McLeman, J. A. and Wang, C. H. -T. and Bingham, R. (2012) Gravitational stability of a cylindrical plasma with an azimuthal and an axial magnetic field. Astrophysical Journal, 756 (2). ISSN 0004-637XFull text not available in this repository. (Request a copy from the Strathclyde author)
We consider the gravitational stability of a current-carrying filamentary cloud in the presence of both axial and azimuthal magnetic fields using a simple analytic model. The azimuthal magnetic field is shown to give rise to a new contribution, dictated by Ampere's law, in the corresponding virial equation for magnetohydrodynamic equilibrium. From this we obtain a computationally inexpensive guidance on the gravitational stability of current-carrying filamentary clouds. The approach not only provides a fresh insight into the essential physical mechanisms involved but also demonstrates clearly that, for sufficiently large and yet astronomically realistic currents, the azimuthal magnetic field can cause filamentary clouds to undergo instability.
|Keywords:||magnetic fields, star formation, plasma, Physics, Astronomy and Astrophysics, Space and Planetary Science|
|Subjects:||Science > Physics|
|Department:||Faculty of Science > Physics|
|Depositing user:||Pure Administrator|
|Date Deposited:||04 Dec 2012 16:58|
|Last modified:||27 Apr 2016 19:22|