This is a long-term research programme to observe the spatially extended structures around AGN in order to learn about the properties of the host galaxies. A particular technique has been to use the type 2 sources (assumed to the AGN which are obscured from our direct view by either the molecular torus or by optically thick material in the host) which provide their own 'natural coronograph' to remove the glare of the central quasar. Studies of low redshift radio galaxies were carried out in the '80's, resulting in an understanding of the extended emission line properties: physical conditions, chemical composition and kinematics. More recently, work has concentrated on radio galaxies with redshifts around 2.5 which probably represents the epoch where the spheroids were being assembled. The observational programmes have used the Keck spectropolarimeter (LRISp) and the infrared spectrometer/imager on the VLT (ISAAC).
This is a programme which exploits the exquisite image quality of the HST STIS unfiltered mode (50CCD) used in parallel to measure the Cosmic Shear on small angular scales. (PI Peter Schneider, U. Bonn). The dataset will have many other uses. VLT observations are being carried out to make a statistical determination of the redshift distribution of the lensed galaxies (PI Wolfram Freudling, ST-ECF).
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