Title: Accretion driven turbulence in filaments I: Non-gravitational accretion,
Abstract: We study accretion driven turbulence for different inflow velocities in star
forming filaments using the code ramses. Filaments are rarely isolated objects
and their gravitational potential will lead to radially dominated accretion. In
the non-gravitational case, accretion by itself can already provoke
non-isotropic, radially dominated turbulent motions responsible for the complex
structure and non-thermal line widths observed in filaments. We find that there
is a direct linear relation between the absolute value of the total density
weighted velocity dispersion and the infall velocity. The turbulent velocity
dispersion in the filaments is independent of sound speed or any net flow along
the filament. We show that the density weighted velocity dispersion acts as an
additional pressure term supporting the filament in hydrostatic equilibrium.
Comparing to observations, we find that the projected non-thermal line width
variation is generally subsonic independent of inflow velocity.