The Formation of Low-Mass Binary Star Systems Via Turbulent Fragmentation

TL;DR

This paper investigates how low-mass binary star systems form through turbulent fragmentation, using simulations to identify key parameters influencing their formation mechanisms and multiplicity.

Contribution

It introduces robust parameters to predict binary formation mechanisms and demonstrates turbulent fragmentation as the primary process in low-mass star systems with radiative feedback.

Findings

Turbulent fragmentation dominates binary formation in low-mass stars.

Radiative feedback significantly alters protostellar system parameters.

Parameters remain robust even in marginally resolved disks.

Abstract

We characterize the infall rate onto protostellar systems forming in self-gravitating radiation-hydrodynamic simulations. Using two dimensionless parameters to determine disks' susceptability to gravitational fragmentation, we infer limits on protostellar system multiplicity and the mechanism of binary formation. We show that these parameters give robust predictions even in the case of marginally resolved protostellar disks. We find that protostellar systems with radiation feedback predominately form binaries via turbulent fragmentation, not disk instability, and we predict turbulent fragmentation is the dominant channel for binary formation for low-mass stars. We clearly demonstrate that systems forming in simulations including radiative feedback have fundamentally different parameters than those in purely hydrodynamic simulations.