AAS Meeting #193 - Austin, Texas, January 1999
Session 117. Gravitational Lensing
Oral, Saturday, January 9, 1999, 2:00-3:30pm, Ballroom B

[Previous] | [Session 117] | [Next]

[117.03D] Measuring Cosmological Parameters Using Gravitational Lens Systems: a new technique

R. Link (Indiana University)

Recent HST images of gravitational lens systems suggest that multiple sources at different redshifts may be lensed by a single cluster. We have developed a new technique for extracting the cosmological parameters \Omega and \lambda from these multiple-arc gravitational lenses. Requiring a consistent mass model for sources at different redshifts resolves the ambiguity between the effects of the overall scale factor in the lens mass distribution and the effects of the cosmological parameters in the angular~size-redshift relation.

This dissertation details this method for measuring \Omega and \lambda. The cosmological parameters are included as model parameters to be fit to the observations, and a merit function that measures the deviation in surface brightness between multiple images of a single source pixel is minimized to produce a best fit model. Applying the method to simulated data we find that in general models over a broad range of \Omega and \lambda can fit the data. However, within the families of flat and \lambda=0 models the cosmological parameters are well-constrained. Our Monte Carlo error calculation indicates that for flat cosmologies the method can recover \lambda to within ±0.2 for reasonable measurement uncertainties in the arcs' redshifts. Thus, we believe this method will make an excellent complement to existing techniques for measuring cosmological parameters.

If you would like more information about this abstract, please follow the link to http://www.astro.indiana.edu/personnel/link/work.html. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

The author(s) of this abstract have provided an email address for comments about the abstract: link@astro.indiana.edu

[Previous] | [Session 117] | [Next]