Ten years of nearby galaxies research with the multi-pupil spectrograph of the 6m telescope

We describe the history and results of our study of early-type disk galaxies with the Multi-Pupil Spectrograph of the SAO 6m telescope (MPFS). With the new data we confirm the discovery of chemically distinct nuclei reported in 1992; now, such nuclei are found in two dozens of galaxies. The structure of chemically distinct features formed probably in secondary nuclear star-formation bursts seems to be complex and closely related to an appearance of separate circumnuclear disks. As by-product, we have also found inner polar gaseous disks in four non-interacting, regular spiral galaxies; this phenomenon may be related to triaxiality. Some preliminary statistical conclusions on the stellar population properties in the nuclei and in the bulges of S0 galaxies are given.