The width of Herschel filaments varies with distance
Journal article, 2022

Context. Filamentary structures in nearby molecular clouds have been found to exhibit a characteristic width of 0.1 pc, as observed in dust emission. Understanding the origin of this universal width has become a topic of central importance in the study of molecular cloud structure and the early stages of star formation.
Aims. We investigate how the recovered widths of filaments depend on the distance from the observer by using previously published results from the Herschel Gould Belt Survey. Methods. We obtained updated estimates on the distances to nearby molecular clouds observed with Herschel by using recent results based on 3D dust extinction mapping and Gaia. We examined the widths of filaments from individual clouds separately, as opposed to treating them as a single population. We used these per-cloud filament widths to search for signs of variation amongst the clouds of the previously published study.
Results. We find a significant dependence of the mean per-cloud filament width with distance. The distribution of mean filament widths for nearby clouds is incompatible with that of farther away clouds. The mean per-cloud widths scale with distance approximately as 4-5 times the beam size. We examine the effects of resolution by performing a convergence study of a filament profile in the Herschel image of the Taurus Molecular Cloud. We find that resolution can severely affect the shapes of radial profiles over the observed range of distances.
Conclusions. We conclude that the data are inconsistent with 0.1 pc being the universal characteristic width of filaments.

Stars: formation

ISM: structure

ISM: clouds

Local insterstellar matter

Author

G. V. Panopoulou

California Institute of Technology (Caltech)

S. E. Clark

Stanford University

A. Hacar

University of Vienna

F. Heitsch

The University of North Carolina System

Jouni Kainulainen

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

E. Ntormousi

Scuola Normale Superiore di Pisa

D. Seifried

University of Cologne

R. J. Smith

University of Manchester

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 657 L13

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.1051/0004-6361/202142281

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3/6/2024 1