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Session 47 - Microlensing.
Display session, Tuesday, January 16
North Banquet Hall, Convention Center

[47.10] Determining Cosmological Paramaters using Gravitational Lens Systems with Multiple Giant Arcs

R. Link, M. J. Pierce (Indiana U.)

We investigate the use of gravitational lens systems with multiple giant arcs as a means of determining cosmological parameters. A method for inverting such lens systems embedded in an unknown cosmology is described and we apply it to simulated data. We exploit the fact that sources over a considerable range of redshift can be imaged by the same mass distribution allowing us to separate the effects of the lensing potential and the cosmology.

For cases in which both the redshifts of the arcs and the general form of the lensing potential are known, we find that the cosmology used to simulate the data can indeed be recovered. However, for a poorly known potential (e.g. a smooth cluster potential with superposed "small scale structure") we are unable to recover the cosmological parameters without additional external constraints (a common and known M/L for the individual galaxies, etc.). We conclude that this method could be useful for recovering cosmological parameters provided that the redshifts can be determined for multiple giant arcs in a given system and sufficient care is taken in modelling the details of the lensing potential.

Program listing for Tuesday