2006/08/24 by P. Saha, Prasenjit Saha, Liliya L. R. Williams +1 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gravitation #Gravitational lens #Gravitational lensing formalism #Magnification #Parametric statistics #Stellar, planetary, and galactic studies #Strong gravitational lensing #astro-ph
paper · pdf · doi:10.1086/508798
published as Astrophys.J.653:936-941,2006 · To appear in ApJ
arxiv created 2006/08/24 · openalex publication_date 2006/12/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In gravitational lensing, steeper mass profiles generically produce longer time delays but smaller magnifications, without necessarily changing the image positions or magnification ratios between different images. This is well known. We find in this paper, however, that even if steepness is fixed, time delays can still have significant model dependence, which we attribute to shape-modeling degeneracies. This conclusion follows from numerical experiments with models of 35 galaxy lenses. We suggest that varying and twisting ellipticities, features that are explored by pixelated lens models but not, so far, by parametric models, has an important effect on time delays.