Turbulence in the Ursa Major cirrus cloud

High resolution 21 cm observations of the Ursa Major cirrus revealed highly filamentary structures down to the 0.03 pc resolution. These filaments, still present in the line centroid map, show multi-Gaussian components and seem to be associated with high vorticity regions. Probability density functions of line centroid increments and structure functions were computed on the line centroid field, providing strong evidences for the presence of turbulence in the atomic gas.