Modelling of the Lyman-alpha emission in high redshift galaxies and cosmological simulations
type: Dataset
description: Many galaxies have been detected at high redshift since the late nineties thanks to their strong Lyman-alpha emission line. These objects, knows as Lyman-alpha Emitters, allow us to probe galaxies in the first two Gigayears of the Universe. Although a large amount of detections, their statistical and physical properties are still poorly constrained. Indeed, observations are difficult to interpret, mainly due to line transfer effects in the interstellar mediaum and gas kinematics. In addition to observations, theoretical efforts are needed to reach a better understanding of the properties of these objects, their role in the scenario of hierarchical formation of galaxies, and their link with the other main high redshift galaxy population, the so-called Lyman Break galaxies. In this thesis, we model Lyman-alpha Emitters in the cosmological context with an original method. The hierarchical galaxy formation process is described with the GALICS model, which couples a N body simulation of Dark Matter, with semi-analytic prescriptions to model galaxy physics. GALICS can predict the physical properties of a large sample of mock galaxies between z~3 and 7. Lyman-alpha properties are computed thanks to the coupling of GALICS with a library of numerical tranfser models, generated with the MCLya code. With this approach, Lyman-alpha photons escape fractions and line profiles can be predicted, taking into account resonnant scattering effects and gas kinematics. We find a strong dispersion of the escape fraction with respect to the star formation rate of the galaxies. The model predictions are in good agreement with most of the observationnal data, especially the Lyman-alpha luminosity functions between z~3 and 7. The model is able to reproduce UV properties of UV and Lyman-alpha selected galaxies. We find that Lyman-alpha Emitters have moderate mass on average and display asymetric line profiles, as it is shown by the observations. In particular, we predict a strong abundance of …
identifier: NNT: 2011LYO10223
issued: 2026-05-11T06:34:54.961030
language: fr
modified: 2026-05-11T06:34:54.961035
contact point: Organization
  fn: CCSD
keyword: cosmologie
keyword: cosmology
keyword: evolution
keyword: formation
keyword: galaxies
keyword: grand-decalage-spectral
keyword: high-redshift
keyword: infoeu-reposemanticsdoctoralthesis
keyword: lyman-alpha
keyword: radiative-transfer
keyword: sduothersciences-of-the-universe-physicsother
keyword: theses
keyword: transfert-radiatif
landing page: https://theses.hal.science/tel-00819264

Modelling of the Lyman-alpha emission in high redshift galaxies and cosmological simulations
type: Distribution
format: HTML
issued: 2026-05-11T06:34:54.986154
modified: 2026-05-11T06:34:54.947016
access URL: https://theses.hal.science/tel-00819264

test_moissonnage_selune
type: Agent