ИСТИНА

The general view of galaxy formation and evolution includes bars as the major drivers of the internal secular evolution of galaxies. The bars are very frequent phenomena: about one-third of all disk galaxies are strongly barred and an additional one-third are moderately barred. Often bars in galaxies are accompanied by rings and ansae phenomena at the end of bars. The ansae are bright enhancements at the ends of bar which are thought to be formed in the secular evolution phase (> 5Gyr) of disk galaxies. The ansae are frequent phenomena since 40% of early-type disk galaxies reveal this feature but their properties and dynamical significance are still poorly understood. Based on the optical spectroscopic observations at SALT (South Africa) telescope we studied the stellar populations of ansae regions in 7 barred disk galaxies. All considered galaxies possess rings at the end of bars except one where the ring is less prominent. We found that ansae regions are significantly distinguished in the stellar metallicities in all galaxies. At the same time these regions do not reveal peculiarities in the stellar age profile. We discussed how these findings provide additional important information that should be taken into account for detailed gaseous-stellar dynamical models to restrict the bar evolution.