Dating Secular Evolution: Bar Ages from Stellar Kinematics

The last few years witnessed a change of perspective in the context of galaxy formation and evolution. The major role played by bars in the history of these fundamental building blocks of our universe was finally realized. However, and despite the fact that one of the major concerns of any physical science is to measure timescales for natural phenomena, we have as yet no established way to estimate the ages of these important galactic components. In this contribution we outline the method we developed to estimate bar ages and briefly describe its first results. 1 Why do we need bar ages? It is now generally accepted that bars make substantial changes to the destiny of most disk galaxies [7]. The development of a method that enables us to measure for how long a bar is present in its host galaxy is thus of primary relevance. Fundamental questions can be better addressed or even answered with such a method at hand, including: To what extent bars are relevant to the building of bulges and its variations [1]? How exactly the processes induced by bars contribute to the stellar and non-stellar nuclear activities in disk galaxies [6]? When did the first bars appear [3]? Are bars a recurrent phenomenon [2]? Or are they a robust, perennial galactic structure [9]?