The intrinsic shape and dynamical structure of the bulges of lenticular galaxies

Abstract

Several scenarios have been proposed to account for the formation and evolution of galactic bulges and to explain the variety of their observed properties. Both the intrinsic shape and dynamical structure of bulges depend on the mechanisms and timescales of their formation. We are deriving the intrinsic axial ratios of the bulges of a sample of unbarred lenticular galaxies to look for a possible relationship with their known orbital structure. Preliminary results show that the orbits of stars of the triaxial bulge of NGC 4476 are more anisotropic than those in the axisymmetric bulge of NGC 4249 hinting at a different formation process.