G. Kowal et al. 2007 ApJ 658 423 doi:10.1086/511515
G. Kowal1, A. Lazarian1 and A. Beresnyak1
Show affiliationsWe perform three-dimensional (3D) compressible MHD simulations over many dynamical times for an extended range of sonic and Alfvén Mach numbers and analyze the statistics of 3D density and 2D column density, which include probability distribution functions, spectra, skewness, kurtosis, She-Lévêque exponents, and genus. In order to establish the relation between the statistics of the observables, i.e., column densities, and the underlying 3D statistics of density, we analyze the effects of cloud boundaries. We define the parameter space for 3D measures to be recovered from column densities. In addition, we show that for subsonic turbulence the spectra of density fluctuations are consistent with k-7/3 in the case of a strong magnetic field and k-5/3 in the case of a weak magnetic field. For supersonic turbulence we confirm the earlier findings of the shallow spectra of density and Kolmogorov spectra of the logarithm of density. We find that the intermittencies of the density and velocity are very different.
Issue 1 (2007 March 20)
Received 2006 July 27, accepted for publication 2006 November 29
G. Kowal et al. 2007 ApJ 658 423
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