An optical time delay for the double gravitational lens system FBQ 0951+2635
Abstract
We present optical R-band light curves of the double gravitationally lensed quasar FBQ 0951+2635 from observations obtained at the Nordic Optical Telescope between March 1999 and June 2001. A time delay of 16 +/- 2 days (1 sigma) is determined from the light curves. New constraints on the lensing geometry are provided by the position and ellipticity of the lensing galaxy. For a (Omega_m, Omega_Lambda) = (0.3, 0.7) cosmology, the time delay yields a Hubble parameter of H_0 = 60^{+9}_{-7} (random, 1 sigma) +/- 2 (systematic) km/s/Mpc for a singular isothermal ellipsoid model and H_0 = 63^{+9}_{-7} (random, 1 sigma) +/- 1 (systematic) km/s/Mpc for a constant mass-to-light ratio model. In both models, the errors are mainly due to the time-delay uncertainties. Non-parametric models yield H_0 = 64^{+9}_{-7} (random, 1 sigma) +/- 14 (systematic) km/s/Mpc.
Keywords
Cite
@article{arxiv.astro-ph/0409444,
title = {An optical time delay for the double gravitational lens system FBQ 0951+2635},
author = {P. Jakobsson and J. Hjorth and I. Burud and G. Letawe and C. Lidman and F. Courbin},
journal= {arXiv preprint arXiv:astro-ph/0409444},
year = {2007}
}
Comments
7 pages, 7 figures. Accepted for publication in A&A