Abstract
We formulate the problem of the formation of magnetically supercritical cores in magnetically subcritical parent molecular clouds, and the subsequent collapse of the cores to high densities, past the detachment of ions from magnetic field lines and into the opaque regime. We employ the six-fluid MHD equations, accounting for the effects of grains (negative, positive, and neutral) including their inelastic collisions with other species. We do not assume that the magnetic flux is frozen in any of the charged species. We derive a generalized Ohm's law that explicitly distinguishes between flux advection (and the associated process of ambipolar diffusion) and Ohmic dissipation, in order to assess the contribution of each mechanism to the increase of the mass-to-flux ratio of the central parts of a collapsing core and possibly to the resolution of the magnetic flux problem of star formation. The results, including a detailed parameter study, are presented in two accompanying papers.
Original language | English (US) |
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Pages (from-to) | 370-387 |
Number of pages | 18 |
Journal | Astrophysical Journal |
Volume | 660 |
Issue number | 1 I |
DOIs | |
State | Published - May 1 2007 |
Keywords
- Dust, extinction
- ISM: clouds
- MHD
- Magnetic fields
- Shock waves
- Stars: formation
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science