Protostar Formation in Magnetic Molecular Clouds beyond Ion Detachment: III. A Parameter Study

Details Protostar Formation in Magnetic Molecular Clouds beyond Ion Detachment: III. A Parameter Study Protostar Formation in Magnetic Molecular Clouds beyond Ion Detachment: III. A Parameter Study

2007-02-01

arxiv.org/abs/astro-ph/0702038v1

Astrophys.J.660:402-417,2007

Astronomy and Astrophysics

Astrophysics

17 pages, 14 figures, emulateapj; accepted for publication in the Astrophysical Journal

Scientific paper

10.1086/512762

In two previous papers we formulated and solved, for a fiducial set of free parameters, the problem of the formation and evolution of a magnetically supercritical core inside a magnetically subcritical parent cloud. In this paper we present a parameter study to assess the sensitivity of the results (1) to the density at which the equation of state becomes adiabatic; (2) to the initial mass-to-flux ratio of the parent cloud; and (3) to ionization by radioactive decay of different nuclei (40K and 26Al) at high densities (number density > 10^12 particles per cubic cm). We find that (1) the results depend only slightly on the density at which the onset of adiabaticity occurs; (2) memory of the initial mass-to-flux ratio is completely lost at late times, which emphasizes the relevance of this work, idependently of the adopted theory of core formation; and (3) the precise source of radioactive ionization alters the degree of attachment of the electrons to the field lines (at high densities), and the relative importance of ambipolar diffusion and Ohmic dissipation in reducing the magnetic flux of the protostar. The value of the magnetic field at the end of the runs is insensitive to the values of the free parameters and in excellent agreement with meteoritic measurements of the protosolar nebula magnetic field. The magnetic flux problem of star formation is resolved for at least strongly magnetic newborn stars. A complete detachment of the magnetic field from the matter is unlikely. The formation of a "magnetic wall" (with an associated magnetic shock) is independent of the assumed equation of state, although the process is enhanced and accelerated by the formation of a central hydrostatic core.

Affiliated with

Also associated with

No associations

Rating

Protostar Formation in Magnetic Molecular Clouds beyond Ion Detachment: III. A Parameter Study does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Protostar Formation in Magnetic Molecular Clouds beyond Ion Detachment: III. A Parameter Study, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Protostar Formation in Magnetic Molecular Clouds beyond Ion Detachment: III. A Parameter Study will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-675512