On the density distribution in star-forming interstellar clouds

Abstract

We use deep adaptive mesh refinement simulations of isothermal self-gravitating supersonic turbulence to study the imprints of gravity on the mass density distribution in molecular clouds. The simulations show that the density distribution in self-gravitating clouds develops an extended power-law tail at high densities on top of the usual lognormal. We associate the origin of the tail with self-similar collapse solutions and predict the power index values in the range from-7/4 to-3/2 that agree with both simulations and observations of star-forming molecular clouds. © 2011. The American Astronomical Society. All rights reserved. Printedin the U.S.A.