Protoplanetary Disks of Binary Systems in Orion

TL;DR

This study investigates how binary star systems in Orion influence the evolution of protoplanetary disks, revealing that disks in binaries tend to evolve faster than those around single stars, even at wide separations.

Contribution

The paper provides observational evidence that binary companions accelerate disk dissipation, challenging previous assumptions about disk evolution at wide binary separations.

Findings

Lower accretion disk fraction in binaries compared to single stars.

Disks in wide binaries (>100AU) evolve faster than expected.

Active accretion signatures are less common in binary components.

Abstract

Dusty primordial disks surrounding young low-mass stars are revealing tracers of stellar and planetary formation. The evolution and lifetime of these disks define the boundary conditions of the mechanisms of planet formation. Stellar companions, however, can significantly change this evolution through their tidal interactions. Stellar evolution and planet formation in binaries have to respond to an environment of truncated, quickly disappearing disks--very different compared to an isolated star environment. In order to investigate details of the influence of binarity on circumstellar disk evolution, we obtained adaptive optics supported near-infrared imaging and spectroscopy of the individual components of 22 low-mass binaries in the well-known Orion Nebula Cluster. Brackett gamma emission, which we detect in several systems, is used as a tracer for the presence of an active accretion disk around each binary component. We find a low fraction of accreting binary components, when compared to the disk fraction of single stars in the ONC. This might indicate a significantly faster evolution of disks in binaries. This finding is paticularly interesting, since the target sample consists of wide >100AU binaries--separations for which the disks are typically expected to evolve similarly to single star disks.