Can planet formation resolve the dust budget crisis in high-redshift galaxies?

Abstract

The process of planet formation offers a rich source of dust production via grain growth in protostellar discs, and via grinding of larger bodies in debris disc systems. Chemical evolution models, designed to follow the build up of metals and dust in galaxies, do not currently account for planet formation. We consider the possibility that the apparent underprediction of dust mass in high-redshift galaxies by chemical evolution models could be in part, due to these models neglecting this process, specifically due to their assumption that a large fraction of the dust mass is removed from the interstellar medium during star formation (so-called astration). By adding a planet formation phase into galaxy chemical evolution, we demonstrate that the dust budget crisis can be partially ameliorated by a factor of 1.3–1.5 only if (i) circumstellar discs prevent a large fraction of the dust mass entering the star during its birth, and (ii) that dust mass is preferentially liberated via jets, winds and outflows rather than accreted into planetary-mass bodies.