A closer look at the "characteristic" width of molecular cloud filaments
  Filaments in Herschel molecular cloud images are found to exhibit a
"characteristic width". This finding is in tension with spatial power spectra
of the data, which show no indication of this characteristic scale. We
demonstrate that this discrepancy is a result of the methodology adopted for
measuring filament widths. First, we perform the previously used analysis
technique on artificial scale-free data, and obtain a peaked width distribution
of filament-like structures. Next, we repeat the analysis on three Herschel
maps and reproduce the narrow distribution of widths found in previous studies
$-$ when considering the average width of each filament. However, the
distribution of widths measured at all points along a filament spine is broader
than the distribution of mean filament widths, indicating that the narrow
spread (interpreted as a "characteristic" width) results from averaging.
Furthermore, the width is found to vary significantly from one end of a
filament to the other. Therefore, the previously identified peak at 0.1 pc
cannot be understood as representing the typical width of filaments. We find an
alternative explanation by modelling the observed width distribution as a
truncated power-law distribution, sampled with uncertainties. The position of
the peak is connected to the lower truncation scale and is likely set by the
choice of parameters used in measuring filament widths. We conclude that a
"characteristic" width of filaments is not supported by the available data.
