| Superbubbles and galactic winds driven by repeated supernova explosions in dwarf galaxies play important roles in galaxy formation and cosmology. The subjects of the present thesis are (1) the study of the effects of supershells and galactic outflows on the escape of ionizing radiation in dwarf starburst galaxies (Chapter 1: Radiative Feedback) and (2) the study of the efficiencies of metal and energy ejection in high-redshift dwarf starburst galaxies (Chapter 2: Metal and Energy Feedback). For both projects, the hydrodynamic simulation code, ZEUS-3D, is used to model the effects of starbursts in dwarf galaxies.; In Chapter 1, I show that the dense shells swept-up by starburst bubbles can effectively trap the ionizing photons before the bubbles blow out of the galactic disks. After the blow-outs, the bubbles form chimneys for the radiation to escape to inter-galactic space. I compare the results with local observations and discuss the evolution of UV background radiation.; In Chapter 2, I show that rather high metal ejection efficiencies of 50% and moderate energy ejection efficiencies of ≈20% can be expected in dwarf galaxies with virial temperature a few ×104 K with star formation efficiencies f* ≈ 1%. I discuss the role of such metal feedback in enriching the intergalactic medium and the role of energy feedback in suppressing the formation of other dwarf galaxies. |
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