1999/06/21 by Mordecai-Mark Mac Low, Mordecai‐Mark Mac Low, Mac Low, Mordecai-Mark +3
Mathematics · Physics and Astronomy · #Astrophysics #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #Classical mechanics #Computational physics #Dissipation #FOS: Physical sciences #Ionosphere and magnetosphere dynamics #Kinetic energy #Mach number #Magnetic field #Magnetohydrodynamics #Mathematics #Mechanics #Physics #Power law #Scale (ratio) #Solar and Space Plasma Dynamics #Statistical physics #Statistics #Supersonic speed #Thermodynamics #Turbulence #Turbulence kinetic energy #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9906334
11 pages, 10 figures, submitted to Astronomy & Astrophysics
arxiv created 1999/06/21 · openalex publication_date 1999/06/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Modeling the structure of molecular clouds depends on good methods to statistically compare simulations with observations in order to constrain the models. Here we characterize a suite of hydrodynamical and magnetohydrodynamical (MHD) simulations of supersonic turbulence using an averaged wavelet transform, the Delta-variance, that has been successfully used to characterize observations. We find that, independent of numerical resolution and dissipation, the only models that produce scale-free, power-law Delta-variance spectra are those with hypersonic Mach numbers above M ~ 4, while slower supersonic turbulence tends to show characteristic scales and produce non-power-law spectra. Magnetic fields have only a minor influence on this tendency, though they tend to reduce the scale-free nature of the turbulence, and increase the transfer of energy from large to small scales. The evolution of the characteristic length scale seen in supersonic turbulence follows exactly the t1/2 power-law predicted from recent studies of the kinetic energy decay rate.