GEPI

The plurality of existing galaxies in today’s Universe remains in many facets an enigma in terms of their individual formation and evolutionary histories. While merging processes seem to have been especially dominant in the early Universe, the accelerating expansion of it is drawing galaxies further apart and internal processes due to their own morphology start having a crucial influence. One of the main drivers of this so-called ‘secular evolution’ are bars. Their significant departure from axisymmetry and the associated torques are responsible for their ability to redistribute angular momentum among the host galaxy as well as drive gas towards the center triggering star formation and/or building up a central mass concentration. We use integral field observations in combination with N-body simulations in order to better understand and quantify their influence in nearby galaxies. While the effect of bars on global galaxy parameters seems to be marginal, they seem to have a crucial influence in certain regions (resonance points), in particular altering the bulge and central. Our in-depth analyses using kinematics and stellar populations support the longevity of bars, their similarity to the bulge and difference to the disk as a structure rotating as a cylinder within the host galaxy.