Observations of translucent molecular gas in 12CO and 13CO emission lines, at high spectral and spatial resolutions, evidence different kinds of structures at small scales: (1) optically thin 12CO emission, (2) optically thick 12CO emission, visible in 13CO(1-0), and (3) regions of largest velocity shear in the field, found from a statistical analysis. They are all elongated with high aspect ratio, preferentially aligned with the plane-of-the-sky projection of the magnetic fields. The latter structures coincide with the former, shown to trace gas warmer and more diluted than average. Combining our data to large-scale observations of poorer spatial resolution, we show that the regions of largest velocity shear remain coherent over more than a parsec. These filaments are proposed to be the sites of the intermittent dissipation of turbulence.
@article{arxiv.astro-ph/0701326,
title = {Small-scale dissipative structures of diffuse ISM turbulence: I- CO diagnostics},
author = {Pierre Hily-Blant and Jerome Pety and Edith Falgarone},
journal= {arXiv preprint arXiv:astro-ph/0701326},
year = {2007}
}