The Redshift of a Lensing Galaxy in PMN J0134-0931
  The Sloan Digital Sky Survey (SDSS) automatically targeted as a quasar candidate the recently discovered, gravitationally lensed, extremely reddened z=2.2 quasar PMN J0134-0931. The SDSS spectrum exhibits Ca II absorption at z=0.76451, which we identify as the redshift of a lensing galaxy. Hubble Space Telescope imaging shows that components CDE of the system are significantly redder than components A or B and detects faint galaxy emission between D and A+B. The redshift of the dust responsible for the reddening remains unconstrained with current data. However, we outline a model wherein lensing and differential reddening by a z=0.76451 galaxy pair can entirely explain this system. Detecting mm-wave molecular line absorption from the lensing galaxy or galaxies may be possible in PMN J0134-0931, just as in the lenses PKS1830-211 and B0218+357. Well-constructed optical quasar surveys like the SDSS can contribute to the detection and study of reddened quasars. (Expanded) 
Patrick B. Hall (1,2), Gordon T. Richards (3), Donald G. York (4),   Charles R. Keeton (4), David V. Bowen (1), Donald P. Sc...