My research project
Engineering Dwarfs at Galaxy Formation's Edge
My project focusses on the physics responsible for the formation of small dwarf galaxies (on the 'edge' of formation). Dwarf galaxies are particularly sensitive to the physics that govern their creation and evolution, and their close proximity to the Milky Way allow them to be observed in great detail. Such observations are often at odds with predictions from theory and from the lambda-CDM cosmological model. This has given rise to the 'Cusp-core problem' and the 'Missing satellite problem', which suggest that there are physics beyond the current theoretical framework.
By running cosmological simulations over a Hubble time (14 Gyr), galaxy formation under the influence of various physics can be investigated. Among other things I will study cusp-core transformations, the effects of reionisation, the importance of radiative feedback, and star cluster formation within ultra-faint dwarfs. The outcome of these investigations will aid in revealing what kind of physics is necessary to produce the dwarf galaxies we observe in our universe today.
9 ) dark matter halo from a cosmological volume, and perform zoom hydrodynamical simulations with multiple alternative histories using ?genetically modified? initial conditions. Earlier-forming ultra-faints have higher stellar mass today, due to a longer
period of star formation before their quenching by reionization. Our histories all converge to the same final
dynamical mass, demonstrating the existence of extended scatter (ý1 dex) in stellar masses at fixed halo mass due to the diversity of possible histories. One of our variants builds less than 2% of its final dynamical mass before reionization, rapidly quenching in situ star formation. The bulk of its final stellar mass is later grown by dry mergers, depositing stars in the galaxy?s outskirts and hence expanding its effective radius. This mechanism constitutes a new formation scenario for highly diffuse (r1 2 ~ 820 pc, ~ - 32 mag arcsec 2 ), metal-poor
([Fe H 2.9 ] = - ), ultra-faint (MV = -5.7) dwarf galaxies within the reach of next-generation low surface