Spectral study of star-forming rings in S0 galaxies of Dorado group – NGC 1533 and NGC 1543

Abstract

ABSTRACT We have fulfilled a detailed long-slit spectroscopic analysis for two SB0 galaxies – NGC 1533 and NGC 1543, – belonging to the Dorado group. Our spectral data reveal asymmetric decoupled kinematics of the stars and ionized gas in these barred lenticular galaxies that give evidences for external origin of the gas in the rings. We have calculated the star formation rates in the rings by using the ultraviolet fluxes of the rings corrected for the foreground and intrinsic absorption; and we have estimated parameters of the stellar populations in the inner parts of the galaxies confirming that they are old – except the nucleus of NGC 1543, which demonstrates signatures of rejuvenation less than 5 Gyr ago.