Structure Function Scaling in Compressible Super-Alfvénic MHD Turbulence
Abstract
Supersonic turbulent flows of magnetized gas are believed to play an important role in the dynamics of star-forming clouds in galaxies. Understanding statistical properties of such flows is crucial for developing a theory of star formation. In this Letter we propose a unified approach for obtaining the velocity scaling in compressible and super-Alfvénic turbulence, valid for the arbitrary sonic Mach number, MS. We demonstrate with numerical simulations that the scaling can be described with the She-Lévêque formalism, where only one parameter, interpreted as the Hausdorff dimension of the most intense dissipative structures, needs to be varied as a function of MS. Our results thus provide a method for obtaining the velocity scaling in interstellar clouds once their Mach numbers have been inferred from observations.
- Publication:
-
Physical Review Letters
- Pub Date:
- May 2004
- DOI:
- 10.1103/PhysRevLett.92.191102
- arXiv:
- arXiv:astro-ph/0301026
- Bibcode:
- 2004PhRvL..92s1102P
- Keywords:
-
- 95.30.Qd;
- 52.30.Cv;
- 52.35.Ra;
- 98.38.Am;
- Magnetohydrodynamics and plasmas;
- Magnetohydrodynamics;
- Plasma turbulence;
- Physical properties;
- Astrophysics;
- Nonlinear Sciences - Chaotic Dynamics;
- Physics - Fluid Dynamics
- E-Print:
- published in Physical Review Letters