The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. III. Substructures in Protostellar Disks

TL;DR

This study presents early-stage observations of protostellar disks showing substructures, indicating that such features associated with planet formation can form within the first million years of disk evolution.

Contribution

It provides the first evidence of substructures in very young protostellar disks (0.1-1 Myr), suggesting early formation of features linked to planet or binary formation.

Findings

Substructures are present in disks as young as 0.1 Myr.

Some disks have massive envelopes, indicating their youth.

Inner disk emission is offset, hinting at binary formation processes.

Abstract

The prevalence of substructures in $\sim1-10$ Myr old protoplanetary disks, which are often linked to planet formation, has raised the question of how early such features form, and as a corollary, how early planet formation begins. Here we present observations of seven protostellar disks (aged $\sim0.1-1$ Myr) from the VLA/ALMA Nascent Disk and Multiplicity Survey of Orion Protostars (VANDAM: Orion) that show clear substructures, thereby demonstrating that these features can form early in the lifetimes of disks. We use simple analytic models as well as detailed radiative transfer modeling to characterize their structure. In particular we show that at least four of the sources have relatively massive envelopes, indicating that they are particularly young, likely the youngest disks with substructures known to-date. Several of these disks also have emission from an inner disk that is offset from the center of the ring structure. Given the size of the cleared out regions of the disk, it is unclear, however, whether these features are related to planet formation, or rather if they are signposts of close-separation binary formation at early times.