Characterizing interstellar filaments with Herschel in IC5146

Source: arXiv


We provide a first look at the results of the Herschel Gould Belt survey
toward the IC5146 molecular cloud and present a preliminary analysis of the
filamentary structure in this region. The column density map, derived from our
70-500 micron Herschel data, reveals a complex network of filaments, and
confirms that these filaments are the main birth sites of prestellar cores. We
analyze the column density profiles of 27 filaments and show that the
underlying radial density profiles fall off as r^{-1.5} to r^{-2.5} at large
radii. Our main result is that the filaments seem to be characterized by a
narrow distribution of widths having a median value of 0.10 +- 0.03 pc, which
is in stark contrast to a much broader distribution of central Jeans lengths.
This characteristic width of ~0.1 pc corresponds to within a factor of ~2 to
the sonic scale below which interstellar turbulence becomes subsonic in diffuse
gas, supporting the argument that the filaments may form as a result of the
dissipation of large-scale turbulence.

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Available from: Glenn J. White, Oct 02, 2015
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