| Abstract : | Stars form in the densest regions of molecular clouds which are actually gravitationally unstable cores that resides at the junction of filaments. The formation of dense cores and the filaments is a crucial step in the star formation process and their association indicates that the filaments play a central role in the process of forming stars. However, even with a plethora of observational and theoretical information available, the role of turbulence, self-gravity and the magnetic fields in the formation of filamentary structures is still a debated topic. Understanding the connection of the molecular cloud structure with its formation mechanism is crucial in knowing the intricacies of star formation process. In this thesis, the filamentary structures and dense cores in Cepheus Flare region were investigated for their characteristics, dynamics, and the global evolution to address two different scenarios of isolated or triggered star formation. We studied each of these regions by means of large-scale molecular line observations in the range of millimeter or sub-millimetre wavelengths by choosing tracers like C18O, 12CO, 13CO, N2H+ lines sensitive to different density structures in clouds by complimenting with the dust continuum emissions. I further explored the importance of projected motion of the clouds with respect to the cloud scale magnetic fields. Considering the offsets of core orientation over a sample of molecular clouds with cloud-scale magnetic field and direction of motion of the complexes in the galaxy, I studied the importance of magnetic fields and the motion in shaping the cores morphology. The thesis work will be concluded with the study of a set of nearby clouds using magnetic fields with starlight polarization data and the thermal dust emission using Planck to discuss about the impact of magnetic fields on their extended dust emission morphology. |
