Disk Dispersal: Theoretical Understanding and Observational Constraints

TL;DR

This paper reviews the current theoretical models and observational evidence concerning the rapid dispersal of protoplanetary disks, emphasizing how these processes influence planet formation within a few million years.

Contribution

It synthesizes existing theories and observations on disk dispersal mechanisms, highlighting their implications for planet formation and identifying future research directions.

Findings

Photoevaporation significantly contributes to disk dispersal.

Disks can survive for a few million years despite dispersive effects.

Observational constraints support the importance of UV and X-ray irradiation.

Abstract

Protoplanetary disks dissipate rapidly after the central star forms, on time-scales comparable to those inferred for planet formation. In order to allow the formation of planets, disks must survive the dispersive effects of UV and X-ray photoevaporation for at least a few Myr. Viscous accretion depletes significant amounts of the mass in gas and solids, while photoevaporative flows driven by internal and external irradiation remove most of the gas. A reasonably large fraction of the mass in solids and some gas get incorporated into planets. Here, we review our current understanding of disk evolution and dispersal, and discuss how these might affect planet formation. We also discuss existing observational constraints on dispersal mechanisms and future directions.