The Effects of Protostellar Jet Feedback on Turbulent Collapse

TL;DR

Hydrodynamic simulations reveal that protostellar jets modestly influence star formation rates and turbulence, primarily affecting small-scale structures and accretion efficiencies without significantly altering overall star formation dynamics.

Contribution

This study provides the first detailed hydrodynamic simulation comparison of star formation with and without protostellar jets, highlighting their limited impact on large-scale dynamics.

Findings

Jets slightly reduce accretion rates onto protostars.

Small-scale structures are similar regardless of jet presence.

Jets induce turbulence mainly on parsec scales.

Abstract

We present results of hydrodynamic simulations of massive star forming regions with and without protostellar jets. We show that jets change the normalization of the stellar mass accretion rate, but do not strongly affect the dynamics of star formation. In particular, $M_*(t) \propto f^2 (t-t_*)^2$ where $f = 1 - f_{\rm jet}$ is the fraction of mass accreted onto the protostar, $f_{\rm jet}$ is the fraction ejected by the jet, and $(t-t_*)^2$ is the time elapsed since the formation of the first star. The star formation efficiency is nonlinear in time. We find that jets have only a small effect (of order 25\%) on the accretion rate onto the protostellar disk (the "raw" accretion rate). We show that the small scale structure -- the radial density, velocity, and mass accretion profiles are very similar in the jet and no-jet cases. Finally, we show that the inclusion of jets does drive turbulence but only on small (parsec) scales.