The formation of brown dwarfs in discs: Physics, numerics, and observations

TL;DR

This paper investigates how brown dwarfs and low-mass stars can form through gravitational fragmentation of massive, extended discs around Sun-like stars, using radiative hydrodynamic simulations to explain observed stellar properties.

Contribution

It provides a comprehensive simulation-based analysis of disc fragmentation, linking it to the formation of brown dwarfs and low-mass stars, and explains related observational phenomena.

Findings

Disc fragmentation can account for the low-mass initial mass function.

The model explains the brown dwarf desert and binary properties.

Disc fragmentation is a short-lived process, making observation unlikely.

Abstract

A large fraction of brown dwarfs and low-mass stars may form by gravitational fragmentation of relatively massive (a few 0.1 Msun), extended (a few hundred AU) discs around Sun-like stars. We present an ensemble of radiative hydrodynamic simulations that examine the conditions for disc fragmentation. We demonstrate that this model can explain the low-mass IMF, the brown dwarf desert, and the binary properties of low-mass stars and brown dwarfs. Observing discs that are undergoing fragmentation is possible but very improbable, as the process of disc fragmentation is short lived (discs fragment within a few thousand years).