NOAO > Observing Info > Approved Programs > 2013A-0135
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NOAO > Observing Info > Approved Programs > 2013A-0135 |
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PI: Tommaso Treu, UC Santa Barbara, tt@physics.ucsb.edu
Address: Department of Physics, Broida Hall, Building 572, Santa Barbara, CA, 93106-9530, USA
CoI: Sherry Suyu, UC Santa Barbara
CoI: Chris Fassnacht, UC Davis
CoI: Stefan Hilbert, Stanford University
CoI: Dominique Sluse, Bonn
CoI: Frederic Courbin, Lausanne
Title: Spectroscopic study of the environment of two time-delay lenses for accurate cosmology
Abstract:
We are conducting a program to achieve compelling and robust cosmographic
measurements from five gravitationally lensed quasars with exquisite
time-delays and HST images. We aim with this analysis to measure H_0 with an
accuracy better than 3.8%, resulting in constraints on cosmological
parameters comparable to the one from current BAO and SN work when combined
with CMB data. To reach this goal, we need to track any source of errors. The
analysis of the first two systems has shown that H_0 can be derived from a
single lens with better than 7% accuracy, and that the main source of
uncertainty come from the lens environment. In this proposal, we propose to
obtain multi-object spectroscopy of the galaxies in the field of two
time-delays lenses in order to measure their redshift (spread over 2013A/B).
This will pin down the error from the environment to a few percent, allowing
us to deliver state of the art constraints on cosmological parameters.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2013A-0135 |
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