Estado: leído (2012-06-12)
Estudiante(s): Frau, P.
Director(s): Josep Miquel Girart, Beltrán, M. T.
Universidad: Universitat de Barcelona
|The complex interplay among self-gravity, thermal support, turbulence, rotation, and magnetic fields, and ultimately the observable features that arise from them, are not well characterized observationally and, therefore, not well understood theoretically. The fact that the starless cores are diffuse and cold objects, makes them very difficult of observing because their emission is very faint. Our goal in this work is to deepen into the understanding of the formation, survival and evolution of low-mass dense cores. We doubly face this objective since we aim: Firstly, to characterize observationally the physical and chemical properties of magnetized starless dense cores in the earliest stages of evolution to derive the initial conditions for star-formation, and to check whether the magnetic field is playing a role in the evolution of the cores and; Secondly, to compare observations of more evolved Class 0 sources with models of collapse of magnetized clouds to find the most likely initial conditions and dominant physical processes. In order to achieve the first goal, we have selected a sample of starless cores of the Pipe Nebula. This nearby dark molecular cloud complex has a very low star formation efficiency, which makes it an ideal target to study the properties and evolution of pristine starless dense cores. For the second goal, we have selected NGC 1333 IRAS 4A. It is probably the best studied low-mass protostellar dense core, not only through molecular and dust emission, but also through high angular resolution polarimetric observations of the dust emission.|