Publication

Galaxy Groups Associated with Gravitational Lenses and H0 from B1608+656

Fassnacht, C., Lubin, L., McKean, J., Gal, R., Squires, G., Koopmans, L., Treu, T., Blandford, R. & Rusin, D., 1-Jun-2005, Impact of gravitational lensing on cosmology: Proceedings of the 225th Symposium of the International Astronomical Union held at the Ecole Polytechnique Federale de Lausanne Switzerland July 19-23, 2004. Mellier, Y. & Meylan, G. (eds.). Cambridge University Press, Vol. 225. p. 311-317 (Proceedings of the International Astronomical Union; vol. 225).

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademic

Compact groups of galaxies recently have been discovered in association with several strong gravitational lens systems. These groups provide additional convergence to the lensing potential and thus affect the value of H0 derived from the systems. Lens system time delays are now being measured with uncertainties of only a few percent or better. Additionally, vast improvements are being made in incorporating observational constraints such as Einstein ring structures and stellar velocity dispersions into the lens models. These advances are reducing the uncertainties on H0 to levels at which the the effects of associated galaxy groups may contribute significantly to the overall error budget. We describe a dedicated multiwavelength program, using Keck, HST, and Chandra, to find such groups and measure their properties. We present, as a case study, results obtained from observations of the CLASS lens system B1608+656 and discuss the implications for the value of H0 derived from this system.
Original languageEnglish
Title of host publicationImpact of gravitational lensing on cosmology
Subtitle of host publicationProceedings of the 225th Symposium of the International Astronomical Union held at the Ecole Polytechnique Federale de Lausanne Switzerland July 19-23, 2004
EditorsYannick Mellier, Georges Meylan
PublisherCambridge University Press
Pages311-317
Volume225
ISBN (Print)0521851963, 9780521851961
Publication statusPublished - 1-Jun-2005
EventIAU Symposium 225: Impact of gravitational lensing on cosmology - Lausanne, Switzerland
Duration: 19-Jul-200423-Jul-2004

Publication series

NameProceedings of the International Astronomical Union
Volume225
ISSN (Print)1743-9213

Conference

ConferenceIAU Symposium 225: Impact of gravitational lensing on cosmology
CountrySwitzerland
CityLausanne
Period19/07/200423/07/2004

Event

IAU Symposium 225: Impact of gravitational lensing on cosmology

19/07/200423/07/2004

Lausanne, Switzerland

Event: Conference

ID: 26633852