A new hybrid framework to efficiently model lines of sight to gravitational lenses

Curtis McCully, Charles R. Keeton, Kenneth C. Wong, Ann I Zabludoff

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

In strong gravitational lens systems, the light bending is usually dominated by one main galaxy, but may be affected by other mass along the line of sight (LOS). Shear and convergence can be used to approximate the contributions from less significant perturbers (e.g. those that are projected far from the lens or have a small mass), but higher order effects need to be included for objects that are closer or more massive. We develop a framework for multiplane lensing that can handle an arbitrary combination of tidal planes treated with shear and convergence and planes treated exactly (i.e. including higher order terms). This framework addresses all of the traditional lensing observables including image positions, fluxes, and time delays to facilitate lens modelling that includes the non-linear effects due to mass along the LOS. It balances accuracy (accounting for higher order terms when necessary) with efficiency (compressing all other LOS effects into a set of matrices that can be calculated up front and cached for lens modelling). We identify a generalized multiplane mass sheet degeneracy, in which the effective shear and convergence are sums over the lensing planes with specific, redshift-dependent weighting factors.

Original languageEnglish (US)
Pages (from-to)3631-3642
Number of pages12
JournalMonthly Notices of the Royal Astronomical Society
Volume443
Issue number4
DOIs
StatePublished - 2014

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gravitational lenses
line of sight
lenses
shear
compressing
modeling
time lag
galaxies
matrix
matrices
effect

Keywords

  • Gravitational lensing: strong
  • Gravitational lensing: weak

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

A new hybrid framework to efficiently model lines of sight to gravitational lenses. / McCully, Curtis; Keeton, Charles R.; Wong, Kenneth C.; Zabludoff, Ann I.

In: Monthly Notices of the Royal Astronomical Society, Vol. 443, No. 4, 2014, p. 3631-3642.

Research output: Contribution to journalArticle

McCully, Curtis ; Keeton, Charles R. ; Wong, Kenneth C. ; Zabludoff, Ann I. / A new hybrid framework to efficiently model lines of sight to gravitational lenses. In: Monthly Notices of the Royal Astronomical Society. 2014 ; Vol. 443, No. 4. pp. 3631-3642.
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