<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Giant molecular clouds under the influence of the galactic environment"^^ . "The vast majority of star formation in galaxies begins in cold, dense, fractally-structured reservoirs of molecular hydrogen known as giant molecular clouds. The instantaneous\r\nproperties of these clouds and the time-scales on which they evolve can therefore be built up into models of the empirical properties of galactic-scale star formation, and so can be used to understand this process. In this thesis, we first propose a simple analytic framework to quantify the expected variation in the physical properties and lifetimes of giant molecular clouds in response to changes in their galactic-dynamical environments, finding that they vary within a fundamental parameter space spanned by the orbital angular velocity of the host galaxy, the degree of galactic shearing, the gravitational stability, and the mid-plane hydrostatic pressure. We then explore this parameter space using a set of high-resolution numerical simulations of Milky Way-like galaxies. Due to their high densities and pressures relative to the galactic mid-plane, we find that giant molecular clouds in Milky Way-like galaxies are self-gravitating and decoupled from galactic dynamics, by contrast to their lower-density progenitor clouds of atomic gas, which display systematic, galactic-dynamical variations. Finally, we analyse the full evolutionary history of each simulated cloud population as a function of the cloud spatial scale. Across all Milky Way-like environments, we find that the lifetimes of self-gravitating clouds decrease with their spatial scale below the scale-height of the thin gas disc of the galaxy, and converge to the disc crossing time at its scale-height."^^ . "2020" . . . . . . . "Sarah May Rose"^^ . "Jeffreson"^^ . "Sarah May Rose Jeffreson"^^ . . . . . . "Giant molecular clouds under the influence of the galactic environment (PDF)"^^ . . . "Jeffreson-Sarah-2020.pdf"^^ . . . "Giant molecular clouds under the influence of the galactic environment (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Giant molecular clouds under the influence of the galactic environment (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Giant molecular clouds under the influence of the galactic environment (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Giant molecular clouds under the influence of the galactic environment (Other)"^^ . . . . . . "small.jpg"^^ . . . "Giant molecular clouds under the influence of the galactic environment (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #29009 \n\nGiant molecular clouds under the influence of the galactic environment\n\n" . "text/html" . . . "520 Astronomie"@de . "520 Astronomy and allied sciences"@en . .