大样本恒星演化研究组知识库

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 beta(n), the turbulence driving parameter, i.e. the b parameter and the 1D Fourier velocity power spectral index beta(upsilon). Then I calculate the line profiles of (CO)-C-13 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 beta(n) increases, (1) the standard deviations sigma(ln(N/< N >)) and sigma(ln(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 sigma(ln(N/< N >)) and sigma(ln(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 beta(upsilon) 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 sigma(N/< N)> Mach number, the b parameter and beta(n).