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Mc Leod, Anna Faye (2016): Feedback in massive star-forming regions traced by integral field spectroscopy. Dissertation, LMU München: Faculty of Physics



Throughout their entire lives, massive stars have a deep impact on their surroundings (e.g. via protostellar outflows, strong winds, ionising radiation, supernovae events). Conceptually this is well understood, but the exact role of these feedback mechanisms on the global star formation process and the stellar environment, as well as their dependence on the properties of the regions in which massive stars form, are yet to be understood in detail. In this thesis, the effect of ionising feedback from massive stars is analysed with an observational technique called integral field spectroscopy, which yields 3-dimensional information by allowing one to image the target sources not only in one band or wavelength, but across an entire wavelength range. For this purpose an observational setup and novel analysis techniques are first developed, which are then used to derive a correlation between the feedback-driving, ionising massive stars and the feedback-affected surrounding gas structures, after having tested them on a classical star-forming region. It is found that integral field spectroscopy is ideal to trace feedback from massive stars, and that datasets from such instruments can also be used to identify and classify the feedback-driving massive stars. The novel methods and techniques developed in this thesis allowed (i) the computation of the mass-loss rate of molecular cloud structures due to photoionisation from the nearby massive stars; (ii) an observationally-derived quantification of the effect of photoionisation by correlating the mass-loss rate of the cloud structures to the photon flux emitted by the feedback-driving stars; (iii) the analysis of the relative contribution of shock and ionising feedback to the excitation of the cloud matter; (iv) the identification of jets originating from young stars embedded in the molecular cloud structures surrounding the massive stars and the analysis of their kinematics and morphologies with respect to the nearby ionising stars. These results demonstrate that that the developed methods allow the study of the effect of ionising feedback from massive stars, and that they deliver an observational quantification of these effects. This thesis sets the ground for future investigations, which, together with ongoing and planned observational campaigns, are aimed at characterising and quantifying high-mass stellar feedback throughout the evolutionary stages of the feedback-driving stars and their environments. This can lead to crucial insight needed to understand the global process of star formation, i.e. how galaxies turn their gas into stars and how this depends on feedback itself.