Realism of Increasing the Turbulent Driving Parameter b Without Feedback

Determine whether it is realistic for the turbulent driving parameter b in the log-normal density probability distribution used by turbulence-regulated star formation models to increase in the absence of stellar feedback sufficiently to reproduce the observed surge in star formation efficiency within molecular clouds.

Background

The authors evaluate turbulence-regulated models that rely on a log-normal density distribution with a driving parameter b. To match the observed order-of-magnitude increase in star formation efficiency when feedback is halted, b would need to be higher in the no-feedback case than in the feedback case.

They find little difference in b between stacked cloud populations with and without feedback and question the realism of the required b increase, noting mixed evidence from previous studies on how feedback drives compressive vs. solenoidal turbulence.