{"id":{"repo_id":"durham","oai_identifier":"oai:etheses.durham.ac.uk:377"},"canonical_url":"https://search.dev.ndltd.org/etd/durham/oai:etheses.durham.ac.uk:377","repository":{"repo_id":"durham","name":"Durham University","base_url":"http://etheses.dur.ac.uk/cgi/oai2"},"display":{"title":"Galaxy Formation in the Lambda-Cold Dark Matter Cosmology","abstract":"In this thesis I explore the effects of the various physical processes behind galaxy formation and evolution in hierarchical cosmologies by using semi-analytical modelling. I use the Durham semi-analytical model GALFORM. I first test the GALFORM model predictions using observations from the Sloan Digital Sky Survey (SDSS). I use two different variants of the model, Baugh et al (2005), which assumes a top-heavy initial mass function (IMF) in starbursts and superwind feedback, and Bower et al (2006), which incorporates AGN feedback with a standard IMF. I compare the luminosity function, colours, sizes and morphology distributions of present-day galaxies in the models and with the SDSS. The Bower et al model better reproduces the shape of the luminosity function, the morphology-luminosity relation and the colour bimodality observed in the SDSS data. The Baugh et al model is much more successful at predicting galaxy sizes for late-type galaxies. Both models have problems with the sizes of early-type galaxies, which are predicted to be too large for low luminosities and too small for high luminosities compared to SDSS. I tested the impact on the model predictions of varying the prescriptions for supernova feedback, disk instabilities and galaxy mergers. In the second part of the thesis I explore the connection between two high redshift star-forming galaxy populations and present-day galaxies and their contribution to the star formation history. I built galaxy merger trees and followed the evolution and properties of submillimetre galaxies (SMGs) and Lyman-break galaxies (LBGs) using the Baugh et al (2005) model. The model predicts that the descendants of SMGs (S_{nu} > 5 mJy) have a median stellar mass of ~10e11/h solar masses, and that more than 70% of these descendants are bulge-dominated. More than 50% of present-day galaxies with stellar masses larger than 7 x 10e11/h solar masses are predicted to be descendants of such SMGs. Somewhat controversially, the stellar mass produced in the submillimetre phase contributes only 0.2% of the total present-day stellar mass, and 2% of the stellar mass of SMG descendants. The descendants of z=3 LBGs are predicted to have a median stellar mass equal to that of the Milky Way (M = 4 x 10e10/h solar masses), while the descendants of z=6 LBGs are predicted to have a larger median stellar mass (M = 10e11/h solar masses). The model predicts that only one in every 16 and one in every 50 Milky Way mass galaxies have a Lyman-break galaxy progenitor at z=3 and z=6 respectively.","abstract_html":"In this thesis I explore the effects of the various physical processes behind galaxy formation and evolution in hierarchical cosmologies by using semi-analytical modelling. I use the Durham semi-analytical model GALFORM. I first test the GALFORM model predictions using observations from the Sloan Digital Sky Survey (SDSS). I use two different variants of the model, Baugh et al (2005), which assumes a top-heavy initial mass function (IMF) in starbursts and superwind feedback, and Bower et al (2006), which incorporates AGN feedback with a standard IMF. I compare the luminosity function, colours, sizes and morphology distributions of present-day galaxies in the models and with the SDSS. The Bower et al model better reproduces the shape of the luminosity function, the morphology-luminosity relation and the colour bimodality observed in the SDSS data. The Baugh et al model is much more successful at predicting galaxy sizes for late-type galaxies. Both models have problems with the sizes of early-type galaxies, which are predicted to be too large for low luminosities and too small for high luminosities compared to SDSS. I tested the impact on the model predictions of varying the prescriptions for supernova feedback, disk instabilities and galaxy mergers. In the second part of the thesis I explore the connection between two high redshift star-forming galaxy populations and present-day galaxies and their contribution to the star formation history. I built galaxy merger trees and followed the evolution and properties of submillimetre galaxies (SMGs) and Lyman-break galaxies (LBGs) using the Baugh et al (2005) model. The model predicts that the descendants of SMGs (S_{nu} > 5 mJy) have a median stellar mass of ~10e11/h solar masses, and that more than 70% of these descendants are bulge-dominated. More than 50% of present-day galaxies with stellar masses larger than 7 x 10e11/h solar masses are predicted to be descendants of such SMGs. Somewhat controversially, the stellar mass produced in the submillimetre phase contributes only 0.2% of the total present-day stellar mass, and 2% of the stellar mass of SMG descendants. The descendants of z=3 LBGs are predicted to have a median stellar mass equal to that of the Milky Way (M = 4 x 10e10/h solar masses), while the descendants of z=6 LBGs are predicted to have a larger median stellar mass (M = 10e11/h solar masses). The model predicts that only one in every 16 and one in every 50 Milky Way mass galaxies have a Lyman-break galaxy progenitor at z=3 and z=6 respectively.","abstract_has_math":false,"creators":["Gonzalez-Gutierrez, Juan Esteban"],"institution":"Durham University","degree_name":"PhD","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010","date_published":"2010","updated_at":"2026-07-24T02:11:07Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Gonzalez-Gutierrez, Juan Esteban"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2010"]},{"key":"dc:date.issued","label":"Date","values":["2010"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Physics, Department of"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["Durham University"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://etheses.durham.ac.uk/id/eprint/377/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["PhD"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://etheses.durham.ac.uk/id/eprint/377/1/JEGonzalezPhDThesis.