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Home List of Titles Shape, shear and flexion: an analytic flexion formalism for realistic mass profiles
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/60722
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- Shape, shear and flexion: an analytic flexion formalism for realistic mass profiles
- Lasky, P. D.; Fluke, C. J.
- Flexion is a non-linear gravitational lensing effect that arises from gradients in the convergence and shear across an image. We derive a formalism that describes non-linear gravitational lensing by a circularly symmetric lens in the thin-lens approximation. This provides us with relatively simple expressions for first- and second-flexion in terms of only the surface density and projected mass distribution of the lens. We give details of exact lens models, in particular providing flexion calculations for a Sersic-law profile, which has become increasingly popular over recent years. We further provide a single resource for the analytic forms of convergence, shear, first- and second-flexion for the following mass distributions: a point mass, singular isothermal sphere (SIS); Navarro-Frenk-White (NFW) profile; Sersic-law profile. We quantitatively compare these mass distributions and show that the convergence and first-flexion are better indicators of the Sersic shape parameter, while for the concentration of NFW profiles the shear and second-flexion terms are preferred.
- Publication type
- Journal article
- Research centre
- Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing
- Monthly Notices of the Royal Astronomical Society, Vol. 396, no. 4 (Jul 2009), pp. 2257-2268
- Publication year
- FOR Code(s)
- 0201 Astronomical and Space Sciences
- Dark matter; Galaxy haloes; Gravitational lensing
- Wiley-Blackwell Publishing
- Publisher URL
- Copyright © 2009 The Authors. Journal compilation copyright © 2009 Royal Astronomical Society. The accepted manuscript is reproduced in accordance with the copyright policy of the publisher. The definitive publication is available at www.interscience.wiley.com.
- Research Projects
The Commonwealth cosmology initiative: from the first objects to the cosmic web, Australian Research Council grant number DP0665574
- Full text
- Peer reviewed