lens candidates and detected CO lines at redshifts of z = 1.577$\pm$0.008 and z = 1.786$\pm$0.005 for SDP.9 and SDP.11 respectively (Lupu et al. 2012). Optical images of the foreground lens with the Keck telescope at g- and i-bands confirmed that their optical profiles are consistent with elliptical galaxies (Negrello et al. 2010).Follow-up observations with the SMA at 880 μm (Bussmann et al. 2013) and with the Hubble Space Telescope at 1.1 and 1.6 micron (Negrello et al. 2014) confirmed them to be lensed galaxies.

Dye et al. (2014) modeled the lensed systems as being lensed by elliptical galaxies at redhift $0.6129\pm0.00005$ and $0.7932\pm0.0012$. The magnification factors $\mu$ are estimated to be 6.29 and 7.89 (8.8 and 10.9 according to Bussmann et al. 2013) respectively for the two galaxies (see table 2 of Negrello et al. 2014 for a comprehensive summary of all the measures flux densities and modeled properties).

The selected objects have 12 and 22 $\mu$m flux densities, measured by the Wide-field Infrared Explorer (WISE; Wright et al. 2010) survey, in ‘excess’ by up to an order of magnitude to what expected from purely star-forming SED templates, thus suggesting the presence of a dust-obscured AGN. However, mid-IR excesses 