Abstract details

Secular evolution theory predicts that spheroidal components are formed thanks to bars that can transport gas to the central regions of the galaxies. This activity would trigger the star formation needed to generate galactic bulges. According to this idea, bars at smaller scales may carry material to the galactic center and feed active galactic nuclei. However, nobody has determined if these nested bars are efficient enough to cause that kind of effects: it's absolutely necessary to develop the analysis of their kinematics and stellar populations, not studied so far. On this point, relative populations of different structural components of the galaxy are particularly interesting, as they can indicate the steps of the galactic evolution. This is the key to constrain the models and this is what we present for various double-barred galaxies, after high quality spectra where we have measured suitable spectral indices. First results indicate that nuclear bar hasn't played an important role in the star formation history, but more corrections need to be done (in preparation).