Star formation in molecular cores III. The effect of the turbulent power spectrum

TL;DR

This study uses SPH simulations to explore how different turbulent power spectra influence the fragmentation of low-mass molecular cores, revealing that larger-scale turbulence leads to more protostars and a higher fraction of low-mass objects.

Contribution

It demonstrates the impact of the turbulent power spectrum slope on star formation outcomes, contrasting with previous studies that used higher turbulence levels.

Findings

Larger n-values produce more protostellar objects.

Higher n-values result in a greater proportion of low-mass stars and brown dwarfs.

Results differ from prior work due to variations in turbulence levels.

Abstract

We investigate the effect of the turbulent power spectrum (P(k) \propto k^{-n}, with n=3, 4 or 5) on the fragmentation of low-mass cores, by means of SPH simulations. We adopt initial density profiles and low levels of turbulence based on observation, and for each n-value we conduct an ensemble of simulations with different initial seeds for the turbulent velocity field, so as to obtain reasonable statistics. We find that when power is concentrated at larger scales (i.e. for larger n), more protostellar objects form and there is a higher proportion of low-mass stars and brown dwarfs. This is in direct contrast with the recent results of Delgado Donate et al., presumably because they adopted much higher levels of turbulence.