The Effects of Radiation Feedback on Early Fragmentation and Multiplicity

TL;DR

This study uses advanced simulations to show that radiation feedback significantly influences star formation, reducing disk fragmentation and suggesting turbulence as the main source of low-mass binary stars.

Contribution

It demonstrates for the first time that radiation feedback suppresses disk fragmentation in low-mass star formation simulations.

Findings

Radiation feedback reduces disk fragmentation.

Turbulent fragmentation likely causes low-mass binaries.

Heating effects are confined within the core envelope.

Abstract

Forming stars emit a significant amount of radiation into their natal environment. While the importance of radiation feedback from high-mass stars is widely accepted, radiation has generally been ignored in simulations of low-mass star formation. I use ORION, an adaptive mesh refinement (AMR) three-dimensional gravito-radiation-hydrodynamics code, to model low-mass star formation in a turbulent molecular cloud. I demonstrate that including radiation feedback has a profound effect on fragmentation and protostellar multiplicity. Although heating is mainly confined within the core envelope, it is sufficient to suppress disk fragmentation that would otherwise result in low-mass companions or brown dwarfs. As a consequence, turbulent fragmentation, not disk fragmentation, is likely the origin of low-mass binaries.