Spectroscopy of lensing galaxies in the GTC era
  We are using OSIRIS at the 10.4-m Gran Telescopio CANARIAS (GTC) to obtain spectra of faint galaxies close to multiply imaged quasars. We initially focused on the fields of HE 1413+117 (Cloverleaf quasar) and SDSS 1116+4118. In this contribution, we present long-slit spectroscopy of two galaxies in the southwest of the Cloverleaf, and show that one of them makes a negligible contribution to the external shear of the gravitational lens system. Spectra of the main lensing galaxy candidate in SDSS 1116+4118 are also analysed and discused. If gravitational lensing is causing the quasar image splitting, our spectra reveal that the main lens can not consist of only one dominant galaxy. 
Vyacheslav N. Shalyapin and Luis J. Goicoechea
astro-ph.GA