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Title: Analytic models of plausible gravitational lens potentials

Abstract

Gravitational lenses on galaxy scales are plausibly modelled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sersic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasising that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential. We also provide analytic formulae for the lens potentials of Sersic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to bemore » modelled, providing a framework for a fuller investigation of dark matter substructure in galaxies and clusters. Finally we remark on the need for finite mass halo profiles when doing cosmological ray-tracing simulations, and the need for readily-calculable higher order derivatives of the lens potential when studying catastrophes in strong lenses.« less

Authors:
; ;  [1]
  1. Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, PO Box 20450, MS29, Stanford, CA 94309 (United States)
Publication Date:
OSTI Identifier:
22156854
Resource Type:
Journal Article
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2009; Journal Issue: 01; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BARYONS; DENSITY; GALAXIES; GRAVITATIONAL LENSES; MASS; NONLUMINOUS MATTER; SIMULATION; SYMMETRY

Citation Formats

Baltz, Edward A., Marshall, Phil, and Oguri, Masamune. Analytic models of plausible gravitational lens potentials. United States: N. p., 2009. Web. doi:10.1088/1475-7516/2009/01/015.
Baltz, Edward A., Marshall, Phil, & Oguri, Masamune. Analytic models of plausible gravitational lens potentials. United States. doi:10.1088/1475-7516/2009/01/015.
Baltz, Edward A., Marshall, Phil, and Oguri, Masamune. Thu . "Analytic models of plausible gravitational lens potentials". United States. doi:10.1088/1475-7516/2009/01/015.
@article{osti_22156854,
title = {Analytic models of plausible gravitational lens potentials},
author = {Baltz, Edward A. and Marshall, Phil and Oguri, Masamune},
abstractNote = {Gravitational lenses on galaxy scales are plausibly modelled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sersic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasising that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential. We also provide analytic formulae for the lens potentials of Sersic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to be modelled, providing a framework for a fuller investigation of dark matter substructure in galaxies and clusters. Finally we remark on the need for finite mass halo profiles when doing cosmological ray-tracing simulations, and the need for readily-calculable higher order derivatives of the lens potential when studying catastrophes in strong lenses.},
doi = {10.1088/1475-7516/2009/01/015},
journal = {Journal of Cosmology and Astroparticle Physics},
issn = {1475-7516},
number = 01,
volume = 2009,
place = {United States},
year = {2009},
month = {1}
}