title: On the formation of the Milky Way system in cosmological context - A numerical study
creator: Buck, Tobias
subject: 500
subject: 500 Natural sciences and mathematics
subject: 520
subject: 520 Astronomy and allied sciences
subject: 530
subject: 530 Physics
description: State-of-the-art cosmological hydrodynamical simulations have succeeded in modelling realistic Milky Way (MW) type galaxies with spatial resolution of the order of a few hundred parsec, similar to the scale-height of MW's stellar disc and the half-light radius of classical satellite galaxies.   I divide the present study into two parts, the build-up of MW's stellar disc and bulge and the formation and evolution of its satellites and dwarf galaxies.     In the first part I show that observed clumpy stellar discs in the early phases of the formation of the Galaxy are dynamically unimportant for its further evolution. This confirms recent observational results where a non linear mapping between stellar mass and light causes stellar discs to appear clumpy.   I turn then to explore the formation mechanism of a peanut bulge in cosmological context. I study the kinematical properties of the central stellar populations of a model galaxy using a kinematical decomposition technique and find that the observed kinematic features of the (MW) bulge can only be explained if it consists of both, a peanut bulge and a spherically symmetric bulge both formed via disc instabilities. Observing and disentangling both components will soon be possible thanks to large scale Galactic surveys like Gaia.    In the second part I study the dwarf galaxy population of (MW) mass galaxies. The simulations presented here are among the first to be able to study the formation of dwarf satellite galaxies in a realistic cosmological environment. The employed sub-grid models of the simulations reconcile simulated and observed Local Group satellite mass functions and produce dwarf galaxies whose central stellar velocity dispersion agrees with observations. Using the dwarf galaxies, I test the observational prospects of identifying tidally affected dwarfs in the Local Group using three observables: their distance, line-of-sight velocity and central velocity dispersion. Finally, I investigate the evolution of planes-of-satellites in the framework of the Cold Dark Matter model with a cosmological constant (ΛCDM). These planes quickly dissolve because they consist of a large fraction of chance aligned satellites as recently confirmed with the proper motions of the classical satellite galaxies derived from Gaia data.
date: 2018
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/25607/1/phd_thesis_buck.pdf
identifier: DOI:10.11588/heidok.00025607
identifier: urn:nbn:de:bsz:16-heidok-256072
identifier:   Buck, Tobias  (2018) On the formation of the Milky Way system in cosmological context - A numerical study.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/25607/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng