Chemical evolution of galaxies: emerging dust and the different gas phases in a new multiphase code

Abstract

ABSTRACT Dust plays an important role in the evolution of a galaxy, as it is one of the main ingredients for efficient star formation. Dust grains are also a sink/source of metals when they are created/destroyed, and, therefore, a self-consistent treatment is key in order to correctly model chemical evolution. In this work, we discuss the implementation of dust physics in our current multiphase model, which also follows the evolution of atomic, ionized and molecular gas. Our goal is to model the conversion rates among the different phases of the interstellar medium, including the creation, growth and destruction of dust, based, as far as possible, on physical principles rather than on phenomenological recipes. We first present the updated set of differential equations and then discuss the results. We calibrate our model against observations of the Milky Way Galaxy and compare its predictions with extant data. Our results are broadly consistent with the observed data for intermediate and high metallicities, but the models tend to produce more dust than is observed in the low-metallicity regime.