Stellar Population and Evolution of Galaxies in Groups: the NGC 2300 Group
Using panoramic and long-slit spectroscopy at the 6-m telescope of SAO RAS, we studied the stellar population and kinematics of five early-type disc galaxies-members of the NGC 2300 group. The evolution of galaxies appears to be absolutely out of synch: while the average age of the stars in the central regions of the galaxies located close to the center of the group ranges from 2 to 7 Gyr, the peripheral spiral galaxies have old nuclei and bulges, with the ages of 10-15 Gyr. The brightest galaxy of the NGC 2300 group, which up to now has been considered to be lenticular, of the SA0 type, turned out to be extremely hot dynamically: its bulge rotates slowly, v/σ = 0.06, and the outer parts do not rotate at all. We conclude that the kinematics of the stellar component of NGC 2300 indicates that it is not a disc galaxy, but a triaxial spheroid.