At the end of the Dark Ages, about 0.6-0.7 billions years after the Big Bang (corresponding to redshift z ~ 8-9), the very first energetic sources such as type O-B stars and quasars begin to form and reionise the Universe, which was neutral until that epoch. The very complex dynamics of the reionisation process and the role of ionisation sources, especially during the epoch corresponding to the redshift window 2.5 < z < 8.5, remain vastly unexplored on cosmological scales. Existing and upcoming radio-telescopes like CHIME, HIRAX, LOFAR, CONCERTO (p.i. G. Lagache, LAM) and SKA-1 are designed to address these questions using intensity mapping (IM), a very promising technique that consists in performing a low angular resolution survey to map the 21cm emission or the atomic [CII] line emission from unresolved galaxies or HI clouds. Contrary to galaxy redshift surveys, IM can survey efficiently very large cosmological volumes; nonetheless, the cosmological signal is strongly masked by galactic and extra-galactic foregrounds. The Master thesis is devoted to simulate HI catalogues using Monte Carlo techniques starting from dark matter haloes catalogue and to model and analyse the IM simulated maps by means of Minkowski functionals, going beyond the traditional two-point statistics.

Morphology of cosmic reionisation from intensity mapping

Spina, Benedetta
2019/2020

Abstract

At the end of the Dark Ages, about 0.6-0.7 billions years after the Big Bang (corresponding to redshift z ~ 8-9), the very first energetic sources such as type O-B stars and quasars begin to form and reionise the Universe, which was neutral until that epoch. The very complex dynamics of the reionisation process and the role of ionisation sources, especially during the epoch corresponding to the redshift window 2.5 < z < 8.5, remain vastly unexplored on cosmological scales. Existing and upcoming radio-telescopes like CHIME, HIRAX, LOFAR, CONCERTO (p.i. G. Lagache, LAM) and SKA-1 are designed to address these questions using intensity mapping (IM), a very promising technique that consists in performing a low angular resolution survey to map the 21cm emission or the atomic [CII] line emission from unresolved galaxies or HI clouds. Contrary to galaxy redshift surveys, IM can survey efficiently very large cosmological volumes; nonetheless, the cosmological signal is strongly masked by galactic and extra-galactic foregrounds. The Master thesis is devoted to simulate HI catalogues using Monte Carlo techniques starting from dark matter haloes catalogue and to model and analyse the IM simulated maps by means of Minkowski functionals, going beyond the traditional two-point statistics.
2019-10-14
77
cosmology, dark matter, reionization epoch
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12608/22073