster mass when no multiple images appear in the cluster centre. The mass of the galaxies is generally recovered with a 20% error, largely due to the poorly constrained cut-off radius. Finally, we describe how to rank models quantitatively using the Bayesian evidence. We confirm the ability of strong lensing to constrain the mass profile in the central region of galaxy clusters in this way. Ultimately, such a method applied to strong lensing clusters with a very large number of multiple images may provide unique geometrical constraints on cosmology.

Credit: Kneib, Jean-Paul; Bonnet, Henri; Golse, Ghyslain; Sand, David; Jullo, Eric; Marshall, Phil

Site: https://projets.lam.fr/projects/lenstool/wiki
https://ui.adsabs.harvard.edu/abs/2007NJPh....9..447J

Bibcode: 2011ascl.soft02004K

ID: ascl:1102.004
Last edited by Ada Coda on Mon Oct 26, 2020 1:43 am, edited 1 time in total.
Reason: Updated code entry.
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Re: LENSTOOL: Gravitational Lensing Code for Modeling Mass D

Post by kcd » Sun Sep 08, 2013 1:23 am

Entry updated 09/08/2013: removed old location (http://www.oamp.fr/cosmology/lenstool/) and replaced with URL to new site.

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