ИСТИНА

Lenticular galaxies lie on the red sequence and are thought to be former spirals having quenched their star formation a few Gyr ago. We have studied the stellar population properties of the nearby lenticulars in groups and in the field and have found that S0 disks differ strongly from the contemporain thin stellar disks of spiral galaxies: they are very old, magnesium-overabundant, and rather metal-poor resembling so the stellar population of the thick disk in our Galaxy. In sparse environments nearby lenticular galaxies possess often extended gaseous disks, and sometimes current star formation can be noticed in the outer ring-like structures. While decoupled kinematics implies the origin of the gas by acquisition from outside, homogeneously solar metallicity of the starforming gas excludes its accretion from the cosmological filaments and poses some problems with its advanced chemical evolution.