SIMBAD references

2012ApJ...759L..27P - Astrophys. J., 759, L27 (2012/November-2)

A simple law of star formation.


Abstract (from CDS):

We show that supersonic MHD turbulence yields a star formation rate (SFR) as low as observed in molecular clouds, for characteristic values of the free-fall time divided by the dynamical time, tff/tdyn, the Alfvénic Mach number, Ma, and the sonic Mach number, Ms. Using a very large set of deep adaptive-mesh-refinement simulations, we quantify the dependence of the SFR per free-fall time, εff, on the above parameters. Our main results are (1) that εff decreases exponentially with increasing tff/tdyn, but is insensitive to changes in Ms, for constant values of tff/tdyn and Ma. (2) Decreasing values of Ma (stronger magnetic fields) reduce εff, but only to a point, beyond which εff increases with a further decrease of Ma. (3) For values of Ma characteristic of star-forming regions, εff varies with Ma by less than a factor of two. We propose a simple star formation law, based on the empirical fit to the minimum εff, and depending only on tff/tdyn: εff ~ εwind exp (- 1.6 tff/tdyn). Because it only depends on the mean gas density and rms velocity, this law is straightforward to implement in simulations and analytical models of galaxy formation and evolution.

Abstract Copyright:

Journal keyword(s): ISM: kinematics and dynamics - magnetohydrodynamics, MHD - stars: formation - turbulence

Simbad objects: 1

goto Full paper

goto View the reference in ADS

To bookmark this query, right click on this link: simbad:2012ApJ...759L..27P and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact