The effects of the variations of turbulence parameters on the observable turbulence statistics

In order to study how the statistical properties of the observational quantities of the turbulent molecular cloud models vary with different turbulence parameters, I use the artificially generated random numerical models based on Gaussian fields created by the code pyfc with different values of the...

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Veröffentlicht in:Monthly notices of the Royal Astronomical Society 2016-06, Vol.458 (4), p.3489-3505
1. Verfasser: Ding, S. Y.
Format: Artikel
Sprache:eng
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Zusammenfassung:In order to study how the statistical properties of the observational quantities of the turbulent molecular cloud models vary with different turbulence parameters, I use the artificially generated random numerical models based on Gaussian fields created by the code pyfc with different values of the 1D density Fourier spectral index β n , the turbulence driving parameter, i.e. the b parameter and the 1D Fourier velocity power spectral index β v . Then I calculate the line profiles of 13CO emission on every sight line. I derive the statistical properties of column density N, line intensity W, peak intensity T peak and velocity dispersion V rms on every sight line. I discover that as β n increases, (1) the standard deviations σln (N/〈N〉) and σln (W/〈W〉) of the logarithmic column density ln (N/〈N〉) and the logarithmic integrated intensity ln (W/〈W〉) increase; (2) the number of the low T peak values becomes larger; (3) the probability distribution function (PDF) of V rms inclines to left a little. As the b parameter increases, (1) the values of both σln (N/〈N〉) and σln (W/〈W〉) increase; (2) the numbers of both the low T peak values and the saturated T peak values become larger; (3) the PDF of V rms inclines to left obviously. As β v increases, (1) the PDF of ln (W/〈W〉) remains generally unchanged; (2) the PDF of T peak remains generally unchanged; (3) the PDF of V rms inclines to left obviously. I also discuss the relationship among σ N/〈N〉, Mach number, the b parameter and β n .
ISSN:0035-8711
1365-2966
DOI:10.1093/mnras/stw485