| Abstrakt: |
Filamentary structures identified in far-infrared observations of molecular clouds are typically found to have full widths at half-maximum |$\sim 0.1\, {\rm pc}$|. However, the physical explanation for this phenomenon is currently uncertain. We use hydrodynamic simulations of cylindrically symmetric converging flows to show that the full width at half-maximum of the resulting filament's surface density profile, |$\rm{\small FWHM}{_\Sigma }$| , is closely related to the location of the accretion shock, where the inflow meets the boundary of the filament. For inflow Mach number, |${\cal M}$| , between 1 and 5, filament |$\rm{\small FWHM}{_\Sigma }$| s fall in the range |$0.03\, {\rm pc}\lesssim \rm{\small FWHM}{_\Sigma }\lesssim 0.3\, {\rm pc}$| , with higher |${\cal M}$| resulting in narrower filaments. A large sample of filaments, seen at different evolutionary stages and with different values of |${\cal M}$| , naturally results in a peaked distribution of |$\rm{\small FWHM}{_\Sigma }$| s similar in shape to that obtained from far-infrared observations of molecular clouds. However, unless the converging flows are limited to |${\cal M} \lesssim 3$| , the peak of the distribution of |$\rm{\small FWHM}{_\Sigma }$| s is below the observed |$\sim 0.1 \, {\rm pc}$|. [ABSTRACT FROM AUTHOR] |
