Correlations between the size and the stellar population properties of quiescent galaxies

During the last decades, many authors have put large efforts to shed light on the mechanisms responsible of the generalized growth in size of galaxies, as well as to disentangle the main “driver” of their stellar content. In our study, we aim at stating new constraints on the mechanisms that may drive the growth in size of massive galaxies through the study of the stellar population properties of quiescent galaxies within the stellar mass-size plane. Making use of a sample composed of ~850 quiescent galaxies down to I<=23 from the ALHAMBRA survey with reliable size measurements, we build the distributions of their stellar populations up to redshift z~1; i.e. during the period of time in which this kind of galaxies doubled in size. The stellar content (age, metallicity, extinction, and stellar mass) of galaxies is retrieved via SED-fitting using the multi-band photometry of ALHAMBRA and the code MUFFIT. In this talk, I will show that there are correlations between the stellar population properties of quiescent galaxies and both their stellar masses and sizes since z~1, as well as the implications of these results for the most extended mechanisms proposed for the growth in size of galaxies. In addition, I would also present an interpretation of these results more focused on the consequences for the formation and evolution of galaxies, as different distributions of stellar population parameters in the stellar mass-size plane would point out that the stellar mass is not the only driver of the galaxy assembly.