Ambipolar diffusion in self-gravitating filaments

Abstract

Abstract. One-dimensional similarity solutions for a collapsing, homogeneous, infinitely long cylinder that is subject to ambipolar diffusion are given. There is an analytical solution with infinite density being reached after 4.3 free-fall times. In that case the magnetic field strength B z on the axis scales like B z ∝ ρ 2/3 with density ρ. The analytical solution proves "attractive". Even if the initial conditions depart slightly from those of the analytical solution, that solution is nevertheless approached through damped oscillations.