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SUMMARY:Cosmography with cluster strong lensing - Priyamvada Natarajan (De
 partment of Astronomy\, Yale University)
DTSTART:20101208T160000Z
DTEND:20101208T170000Z
UID:TALK28339@talks.cam.ac.uk
CONTACT:Judith Moss
DESCRIPTION:Current efforts in observational cosmology are focused on\ncha
 racterizing the mass-energy content of the Universe. We present results fr
 om\na geometric test based on strong lensing in galaxy clusters. Based on 
 Hubble\nSpace Telescope images and extensive ground-based spectroscopic fo
 llow-up of\nthe massive galaxy cluster Abell 1689\, we used a parametric m
 odel to\nsimultaneously constrain the cluster mass distribution and dark e
 nergy (DE)\nequation of state. Combining our cosmological constraints with
  those from X-ray\nclusters and the Wilkinson Microwave Anisotropy Probe 5
 -year data\, we find that\ndark matter comprises a fraction Omega_m = 0.25
  ± 0.05 of critical density and\nthat the DE parameter wx = -0.97 ± 0.07
 \, both consistent with results from\nother methods. Inclusion of our meth
 od with all other techniques available\nbrings down the current 2- sigma c
 ontours on the dark energy equation of state\nparameter wx by about 30%\n
LOCATION:Ryle Large Meeting Room\, Kavli Building
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