The distribution of stellar population age in galactic bars

Context: Recent analysis of stellar populations in barred galaxies have focused on the spatial distribution of stellar population ages and metallicities. However, barred galaxies are complex objects where dynamical instabilities play a leading role in shaping any spatial distribution.
Aims: The age distribution of stellar populations should thus be analyzed from the two points of view of stellar population evolution and dynamical secular evolution.
Methods: Chemodynamical simulations of single barred galaxies with simple but realistic star formation and feedback recipes are used to produce face-on mass-weighted maps of stellar population ages. Luminosity-weighted maps in V-band are also displayed after calibrating the simulation with mass-to-light ratios provided by a synthesis population model.
Results: It is shown that inside a stellar bar two persistent diametrically opposed regions display a mean age lower than the surrounding average. These two low-age regions are due to the accumulation of young stellar populations trapped on elliptical-like orbits along the bar, near the ultra-harmonic resonance. Age gradients along the bar major-axis are comparable to recent observations. Another low-age region is the outer ring located near the Outer Lindblad Resonance, but the presence and strength of this structure is very time-dependent.