PhD ceremony: Mr. M.A. Latife, 14.45 uur, Aula Academiegebouw, Broerstraat 5, Groningen
Dissertation: Cosmological simulations of the first galaxies
Promotor(s): prof. S. Zaroubi, prof. M.C. Spaans
Faculty: Mathematics and Natural Sciences
The prime objective of this thesis is to study the formation of the first galaxies. We have performed high resolution cosmological simulations using the code FLASH.
We find that by trapping Lyman alpha photons temperature of the protogalactic halo remains higher or equal to 104 K. Consequently, fragmentation to stellar masses remains inhibited and makes such halos the potential sites for the formation of black holes. We also compared our results with atomic as well as molecular hydrogen cooling halos and found significant differences. We also estimated the emission of Lyman alpha photons from the first galaxies. We find that gas falls into the center of a galaxy through cold streams of gas and results in the emission of Lyman alpha photons. The emission of Lyman alpha photons is extended and Lyman alpha flux of 10−17 erg/s/cm2 is produced which can be detected with upcoming James Webb Space telescope. We also studied the impact of background UV flux on the emission of Lyman alpha radiation from the first galaxies and its implications for the formation of molecules in primordial gas. We find that the presence of a background UV flux enhances the emission of Lyman alpha photons and influences the formation of molecules in the primordial gas. We found that the 21 cm signal that emanates from the cosmic dark ages is very weak in the absence of radiation sources and will be difficult to observe.
Households that own their own home paid 776 euros to the municipality on average this year, which is 5.0 percent more than last year. 295 euros of this amount covers the immovable property tax (ozb), 283 euros are paid for waste collection levy, and...
1.5 miljoen euro voor De Donkerte van het Waddengebied
Three researchers from the University of Groningen have been awarded an ERC Advanced Grant. These three researchers are Prof. Gerard Roelfes (Stratingh Institute for Chemistry), Prof. Leon Koopmans (Kapteyn Astronomical Institute) and Prof. Erwin de...