Description
We numerically study the volume density probability density function (n-PDF) and the column density probability density function (\sigma-PDF) resulting from thermally bistable turbulent flows with and without self-gravity. For this aim we analyze three- dimensional hydrodynamic models in periodic boxes of 100pc by side with forced turbulence at large scales and different Mach numbers (M). At low densities (n~<0.6 cm^-3), the n-PDF is well described by a lognormal distribution, but as consequence of the nonlinear development of thermal instability (TI), the logarithmic variance of the distribution increases faster with M than it does in the isothermal case. For the dense gas (n~>7.1 cm^-3) the shape of the PDF depends on the Mach number and change in the presence of self-gravity in low M models. On the other hand, for non self gravitating models, \sigma-PDF at high column densities is well described by a lognormal for all the values of M and, due to the presence of TI, the width of the distribution is systematically larger than in the isothermal case but follows a similar behavior as M increases. When gravity is included, the shape of the \sigma-PDF at high column densities depends on the value of M.
Author
Adriana Gazol
(CRyA,UNAM)