Astronomical Evidence for the Rapid Growth of Millimeter Sized Particles in Protoplanetary Disks

TL;DR

Recent millimeter wavelength surveys reveal rapid growth of millimeter-sized particles in protoplanetary disks, suggesting quick planetesimal formation within about 2 million years, aligning with models and cosmochemical data.

Contribution

This paper synthesizes survey data, models, and cosmochemical evidence to support the idea of swift dust growth in protoplanetary disks, providing a unified view of disk evolution.

Findings

Luminosity distribution declines rapidly, indicating dust growth.

Most disk dust is in millimeter and larger particles within 2 Myr.

Results align with models and cosmochemical measurements.

Abstract

I summarize recent surveys of protoplanetary disks at millimeter wavelengths and show that the distribution of luminosity, equivalent to the mass in small dust grains, declines rapidly. This contrasts with statistics on the lifetime of disks from infrared observations and the high occurrence of planets from radial velocity and transit surveys. I suggest that these disparate results can be reconciled if most of the dust in a disk is locked up in millimeter and larger sized particles within about 2 Myr. This statistical result on disk evolution agrees with detailed modeling of a small number of individual disks and with cosmochemical measurements of rapid planetesimal formation.