To develop a complete picture of the early stages of star and planet formation, it is necessary to understand the molecular clouds from which they form. The physical properties of these clouds and the interactions between their gas and solid constituents are not well known. This thesis presents an observational study of the morphology and kinematics of carbon monoxide(CO) gas in molecular clouds. It forms part of a wider project to produce the first coupled gas-solid maps of a broad sample of starless and star forming clouds. Nine molecular clouds were observed with the James Clerk Maxwell Telescope, the Institut de Radio Astronomie Millimétrique 30 m Telescope and the Nobeyama 45 m Radio Telescope to produce large scale(14.6 × 14.6 arcmin), high resolution (15.3 arcsec) maps of CO emission.The COROLINE software was developed to derive maps from the observations which show how the CO gas is distributed; the temperature and density structures of the clouds; and how the morphology and kinematics of CO gas is influenced by embedded and nearby stars. A comprehensive analysis is made of Barnard 35A: a cloud heavily processed both internally by a young stellar object and externally by massive stars. The temperature, density and velocity structures of this cloud are explored in detail. Observational evidence is proposed for photoelectric heating through a correlation between the gas temperature and emission from PolyAromatic Hydrocarbons. A clump of enhanced emission ahead of a Herbig–Haro object is thought to be due to photodesorption of CO ice from the surface of dust grains. A chain of similar clumps, following an arc equidistant from the YSO, suggest that the outflow is precessing. This work concludes with the first coupled gas-solid maps. This thesis demonstrates the importance of understanding the often complex morphology and kinematics of a star forming region prior to considering the interactions between its gas and solid-phase species.
|Date of Award||1 Apr 2010|
- University Of Strathclyde
|Supervisor||Benjamin Hourahine (Supervisor) & (Supervisor)|