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In this thesis I explore the effects of the various physical processes behind galaxy formation and evolution in hierarchical cosmologies by using semi-analytical modelling. I use the Durham semi-analytical model GALFORM. I first test the GALFORM model predictions using observations from the Sloan Digital Sky Survey (SDSS). I use two different variants of the model, Baugh et al (2005), which assumes a top-heavy initial mass function (IMF) in starbursts and superwind feedback, and Bower et al (2006), which incorporates AGN feedback with a standard IMF. I compare the luminosity function, colours, sizes and morphology distributions of present-day galaxies in the models and with the SDSS. The Bower et al model better reproduces the shape of the luminosity function, the morphology-luminosity relation and the colour bimodality observed in the SDSS data. The Baugh et al model is much more successful at predicting galaxy sizes for late-type galaxies. Both models have problems with the sizes of early-type galaxies, which are predicted to be too large for low luminosities and too small for high luminosities compared to SDSS. I tested the impact on the model predictions of varying the prescriptions for supernova feedback, disk instabilities and galaxy mergers. In the second part of the thesis I explore the connection between two high redshift star-forming galaxy populations and present-day galaxies and their contribution to the star formation history. I built galaxy merger trees and followed the evolution and properties of submillimetre galaxies (SMGs) and Lyman-break galaxies (LBGs) using the Baugh et al (2005) model. The model predicts that the descendants of SMGs (S_{nu} > 5 mJy) have a median stellar mass of ~10e11/h solar masses, and that more than 70% of these descendants are bulge-dominated. More than 50% of present-day galaxies with stellar masses larger than 7 x 10e11/h solar masses are predicted to be descendants of such SMGs. Somewhat controversially, the stellar mass produced in the submillimetre phase contributes only 0.2% of the total present-day stellar mass, and 2% of the stellar mass of SMG descendants. The descendants of z=3 LBGs are predicted to have a median stellar mass equal to that of the Milky Way (M = 4 x 10e10/h solar masses), while the descendants of z=6 LBGs are predicted to have a larger median stellar mass (M = 10e11/h solar masses). The model predicts that only one in every 16 and one in every 50 Milky Way mass galaxies have a Lyman-break galaxy progenitor at z=3 and z=6 respectively."]},{"key":"dc:format","label":"Dc Format","values":["text"]},{"key":"dc:title","label":"Title","values":["Galaxy Formation in the Lambda-Cold Dark Matter Cosmology"]}]}],"canonical_facts":{"dc:creator":["Gonzalez-Gutierrez, Juan Esteban"],"dc:date":["2010"],"dc:date.issued":["2010"],"dc:description.abstract":["In this thesis I explore the effects of the various physical processes behind galaxy formation and evolution in hierarchical cosmologies by using semi-analytical modelling. I use the Durham semi-analytical model GALFORM. I first test the GALFORM model predictions using observations from the Sloan Digital Sky Survey (SDSS). I use two different variants of the model, Baugh et al (2005), which assumes a top-heavy initial mass function (IMF) in starbursts and superwind feedback, and Bower et al (2006), which incorporates AGN feedback with a standard IMF. I compare the luminosity function, colours, sizes and morphology distributions of present-day galaxies in the models and with the SDSS. The Bower et al model better reproduces the shape of the luminosity function, the morphology-luminosity relation and the colour bimodality observed in the SDSS data. The Baugh et al model is much more successful at predicting galaxy sizes for late-type galaxies. Both models have problems with the sizes of early-type galaxies, which are predicted to be too large for low luminosities and too small for high luminosities compared to SDSS. I tested the impact on the model predictions of varying the prescriptions for supernova feedback, disk instabilities and galaxy mergers. In the second part of the thesis I explore the connection between two high redshift star-forming galaxy populations and present-day galaxies and their contribution to the star formation history. I built galaxy merger trees and followed the evolution and properties of submillimetre galaxies (SMGs) and Lyman-break galaxies (LBGs) using the Baugh et al (2005) model. The model predicts that the descendants of SMGs (S_{nu} > 5 mJy) have a median stellar mass of ~10e11/h solar masses, and that more than 70% of these descendants are bulge-dominated. More than 50% of present-day galaxies with stellar masses larger than 7 x 10e11/h solar masses are predicted to be descendants of such SMGs. Somewhat controversially, the stellar mass produced in the submillimetre phase contributes only 0.2% of the total present-day stellar mass, and 2% of the stellar mass of SMG descendants. The descendants of z=3 LBGs are predicted to have a median stellar mass equal to that of the Milky Way (M = 4 x 10e10/h solar masses), while the descendants of z=6 LBGs are predicted to have a larger median stellar mass (M = 10e11/h solar masses). The model predicts that only one in every 16 and one in every 50 Milky Way mass galaxies have a Lyman-break galaxy progenitor at z=3 and z=6 respectively."],"dc:format":["text"],"dc:identifier.uri":["https://etheses.durham.ac.uk/id/eprint/377/1/JEGonzalezPhDThesis.pdf"],"dc:publisher.department":["Physics, Department of"],"dc:publisher.institution":["Durham University"],"dc:relation.isreferencedby":["https://etheses.durham.ac.uk/id/eprint/377/"],"dc:title":["Galaxy Formation in the Lambda-Cold Dark Matter Cosmology"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["PhD"]},"updated_at":"2026-07-24T02:11:07Z"}