I contribute to the estimate of H0 by actively participating to the COSMOGRAIL project (i.e. the COSmological MOnitoring of GRAvItational Lenses) which aims to determine H0 from the measurement of the time delay between the multiple images of more than 30 strongly lensed quasars, using 1.5m-class telescopes. I contributed to most of the time-delay measurements derived to date -Nov 2012- by the collaboration and performed the lens modelling of most of the published systems (Vuissoz et al. 2007, 2008; Courbin et al. 2011). I am currently involved in a large observational effort to gather exquisite data (HST imaging, VLT spectroscopy) for five time-delay lenses. By combining these data with state-of-the-art lens modelling techniques, we aim at measuring H0 with an accuracy better than 4%, comparable to the one from current Baryon Acoustic Peak (BAO), Supernovae (SN) or Cepheids studies (see Suyu et al. 2012 for the results on the first two systems).


Time-delay shifted lightcurves of HE0435-1223 (from Courbin et al. 2011).