by LI Juan
Thank to the newly built 9-pixel 3-mm heterodyne receivers of the PMO 14m telescope, a group of astronomers from Nanjing University (NJU) and Purple Mountain Observatory (PMO) studied the kinematic structure and magnetic fieldin dense molecular gas cores. The PMO 14m telescope in Delingha was used to observe the emission of molecules in molecular cores of high density in 27 Giant Molecular Clouds(GMCs) of our Milky Way.
In GMCs, newborn massive stars are hidden from visual respect, and the densegas clouds are still collapsing and forming more stars. Using multiple molecular gas tracers, which are excited in different physical conditions, evidence was found to support the chemical evolution of C2H molecule. It is for the first to support the "chemical clock" for C2H to diagnostic the life evolution and formation o massive stars.
From the moving information of the gas clouds, i.e. Dynamics, the energy transfer was studied. The energy from angular momentum to was found to be decreasing from outer region to inner regions of the GMC cores, implying that the magnetic force is playing an important role in GMCs. The magnetic field of the GMCs was derived from the molecular emission and simple models.
These results were recently published in the Astrophysical Journal, Volume 745,Issue 1, article id. 47 (2012). http://adsabs.harvard.edu/abs/2012ApJ...745...47L