title: Constraining the Physics of the Intergalactic and Circumgalactic Media with Lyman-alpha Absorption
creator: Sorini, Daniele
subject: ddc-520
subject: 520 Astronomy and allied sciences
subject: ddc-530
subject: 530 Physics
description: Lyman-alpha (Ly-a) absorption features detected in quasar spectra in the redshift range 0<z<6 are a powerful tool to probe the intergalactic and circumgalactic media (IGM and CGM) and, consequently, to constrain models of galaxy formation and cosmology. In the first part of this thesis, I overcome certain numerical challenges posed by cosmological hydrodynamic simulations by developing a novel semi-analytic technique to predict various statistics of the Ly-a absorption in the IGM with large N-body cosmological simulations. The technique developed in this work is more accurate than previous attempts in the literature. More importantly, it can be applied on Gpc-scale N-body simulations, allowing an accurate investigation of the Ly-a absorption at unprecedentedly large scales. In the second part of the thesis, I consider observations of Ly-a absorption in spectra of background quasars at different transverse separations (between 25 kpc and 17 Mpc) from foreground galaxies, and compare them with the predictions of different state-of-the-art hydrodynamic cosmological simulations. For the first time, I show that combining observations of Ly-a absorption in the IGM and the CGM can tightly constrain the models of sub-resolution physical processes implemented in simulations (e.g., feedback). With near-future high-precision observations of Ly-a absorption, the tools developed in this work will set the stage for even stronger constraints on models of galaxy formation and cosmology.
date: 2017
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/23691/1/PhD_Thesis_Sorini_heiDOK_PDFA.pdf
identifier: DOI:10.11588/heidok.00023691
identifier: urn:nbn:de:bsz:16-heidok-236915
identifier:   Sorini, Daniele  (2017) Constraining the Physics of the Intergalactic and Circumgalactic Media with Lyman-alpha Absorption.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/23691/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng