From Pebbles and Planetesimals to Planets and Dust: the Protoplanetary Disk--Debris Disk Connection

TL;DR

This paper models the evolution of protoplanetary disk rings into debris disks, showing that large initial solid masses and modest planetesimal formation efficiencies can explain observed debris disk populations.

Contribution

It introduces a new evolutionary model linking protoplanetary rings to debris disks, constraining physical parameters like planetesimal formation efficiency.

Findings

Bright cold debris disks can originate from massive protoplanetary rings.

The model explains debris disk incidence rates across different luminosities and ages.

Large protoplanetary rings are likely progenitors of observed cold debris disks.

Abstract

The similar orbital distances and detection rates of debris disks and the prominent rings observed in protoplanetary disks suggest a potential connection between these structures. We explore this connection with new calculations that follow the evolution of rings of pebbles and planetesimals as they grow into planets and generate dusty debris. Depending on the initial solid mass and planetesimal formation efficiency, the calculations predict diverse outcomes for the resulting planet masses and accompanying debris signature. When compared with debris disk incidence rates as a function of luminosity and time, the model results indicate that the known population of bright cold debris disks can be explained by rings of solids with the (high) initial masses inferred for protoplanetary disk rings and modest planetesimal formation efficiencies that are consistent with current theories of planetesimal formation. These results support the possibility that large protoplanetary disk rings evolve into the known cold debris disks. The inferred strong evolutionary connection between protoplanetary disks with large rings and mature stars with cold debris disks implies that the remaining majority population of low-mass stars with compact protoplanetary disks leave behind only modest masses of residual solids at large radii and evolve primarily into mature stars without detectable debris beyond 30 au. The approach outlined here illustrates how combining observations with detailed evolutionary models of solids strongly constrains the global evolution of disk solids and underlying physical parameters such as the efficiency of planetesimal formation and the possible existence of invisible reservoirs of solids in protoplanetary disks.