Wednesday

I will present new results about the morphological evolution of Ha-selected star-forming galaxies. Knowing that the perceived evolution can be affected by a range of biases and systematics, we use an artificial redshifting code which includes the luminosity evolution function for Ha to quantify the change on the measured structural parameters with redshift. We run GALFIT on the scientific and simulated images and we find that star-forming galaxies have grown on average by a factor 2-3 and have Sérsic indices close to pure exponential disks (n~1.2) from z=2.23 to z=0. We trace the rest-frame blue/UV light and we believe that we are witnessing the growth of regions where star-formation occurs in galaxies. These results (Paulino-Afonso et al., 2017) contrast with the ones found by Stott et al. (2013) where, using red/NIR data and the same high-redshift sample, a mild to no evolution trend in galaxies sizes is shown. Why have we not a common view? Do young and old stellar populations evolve in different ways? Do we still need to look at morphology to understand galaxy evolution?