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Other Publications Year : 2021

Density structure and fragmentation manner of infrared dark filaments


The results of Herschel and Spitzer imaging surveys of nearby Galactic clouds suggest that most stars form in dense molecular filaments, which are often dark at near- to mid-IR wavelengths. The Herschel results support a filament paradigm for at least solar-type star formation, whereby Jeans-like fragmentation of 0.1-pc-wide supercritical filaments produces < 0.1pc prestellar cores, which subsequently collapse to protostars. The validity and details of this paradigm are much debated, however, and the detailed fragmentation manner of filaments remains a puzzle. Despite ongoing debates, the properties of dense filaments are thought to be representative of the initial conditions of most star formation in the Galaxy. We propose to exploit the unique resolution and sensitivity of JWST in the mid-IR to determine the radial density structure and fragmentation spacing properties of a sample of 6 infrared-dark filaments at different locations in the Galactic disk with unprecedented accuracy. The proposed observations will resolve the thermal Jeans length < 0.02 pc, provide a deep census of starless dense cores down to the Jeans mass, and determine the core mass function in each filament. The results will be compared with numerical simulations of filament fragmentation. They will be used to test the simple picture, tentatively suggested by recent ALMA findings, that the average filament width and core spacing remain roughly the same in all filaments, but that the typical core mass scales ~ linearly with the line mass of the parent filament. If confirmed by the proposed MIRI study, this will have profound implications for our understanding of the origin of the initial mass function.
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hal-03561797 , version 1 (08-02-2022)


  • HAL Id : hal-03561797 , version 1


Philippe André, Michael Mattern, Delphine Russeil, Yoshito Shimajiri, Annie Zavagno. Density structure and fragmentation manner of infrared dark filaments. 2021. ⟨hal-03561797⟩
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