During September 2002, a team from AIP used the new Potsdam Multi-Aperture Spectrophotometer (PMAS) to observe a spectacular gravitational lens. The PMAS instrument, attached to the 3.5-m telescope on Calar Alto/Spain, allows the observer to obtain images and spectra simultaneously. This is done by catching the light at the telescope focal plane in thin glas fibres, which are then coupled to a high-performance spectrograph. The reddish blob in the centre between the four quasar images is the foreground galaxy whose mass distorts the light rays of the quasar behind it.

L. Wisotzki
more at http://www.aip.de/highlight_archive/wisotzki/index.html  (image added 2003-11-20)

The image shows the decomposed on-nucleus long-slit spectrum components for the z=0.158 quasar HE1503+0228 (VLT FORS1). The green line is derived from the difference between total and nucleus spectrum. It is enlarged in the lower panel. Visible are stellar absorption features as the Ca doublet and the G-band and narrow gas emission lines as [OIII] and narrow H_beta. The spectrum is perfectly normal fpr a spiral galaxy with ongoing star formation.
K. Jahnke, L. Wisotzki
more at http://www.aip.de/~jahnke/research.html  (image added 2003-01-29)

Field around the quasar B3 0740+380C (arrow) from a combination of B, R and K band images. The field of view is 5'x6'. The excess of red galaxies clustering around the quasar are clearly seen. There is also some fuzzy emission around the quasar indicating the presence of the host galaxy. Such clustering was found near six other quasars. It is suggested that mergings are the origin or feeding mechanism for the active nuclei of quasars.
S.S. Sánchez Sánchez, J.I. Gónzalez-Serrano
more at http://www.aip.de/groups/opti/pmas/OptI.html  (image added 2003-01-29)