Serpens filament emission lines datacubes

The inner radial column density profile of this filament can be well fitted with a Plummer profile with an exponent of 2.2+/-0.1, a scale radius of 0.018+/-0.003pc and a central density of (4.0+/-0.8)x10^4^cm^-3^. The Serpens filament appears to be slightly supercritical. The widespread blue-skewed HNC and CS line profiles and HCN hyperfine line anomalies across this filament indicate radial infall in parts of the Serpens filament.

C^18^O velocity gradients also indicate accretion flows along the filament. The velocity and density structures suggest that such accretion flows are likely due to a longitudinal collapse parallel to the filament's long axis. Both the radial infall rate and the longitudinal accretion rate along the Serpens filament are lower than all previously reported values in other filaments.

This indicates that the Serpens filament lies at an early evolutionary stage when collapse has just begun, or that thermal and non-thermal support are effective in providing support against gravity.