Thesis Topic: Roasting a Giant Molecular Cloud


Thesis Supervisors: Thomas Stanke and Christian Hummel


The young Galactic star-burst cluster NGC3603 is related to a substantial reservoir of molecular gas, located in two Giant Molecular Clouds to its north and south. The clouds have the potential to form even more stars and might significantly contribute to further growth of the cluster.
We propose a study of the properties of the dense gas cores within the Giant molecular clouds and the protostar population, in particular the luminous infrared source IRS9a, a candidate O-star still associated with a protostellar accretion disk.
The study will be based on sub-millimetre wavelength single-dish (APEX) and interferometry (ALMA) data and infrared interferometric data (VLTI). We have obtained APEX ArTeMiS 350 and 450mum dust continuum maps of the clouds revealing the population of dense cloud cores (data exist). We have a presently an ongoing APEX PI230 spectroscopy project to map a variety of molecular lines including CO, H2CO (temperature tracer), SiO (tracer of shocks in outflows), and more. ALMA observations of the region are also planned (dust continuum and molecular lines, with a similar set of lines as in the ongoing APEX observations). We have been awarded time at the VLTI to use MATISSE at mid-infrared wavelengths to image the distribution of warm dust in the immediate surroundings of the IRS9a high mass young stellar object (observations scheduled in February).

The goals of the project will be to

  •  determine the impact of the massive cluster on the neighbouring clouds:
    how does the energy input (heat) influence the star formation process
    throughout the cloud, e.g., by changing the fragmentation properties of
    the dense cores?
  • explore the content of protostars of the cloud and determine their
    characteristics (to which extent do massive stars still form in the clouds?)
  • confirm the nature of IRS9a as an accreting, O-type protostar.