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19972004
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astro-ph2004

Strong lensing constraints on the properties of cluster galaxies

Liliya L. R. Williams, Prasenjit Saha

A recently discovered quadruply-imaged QSO, SDSS J1004+4112 (Inada et al. 2003; Oguri et al. 2004) in the core of a galaxy cluster has an unprecedented image separation of…

astro-ph2004

The phase-space density distribution of dark matter halos

Liliya L. R. Williams, Crystal Austin, Eric Barnes +2

High resolution N-body simulations have all but converged on a common empirical form for the shape of the density profiles of halos, but the full understanding of the underlying ph…

astro-ph1999

Cluster Reconstruction from Combined Strong and Weak Lensing

Prasenjit Saha, Liliya L. R. Williams, Hanadi AbdelSalam

The lensing information provided by multiple images, arclets, and statistical distortions can all be formulated as linear constraints on the arrival-time surface, and hence on the…

astro-ph1999

Pixellated Lenses and Estimates of H_0 from Time-delay Quasars

Liliya L. R. Williams, Prasenjit Saha

The largest source of uncertainty in the determination of H_0 from a multiply-imaged QSO system is the unknown mass distribution in the lensing galaxy. Parametric models severely r…

astro-ph1997

Cluster Mass Profile from Lensing

Hanadi M. AbdelSalam, Prasenjit Saha, Liliya L. R. Williams

We propose a new technique to reconstruct non-parametrically the projected mass distribution of galaxy clusters from their gravitational lens effect on background galaxies. The bea…

astro-ph1997

Measurement of the Hubble Constant Via Gravitational Lensing--- A Review of the Jodrell Bank ``Golden Lenses'' Workshop

Liliya L. R. Williams, Paul L. Schechter

Gravitational lensing is now widely and successfully used to study a range of astronomical phenomena, from individual objects, like galaxies and clusters, to the mass distribution…