Galaxies within galaxies in the TIMER survey: stellar populations of inner bars are scaled replicas of main bars

Inner bars are frequent structures in the local Universe and thought to substantially influence nuclear regions of disc galaxies. In this study we explore structure dynamics inner by deriving maps radial profiles their mean stellar population content comparing them previous findings context main bars. To end, exploit observations obtained with integral-field spectrograph MUSE three double-barred galaxies TIMER sample. The results indicate that can be clearly distinguished based on properties alone. More precisely, show significantly elevated metallicities depleted [ α /Fe] abundances. Although they exhibit slightly younger ages compared disc, typical age differences small, except at outer ends. These ends parts, an effect known from as orbital separation. particular, youngest stars (i.e. those lowest velocity dispersion) seem occupy most elongated orbits along (inner) bar major axis. We speculate these distinct could connected morphological feature ansae. Radial metallicity enhancements flat axis, but steeper slopes minor This mixing is also indicates affect distribution stars. summary, line results, appear scaled down versions seen suggests picture a ‘galaxy within galaxy’, discs being dynamically equivalent galaxy discs.