Chemical evolution of the Milky Way with radial gas flows

Roberto D.Dias da Costa
Departamento de Astronomia – IAG/USP – Brasil

The effect of the bar on the chemical abundance distribution of the inner Milky Way is still to be fully understood. It certainly modifies locally the gravitational potential in the bulge and inner disk, and its presence should induce gas inflows and outflows. In this talk will I describe the results of a chemical evolution model developed at IAG/USP that includes the possible effects of the bar in the distribution of abundances. Results agree with observational constraints derived from a sample of planetary nebulae in the galactic bulge, whose abundances have been derived by our group. They point to an abundance decrease with respect to disk objects, and fit the radial gradient of abundances. The model also includes radial gas flows that contribute to decrease the gradient, in agreement with results derived from other barred spiral galaxies, whose metallicity gradients are smaller than those from non-barred spirals. The profile of the star formation rate in the inner Galaxy can only be reproduced when radial flows are included in the model.

Este coloquio se llevará a cabo el Martes 16/4 a las 14hs en el aula del edificio del IAFE, Ciudad Universitaria.