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

An example of a cold massive core, JCMT 18354-0649S which is a possible high-mass analogue to a low-mass star-forming core, is studied. Line and continuum observations from James Clerk Maxwell Telescope, 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.