Evolution of dust abundance and grain size distribution at high redshift

Abstract

We report our recent theoretical work on the evolution of grain size distribution and grain abundance, particularly focusing on high-redshift (high-z) galaxies. We consider dust production in supernovae and shattering in interstellar turbulence. We show that observed extinction curves at high z can be reproduced if the dust supplied from supernovae is processed by shattering in interstellar turbulence. We also calculate the evolution of grain abundance and compare our theoretical results with the observed dust abundances in high-redshift quasars. We find that shattering is crucial to activate grain mass increase by the accretion of gas-phase metals since small-grain production by shattering raises the grain growth rate significantly. This means that the evolution of grain size distribution plays a critical role in governing the dust abundance at high z.