# Large-scale periodic velocity oscillation in the filamentary cloud G350.54+0.69

## TL;DR

This study reveals a large-scale periodic velocity oscillation in the filamentary cloud G350.54+0.69, likely driven by gravitational instability and MHD waves, providing insights into filament dynamics and core formation processes.

## Contribution

It is the first to identify and analyze a large-scale periodic velocity oscillation in a filamentary cloud, linking it to gravitational instability and MHD waves.

## Key findings

- Detected a ~1.3 pc wavelength velocity oscillation with ~0.12 km/s amplitude.
- Suggests the oscillation is driven by gravitational instability and MHD transverse waves.
- Provides a new perspective on filament dynamics and core formation mechanisms.

## Abstract

We use APEX mapping observations of 13CO, and C18O (2-1) to investigate the internal gas kinematics of the filamentary cloud G350.54+0.69, composed of the two distinct filaments G350.5-N and G350.5-S. G350.54+0.69 as a whole is supersonic and gravitationally bound. We find a large-scale periodic velocity oscillation along the entire G350.5-N filament with a wavelength of ~1.3 pc and an amplitude of ~0.12 km/s. Comparing with gravitational-instability induced core formation models, we conjecture that this periodic velocity oscillation could be driven by a combination of longitudinal gravitational instability and a large-scale periodic physical oscillation along the filament. The latter may be an example of an MHD transverse wave. This hypothesis can be tested with Zeeman and dust polarization measurements.