Far From Home: The science exploitation of the fastest milky way stars
- F.A.E. Evans
- Wednesday 15 March 2023
2311 GJ Leiden
- Dr. E.M. Rossi
- Prof.dr. K. Kuijken
Typical stars in the Milky Way travel with velocities of approximately 100-300 kilometres per second. There are notable exceptions to this, however, as stars are now being discovered which have velocities up to and in excess of a thousand kilometres per second. Extreme phenomena are required to explain the ultra-high velocities of these stars, such as dynamical interactions with supermassive black holes or the violent supernova deaths of massive stars. The era of large Galactic surveys including the European Space Agency's Gaia mission is revolutionizing our understanding of fast stars and the Galaxy in general. In my PhD thesis entitled "Far from home: the science exploitation of the fastest Milky Way stars" I present my work on showing how current and future observations of the fastest stars can help constrain still-uncertain aspects of these extreme phenomena. I start by showing how the known population of fast stars ejected from the Galactic disc shed light on the final stages of stellar evolution in binaries and the formation dynamics of black holes. I next predict how many fast stars ejected from the Large Magellanic Cloud (the largest dwarf galaxy companion to the Milky Way) should be detectable in upcoming surveys of the Galaxy. Finally, exploiting the latest observations from the Gaia space mission, I show how observations of the fastest stars constrain the stellar environment of the Galactic Centre, in which lurks the supermassive black hole Sagittarius A*.
Approximately one week after the defence, PhD dissertations by Leiden PhD students are available digitally through the Leiden Repository, that offers free access to these PhD dissertations. Please note that in some cases a dissertation may be under embargo temporarily and access to its full-text version will only be granted later.
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