Simulation of the gravitational collapse and fragmentation of rotating molecular clouds

Abstract

In this paper we study the process of the subsequent (runaway) fragmentation of a rotating isothermal Giant Molecular Cloud (GMC) complex. Our own Smoothed Particle Hydrodynamics (SPH) gas-dynamical model successfully reproduces the observed Cloud Mass-distribution Function (CMF) in our Galaxy (even the differences between the inner and outer parts of our Galaxy). The steady state of CMF is established during the collapse within a free-fall timescale of the GMC. We show that one of the key parameters, which defines the observed slope of the present day CMF, is the initial ratio of the rotational (turbulent) and gravitational energy inside the fragmented GMC.