Molecular gas in high-mass filament WB673

TL;DR

This study investigates the dense gas distribution in the high-mass filament WB673, revealing its physical connection, mass distribution, and potential formation mechanisms through molecular line observations.

Contribution

It provides detailed molecular line observations of WB673, demonstrating the filament's physical connection and suggesting a formation scenario involving multiple compressions by supersonic waves.

Findings

The filament's total mass is approximately 10^4 solar masses.

Mass-to-length ratio of the filament is 360 M_sun/pc.

The PV-diagram shows a V-shaped velocity structure.

Abstract

We studied the distribution of dense gas in a filamentary molecular cloud containing several dense clumps. The center of the filament is given by the dense clump WB673. The clumps are high-mass and intermediate-mass star-forming regions. We observed CS(2-1), 13CO(1-0), C18O(1-0) and methanol lines at 96GHz toward WB673 with the Onsala Space Observatory 20-m telescope. We found CS(2-1) emission in the inter-clump medium so the clumps are physically connected and the whole cloud is indeed a filament. Its total mass is $10^4$ M$_{\odot}$ and mass-to-length ratio is 360 M$_{\odot}$pc$^{-1}$ from 13CO(1-0) data. Mass-to-length ratio for the dense gas is $3.4-34$ M$_{\odot}$pc$^{-1}$ from CS(2-1) data. The PV-diagram of the filament is V-shaped. We estimated physical conditions in the molecular gas using methanol lines. Location of the filament on the sky between extended shells suggests that it could be a good example to test theoretical models of formation of the filaments via multiple compression of interstellar gas by supersonic waves.