Interstellar turbulent velocity fields: Scaling properties, synthesis and effects on chemistry^*

LUTH, Observatoire de Paris et Université Paris 7, France

Corresponding author: J. Le Bourlot, Jacques.lebourlot@obspm.fr

Received: 26 November 2001
Accepted: 3 April 2002

Abstract

Turbulence is thought to play a key role in the dynamics of interstellar clouds. Here, we do not seek to explain its origin or decipher the mechanisms that maintain it, but we start from the observational fact that it is present. Arnéodo et al. have developped a method based on wavelet analysis to study incompressible turbulence experiments. We propose to use this method with the same propagator to derive quantitative information on the structure of a turbulent field. Then we build a synthetic velocity field with the same statistical properties and we show that a reactive fluid subject to turbulent forcing exhibits self-organised structures that depend on the chemical species considered. Such effects could explain why observational evidence shows that the bulk of the mass is distributed smoothly whereas some chemical species are extremely patchy.