Dust Morphology Under Changing Dust Mass Ratios in Protoplanetary Discs

TL;DR

This paper explores how varying dust-to-gas mass ratios affect dust morphology in protoplanetary discs through hydrodynamical simulations, proposing that observed disc structures can help constrain this ratio and improve mass estimates.

Contribution

It introduces a method to use disc morphology to constrain dust-to-gas ratios, enhancing the accuracy of protoplanetary disc mass measurements.

Findings

Dust morphology varies with dust-to-gas ratio in simulations.

Disc structures can inform estimates of dust-to-gas ratios.

Potential to improve total disc mass estimates using morphology.

Abstract

Protoplanetary disc mass is one of the most fundamental properties of a planet-forming system, as it sets the total mass budget available for planet formation. However, obtaining disc mass measurements remain challenging, since it is not possible to directly detect H$_2$, and CO abundance ratios are poorly constrained. Dynamical measurements of the disc mass are now possible, but they are not suited to all discs since the measurements typically require well-behaved emission surfaces. A long-standing method is to obtain continuum flux measurements from the dust emission, and convert to a total disc mass by assumption of the dust-to-gas mass ratio, $\epsilon$. This quantity is poorly constrained in protoplanetary discs. % We investigate the impact of $\epsilon$ on the morphology of planet-containing hydrodynamical simulations of dusty protoplanetary accretion discs, and suggest that if a planet mass estimate can be obtained, then disc morphology could be used to constrain $\epsilon$ in observed systems relative to each other, improving the total disc mass estimates of protoplanetary discs.