title: Compressible sub-Alfvénic MHD turbulence in low-beta plasmas.
abstract: We present a model for compressible sub-Alfvénic isothermal magnetohydrodynamic (MHD) turbulence in low- beta plasmas and numerically test it. We separate MHD fluctuations into three distinct families: Alfvén, slow, and fast modes. We find that production of slow and fast modes by Alfvénic turbulence is suppressed. As a result, Alfvén modes in compressible regime exhibit scalings and anisotropy similar to those in incompressible regime. Slow modes passively mimic Alfvén modes. However, fast modes show isotropy and a scaling similar to acoustic turbulence.
authors.affiliation: Astronomy Department, University of Wisconsin, Madison, WI 53706, USA. cho@astro.wisc.edu
authors.forename: Jungyeon
authors.initials: J
authors.lastname: Cho
authors.forename: A
authors.initials: A
authors.lastname: Lazarian