Skip to main content

Research Repository

Advanced Search

The “External” Shears In Strong Lens Models

Nightingale, James W.; Etherington, Amy; Massey, Richard

The “External” Shears In Strong Lens Models Thumbnail


Authors



Abstract

The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power law plus ‘external shear’, which notionally accounts for line-of-sight galaxies and cosmic shear. We argue that it does not, using three lines of evidence from the analysis of 54 galaxy-scale strong lenses: (i) strong lensing external shears do not correlate with weak lensing; (ii) the measured shear magnitudes in strong lenses (which are field galaxies) are too large (exceeding 0.05) for their environment and; (iii) the external shear position angle preferentially aligns or anti-aligns with the mass model position angle, indicating an internal origin. We argue the measured strong lensing shears are therefore systematically accounting for missing complexity in the canonical elliptical power-law mass model. If we can introduce this complexity into our lens models, this will further lensing studies of galaxy formation, dark matter and Cosmology.

Citation

Nightingale, J. W., Etherington, A., & Massey, R. (2022). The “External” Shears In Strong Lens Models. Proceedings of the International Astronomical Union, 18(S381), 13-16. https://doi.org/10.1017/s1743921323003691

Journal Article Type Article
Acceptance Date Feb 2, 2024
Online Publication Date Mar 4, 2024
Publication Date 2022-12
Deposit Date Mar 11, 2024
Publicly Available Date Mar 11, 2024
Journal Proceedings of the International Astronomical Union
Print ISSN 1743-9213
Electronic ISSN 1743-9221
Publisher Cambridge University Press
Peer Reviewed Peer Reviewed
Volume 18
Issue S381
Pages 13-16
DOI https://doi.org/10.1017/s1743921323003691
Keywords Astronomy and Astrophysics; Space and Planetary Science
Public URL https://durham-repository.worktribe.com/output/2325165

Files




You might also like



Downloadable Citations