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The mechanism by which massive stars form is not nearly as well understood as it is for lower mass stars. For instance, at the onset of massive star formation, it is still not clear whether the mass for a given massive star comes from the turbulent collapse of a dense core (i.e McKee & Tan, 2003) or whether the star continues to accrete material from the cores environment as it grows (i.e. Bonnell et al., 1998). From this point, it is suggested that the cold, massive core (an Infrared Dar Cloud) begins to heat up and form a Hot Core. Later in its protostellar evolution, an HII region forms from the ionizing radiation being produced by the massive star. How, or even whether, accretion onto the massive protostar can continue in the presence of the large outward thermal and radiation pressures from the star is also quite uncertain. Can the star continue to accrete ionized gas (i.e. Keto & Wood, 2006)? Are the accretion rates high enough early on to account for the final observed masses (i.e. Klaassen et al., 2006)? Or, is there some way of minimizing the radiation pressure affecting the infalling gas (i.e. McKee & Ostriker, 2007, and references therein). Here, we present observations which suggest that there is a statistically significant, although short, period in which rotation and infall of molecular gas (which powers a bipolar outflow) continue after the formation of an HII region. This continued infall of material is seen on both large and small scales, and appears to be continuing to produce outflows in many of the sources observed in this study. That it is not seen in all sources suggests that this stage is short lived. / Thesis / Doctor of Philosophy (PhD)

This study consisted of an optical photometric and spectroscopic analysis on a 7′ 7′ field around the Southern high mass star forming region RCW 34. A previous study on RCW 34 in the NIR discov- ered many deeply embedded young stellar objects which were suspected to be T Tauri stars and which justified further investigation. The data used in this study consisted of three sets, the first two are photometric and spectroscopic data sets which were obtained during the first two weeks of February 2002. A third data set of spectroscopic observations was obtained by the author during the second week of 2011 of selected candidates using results from the NIR study and from the photometric data sets. All of the spectroscopy was conducted with the long slit spectrograph on the 1.9-m telescope and the photometry with DANDICAM on the 1.0-m telescope at the South African Astronomical Observatory (SAAO) in Sutherland. Objectives accomplished in the course of this study were to understand, ob- tain, reduce and interpret photometric and long slit spectroscopic CCD images. From the photometric results 57 stars showed excess blue emission on a colour-colour diagram which could be generated by circumstellar matter. The spectroscopic study showed 5 stars that showed H emission and 2 with strong Li absorption lines which confirm the suspicions of the NIR study about T Tauri stars in the region. All of the stars from the spectroscopic study in 2011 were identified as low-mass K or M type stars. Using colour-magnitude diagrams it was possible to see that the majority of the stars in the cluster are low-mass pre-main sequence stars. The stars matching between the optical and NIR filters were plotted on NIR colour-colour diagrams showing that the 5 stars that had H emission lines also had NIR colours characteristic to T Tauri stars. Out of the 5 stars that showed H emission, 2 were found to be classical T Tauris and three were found to be weak line T Tauris. / Thesis (MSc (Space Physics))--North-West University, Potchefstroom Campus, 2013

This study consisted of an optical photometric and spectroscopic analysis on a 7′ 7′ field around the Southern high mass star forming region RCW 34. A previous study on RCW 34 in the NIR discov- ered many deeply embedded young stellar objects which were suspected to be T Tauri stars and which justified further investigation. The data used in this study consisted of three sets, the first two are photometric and spectroscopic data sets which were obtained during the first two weeks of February 2002. A third data set of spectroscopic observations was obtained by the author during the second week of 2011 of selected candidates using results from the NIR study and from the photometric data sets. All of the spectroscopy was conducted with the long slit spectrograph on the 1.9-m telescope and the photometry with DANDICAM on the 1.0-m telescope at the South African Astronomical Observatory (SAAO) in Sutherland. Objectives accomplished in the course of this study were to understand, ob- tain, reduce and interpret photometric and long slit spectroscopic CCD images. From the photometric results 57 stars showed excess blue emission on a colour-colour diagram which could be generated by circumstellar matter. The spectroscopic study showed 5 stars that showed H emission and 2 with strong Li absorption lines which confirm the suspicions of the NIR study about T Tauri stars in the region. All of the stars from the spectroscopic study in 2011 were identified as low-mass K or M type stars. Using colour-magnitude diagrams it was possible to see that the majority of the stars in the cluster are low-mass pre-main sequence stars. The stars matching between the optical and NIR filters were plotted on NIR colour-colour diagrams showing that the 5 stars that had H emission lines also had NIR colours characteristic to T Tauri stars. Out of the 5 stars that showed H emission, 2 were found to be classical T Tauris and three were found to be weak line T Tauris. / Thesis (MSc (Space Physics))--North-West University, Potchefstroom Campus, 2013