Abstract
Under ideal MHD conditions the magnetic field strength should be correlated with density in the interstellar medium (ISM). However, observations indicate that this correlation is weaker than expected. Ambipolar diffusion can decrease the flux-to-mass ratio in weakly ionized media; however, it is generally thought to be too slow to play a significant role in the ISM except in the densest molecular clouds. Turbulence is often invoked in other astrophysical problems to increase transport rates above the (very slow) diffusive values. Building on analytical studies, we test with numerical models whether turbulence can enhance the ambipolar diffusion rate sufficiently to explain the observed weak correlations. The numerical method is based on a gas-kinetic scheme with very low numerical diffusivity, thus allowing us to separate numerical and physical diffusion effects.
Similar content being viewed by others
References
Ballesteros-Paredes, J., Vázquez-Semadeni, E. and Scalo, J.: 1999, ApJ 515, 286.
Bourke, T.L., Myers, P.C., Robinson, G. and Hyland, A.R.: 2001, ApJ 554, 916.
Brandenburg, A. and Zweibel, E.G.: 1994, ApJL 427, 91.
Crutcher, R.M.: 1999, ApJ 520, 706.
Fatuzzo, M. and Adams, F.C.: 2002, ApJ 570, 210.
Fiedler, R.A. and Mouschovias, T.Ch.: 1993, ApJ 415, 680.
Galloway, D.J. and Proctor, M.R.E.: 1992, Nature 356, 691.
Heiles, C.: 2003, Observations of Turbulence in the Diffuse ISM, Proceedings of the Workshop: Magnetic Fields and Star Formation: Theory Versus Observations,Kluwer.
Heitsch, F. and Zweibel, E.G.: 2003, ApJ 583, 229.
Heitsch, F., Zweibel, E.G., Slyz, A.D. and Devriendt, J.E.G.: 2003, in preparation.
Kim, E.-J. and Diamond, P.H.: 2002, ApJ 578, 113.
Lazarian, A. and Vishniac, E.T.: 1999, ApJ 517, 700.
Mac Low, M.-M. and Smith, M.D.: 1997, ApJ 491, 596.
Mestel, L.: 1985, in: D.C. Black and M.S. (eds.), Protostars and Planes II, Matthews Tucson: Univ. Arizona Press, 320.
Petschek, A.G.: 1969, in: W.N. Hess (ed.), AAS-NASA Symp. on the Physics of Solar Flares,NASA SP-50, Greenbelt: NASA, p. 425.
Tang, H.Z. and Xu, K.: 2000, J. Comp. Phys. 165, 69.
Troland, T.H. and Heiles, C.: 1986, ApJ 339, 345.
Xu, K.: 1999, J. Comp. Phys. 153, 334.
Zweibel, E.G.: 2002, ApJ 567, 962.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Heitsch, F., Zweibel, E.G., Slyz, A.D. et al. Magnetic Flux Transport in the ISM Through Turbulent Ambipolar Diffusion. Astrophysics and Space Science 292, 45–51 (2004). https://doi.org/10.1023/B:ASTR.0000044999.25908.a5
Issue Date:
DOI: https://doi.org/10.1023/B:ASTR.0000044999.25908.a5