Mild evolution of the stellar metallicity gradients of disc galaxies

TISSERA, P. B.; MACHADO, R. E.; VILCHEZ,J. M.; PEDROSA, S.E.; SANCHEZ-BLAZQUEZ, P.; VARELA, S.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2017

0004-6361

Context. The metallicity gradients of the stellar populations in disc galaxies store relevnat information on the disc formation historyand on those processes which could mix stars a posteriori, such as migration, bars and/or galaxy-galaxy interactions. The evolution ofstellar metallicity gradients in disc galaxies, provides strong constraints for the action of these processes and for the improvement ofsubgrid physics modelling of galaxy formation.Aims. We aim to investigate the evolution of the metallicity gradients of the whole stellar populations in disc componentes of simulatedgalaxies in a cosmological context in order to provide constraints to the subgrid physics via predictions which coud be observationallyprobed by forthcoming observations.Methods. We analyse simulated disc galaxies selected from a cosmological hydrodynamical simulation which includes chemicalevolution and a physically motivated Supernova feedback capable of driving mass-loaded galactic winds. We measure the metallicityprofiles of the stellar populations in disc components in the redshift interval z = [0, 1.3]. We also assess the evolution of the gradientsobtained by using the metallicity gradients of mono-age stellar populations at z ∼ 0.Results. We detect a mild evolution in the metallicity slopes of −0.02 ± 0.01 dex kpc −1 from z ∼ 1. This evolution is similar tothat found by using the stellar distributions and their chemical abundances at z ∼ 0. If the metallicity profiles are normalised by theeffective radius of the stellar disc, the slopes show no clear evolution for z < 1, with a median value of approximately −0.23 dex−1r reff. We find evidence of an U-shape distribution between the metallicity gradients and the stellar mass for z < 1. For galaxies withstellar masses