Revealing the spiral arms through radial migration and the shape of the Metallicity Distribution Function

L. A. Martinez-Medina, B. Pichardo, E. Moreno, A. Peimbert

Published 2016-04-06Version 1

Recent observations show that the Milky Way's metallicity distribution function (MDF) changes its shape as a function of radius. This new evidence of radial migration within the stellar disc sets additional constrains on Galactic models. By performing controlled test particle simulations in a very detailed, observationally motivated model of the Milky Way, we demonstrate that, in the inner region of the disc, the MDF is shaped by the joint action of the bar and spiral arms, while at outer radii the MDF is mainly shaped by the spiral arms. We show that the spiral arms are able to imprint their signature in the radial migration, shaping the MDF in the outskirts of the Galactic disc with a minimal participation of the bar. Conversely, this work has the potential to characterize some structural and dynamical parameters of the spiral arms based on radial migration and the shape of the MDF.