Journal Article

Weak lensing by line-of-sight haloes as the origin of flux-ratio anomalies in quadruply lensed QSOs

Kaiki Taro Inoue and Ryuichi Takahashi

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 426, issue 4, pages 2978-2993
Published in print November 2012 | ISSN: 0035-8711
Published online November 2012 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2012.21915.x
Weak lensing by line-of-sight haloes as the origin of flux-ratio anomalies in quadruply lensed QSOs

More Like This

Show all results sharing this subject:

  • Astronomy and Astrophysics

GO

Show Summary Details

Preview

Abstract

We explore the weak lensing effect by line-of-sight haloes and subhaloes with a mass of M ≲ 107 M in Quasi-Stellar Object (QSO)–galaxy strong lens systems with quadruple images in a concordant Λ cold dark matter universe. Using a polynomially fitted non-linear power spectrum P(k) obtained from N-body simulations that can resolve haloes with a mass of M ∼ 105 M, or structures with a comoving wavenumber of k ∼ 3 × 102h Mpc−1, we find that the ratio of magnification perturbation due to intervening haloes to that of a primary lens is typically ∼10 per cent and the predicted values agree well with the estimated values for six observed QSO–galaxy lens systems with quadruple images in the mid-infrared band without considering the effects of substructures inside a primary lens. We also find that the estimated amplitudes of convergence perturbation for the six lenses increase with the source redshift as predicted by theoretical models. Using an extrapolated matter power spectrum, we demonstrate that small haloes or subhaloes in the line of sight with a mass of M = 103–107 M, or structures with a comoving wavenumber of k = 3 × 102–104h Mpc−1, can significantly affect the magnification ratios of the lensed images. Flux-ratio anomalies in QSO–galaxy strong lens systems offer us a unique probe into the clustering property of minihaloes with a mass of M < 106 M.

Keywords: galaxies: formation; cosmology: theory; dark matter

Journal Article.  13057 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.