| This dissertation is composed of three parts: In part I, we idealize giant molecular clouds as flattened sheets, incorporating the concepts of strong magnetization, star formation from dense cores, and efficient bipolar outflows. This toy model reproduces the observed tendency of molecular clouds to form filaments without the need to invoke large-scale overall gravitational collapse that would yield a rate of star formation far in excess of empirical Galactic values. It yields linewidth-size relationships that are in rough accord with observations, although better simulations are needed that remove the imposition of periodic boundary conditions and allow for a more systematic treatment of subgrid turbulence. The model lends credence to earlier ideas concerning the self-regulation of star formation by turbulence and photo-ionization. Part II studies the collapse of molecular clouds on to binary gravitational sources. We have calculated stable disk geometries in a binary system. Infall from a slowly rotating, isothermal cloud is simulated by following test particle trajectories. From this, velocity and density fields of the infall were found that indicate infall signatures will be hard to observe past the orbital separation of the system, as well as the tendency for the smaller binary source to get slightly more than it's fair share of mass, and for sufficiently lopsided binaries, the tendency for the smaller star's disk to be retrograde. Part III generalizes the self-similar collapse solution of the (unmagnetized) singular isothermal sphere to magnetized singular isothermal torroids. The pre-collapse initial states flatten with increasing magnetic support. The collapse solution is flattened as well, showing magnetically supported thin disks of high density in the equatorial plane. The central mass accretion rate is found to be constant, in agreement with theory. |
