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arXiv · astro-ph/0104414

Beware the Non-uniqueness of Einstein Rings

Prasenjit Saha·Liliya L. R. Williams
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Abstract

We explain how an approximation to the rings formed by the host galaxies in lensed QSOs can be inferred from the QSO data alone. A simple ring image can be made from any lens model by a simple piece of computer graphics: just plot a contour map of the arrival-time surface with closely-spaced contours. We go on to explain that rings should be (a) sensitive to time-delay ratios between different pairs of images, but (b) very insensitive to H_0. We illustrate this for the well-known quads 1115+080 and 1608+656.

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Prasenjit Saha, Liliya L. R. Williams. 2001-04-25. Beware the Non-uniqueness of Einstein Rings. https://doi.org/10.1086/321151

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