Supersonic turbulence in the cold massive core JCMT 18354-0649S

TL;DR

This study examines a cold massive core, JCMT 18354-0649S, revealing it as a scaled-up low mass star-forming core with significantly higher turbulence and infall velocities, suggesting turbulence dissipation leads to dense gas clumps.

Contribution

It provides detailed modeling of a high mass core showing how turbulence and infall velocities scale from low to high mass cores, highlighting turbulence dissipation effects.

Findings

JCMT 18354-0649S has higher turbulence and infall velocities than typical low mass cores.

The core's properties are similar to low mass cores but scaled up in mass and turbulence.

Dissipation of supersonic turbulence may create dense gas clumps around the core.

Abstract

An example of a cold massive core, JCMT 18354-0649S, a possible high mass analogue to a low mass star forming core is studied. Line and continuum observations from JCMT, Mopra Telescope and Spitzer are presented and modelled in detail using a 3D molecular line radiative transfer code. In almost every way JCMT 18354-0649S is a scaled-up version of a typical low mass core with similar temperatures, chemical abundances and densities. The difference is that both the infall velocity and the turbulent width of the line profiles are an order of magnitude larger. While the higher infall velocity is expected due to the large mass of JCMT 18354-0649S, we suggest that the dissipation of this highly supersonic turbulence may lead to the creation of dense clumps of gas that surround the high mass core.