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Mouschovias, T. Ch. Morton, Scott Allyn 2011-04-27T15:47:50Z 2011-04-27T15:47:50Z 10000-01-01 1991 The formation of stars is a fundamental unsolved problem in astrophysics. Interstellar molecular clouds, observed to be the birth place of stars, have masses much larger than those of typical stars. Observed densities, temperatures, and strengths of well-ordered magnetic fields imply that magnetic forces, transmitted to the neutral fluid through collisions with ions, dominate thermal forces in supporting these objects against self-gravity. The anisotropy of the Lorentz force, which is always perpendicular to the magnetic field, allows a simplified treatment of the dynamics involving motion along the magnetic field. We derive a reduced system of non-linear, non-ideal magnetohydrodynamic equations by assuming a balance of thermal and gravitational forces along the magnetic field. We then study both the stability of dense clouds as well as their non-linear evolution/ contraction owing to ambipolar diffusion. An important result is the selection by ambipolar diffusion of a characteristic mass comparable to a solar mass. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-04-27T15:47:50Z No. of bitstreams: 1 1991_morton.pdf: 9447337 bytes, checksum: 4c99ad0be444ed07f3dc737a8cd76966 (MD5) Made available in DSpace on 2011-04-27T15:47:50Z (GMT). No. of bitstreams: 1 1991_morton.pdf: 9447337 bytes, checksum: 4c99ad0be444ed07f3dc737a8cd76966 (MD5) Previous issue date: 1991 Restriction data tranferred 2014-07-01T11:12:17-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-04-27T15:47:50Z Item is restricted indefinitely. Thesis U of I Only 3471936 http://hdl.handle.net/2142/18891 en 1991 Scott Allyn Morton ambipolar diffusion interstellar cloud cores protostars formation of stars astrophysics The role of ambipolar diffusion in the formation of interstellar cloud cores and protostars Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.