Abstract
In this thesis We will look at the effects of the Wouthuysen-Field coupling of Lyα on the IGM surrounding a central source at z = 25 with an ionized bubble, powerlaw UV spectrum, atomic and molecular hydrogen absorption features, when assuming wing scattering affects the radial distribution of photons in the thermal core.
We will first go through the physics describing the universe during the dark ages and reionisation of the universe, and the structure formation which culminates in galaxy and star formation. Then we will look at the 21cm hyperfine transition of the hydrogen atom, before describing the model and its implications.
Throughout the thesis we will attempt to describe the causality chain which leads to star formation, but discussing global distributions like correlation functions, IMF, luminosity functions, power spectra is beyond the scope of this thesis. We have also tried to keep avoiding showing best fit values from models with numerical estimates, unless directly applicable to the model, and we try to emphasise the underlying physics.
Throughout the thesis we have tried to stick to SI units for numerical values, so the reader with experience in this field using cgs is cautioned to keep this in mind. The formulae, however, are all in cgs, as is customary in this field.
Veileder: Førsteamanuensis Mark Dijkstra, Institutt for teoretisk astrofysikk, UiO
Intern sensor: Professor David F. Mota, Institutt for teoretisk astrofysikk, UiO
Ekstern sensor: Professor Andrei Mesinger, Scuola Normale Superiore, Pisa, italia