Frédéric Courbin, Georges Meylan, Yves Revaz, Malte Tewes
We present accurate time delays for the quadruply imaged quasar HE 0435-1223. The delays were measured from 575 independent photometric points obtained in the R-band between January 2004 and March 2010. With seven years of data, we clearly show that quasar ...
2011