EPoS Contribution
EPoS Contribution
The Properties of Nearby Molecular Filaments as Derived from Herschel Gould Belt Survey Observations

Philippe Andre
CEA-Lab AIM, Paris-Saclay, FR
Herschel imaging surveys of Galactic molecular clouds have emphasized the quasi-universality of the filamentary structure of the cold ISM and the key role of filaments in the star formation process. I will first summarize the findings of a systematic census of filamentary structures in nearby molecular clouds, comprising more than 500 filaments in 8 regions covered by the Herschel Gould Belt survey. I will then discuss the implications of the results for our understanding of filament evolution and star formation along filaments. Overall, our observations support a picture in which molecular filaments and prestellar cores represent two fundamental steps in the star formation process: First, large-scale compression of interstellar material in supersonic MHD flows generates a cobweb of filaments of ~ 0.1 pc width in the cold ISM; second, the densest filaments fragment into prestellar cores (and subsequently protostars) by gravitational instability, while simultaneously growing in mass and complexity through accretion of background cloud material.
Caption: a) Plot of mass per unit length vs. central column density for a sample of 524 filaments in 8 regions covered by the Herschel Gould Belt survey. The best-fit linear correlation suggests an effective filament width ~ 0.13 pc on average in the sample. b) Example column density map of a system of 3 filaments imaged with Herschel in the Orion B cloud. c) Radial column density profile of filament # 1 in panel b). Fitting the observed profile yields an inner width of 0.07-0.09 pc. The mass per unit length shown on the y-axis of panel a) was obtained by integrating the column density profile over radius. (Figure adapted from Arzoumanian, Andre et al. 2018, submitted.)
Collaborators:
D. Arzoumanian, Nagoya U, JP
and the Herschel Gould Belt survey team
Key publication

Suggested Session: Filaments