  The local well-posedness and low Mach number limit are considered for the
multi-dimensional isentropic compressible viscous magnetohydrodynamic equations
in critical spaces. First the local well-posedness of solution to the viscous
magnetohydrodynamic equations with large initial data is established. Then the
low Mach number limit is studied for general large data and it is proved that
the solution of the compressible magnetohydrodynamic equations converges to
that of the incompressible magnetohydrodynamic equations as the Mach number
tends to zero. Moreover, the convergence rates are obtained.
