Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"galaxy mergers"”.
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Formation of young massive star clusters: a high-resolution multi-wavelength study of intensely star-formation galaxies
… and violent star formation (SF) such as in galaxy mergers and interacting systems. SSCs are thus used as fundamental tools to understand the context of massive SF and galaxy evolution in general. This thesis investigates properties of these young, massive and dense star clusters in a sample …
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The Impact of AGN Feedback on Galaxy Formation in Gas-Rich Mergers at z∼1-2
This thesis studies gas-rich galaxy mergers at redshifts of z ∼ 1-2 using numerical simulations, with a particular focus on the effect of feedback from active galactic nuclei (AGNs). In total, 16 galaxy mergers at redshifts z = 1 and z = 2 were modeled using the simulation codes KETJU and GADGET-3. …
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Infrared-Bright Active Galactic Nuclei in Massive Galaxy Clusters
The number of active galactic nuclei (AGN) in galaxy clusters has been observed to grow by nearly two orders of magnitude from the local universe to z ~ 1.5. Star formation rates in clusters have also been observed to rise rapidly over this redshift interval. These trends, along with several other …
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The Active Phases of a Galaxy in the JWST and Euclid Era: From Radio Jets and Multiphase Outflows to Mergers
… and dust, and shapes the structure of the host galaxy. Another phenomenon that affects galactic evolution is galaxy mergers, as these provide fresh gas, triggering starbursts and fueling black hole activity, sometimes leading to the formation of multiple AGNs within the same system. We first …
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Lyα emission as a sensitive probe of galactic mergers and reionization
… visibility of high-redshift LAEs? We show that galaxy mergers trigger intense starbursts, significantly boosting Lyα luminosity. Additionally, resonant scattering produces extended red wings in the line profiles, which enhance transmission through the neutral intergalactic medium (IGM). Our …
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The Legacy of the First Galaxies: Exploring Ancient Stars in the Milky Way
… ancient systems launched the creation of every galaxy we see today, including the Milky Way. Ever since, for the last 13 billion years, the Milky Way has grown through galaxy mergers. Several of these mergers were with other similarly-sized galaxies and possibly a hundred of these mergers were …
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Outflows and Dust in Quasars
… at 1<z<3, corresponding to the peak epoch of galaxy formation and SMBH growth. First, I make use of recent improvements to atomic energy-level data and photoionisation models to constrain the properties of the Fe III emitting material in quasars. I show that this material must be dense and …
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A new twist on black holes: the role of black hole spin in galaxy formation.
… in a cold dark matter (CDM) universe. The BH and galaxy formation models are coupled: during the evolution of the host galaxy, hot and cold gas are added to the BH by flows triggered by halo gas cooling, disc instabilities and galaxy mergers. This builds up the mass and spin of the BH, and the …
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Simulations of cosmic reionization
… at high redshifts predicted by a semi-analytical galaxy formation model (GALFORM), and combine these to make consistent model of how reionization proceeds. Our improvements to the hybrid characteristics (HC) radiative transport scheme are significant, making the code faster and more accurate, as …
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Dual active galactic nuclei within Romulus25
… of supermassive black holes (SMBHs) during galaxy interactions, while also being an important electromagnetic precursor of SMBH mergers which are important for missions such as LISA. In this thesis, we aim to study the properties of DAGN within the Romulus25 simulation, which combines …
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Far-UV to Mid-IR Spectral Energy Distributions of Nearby Merging Galaxies
Simulations of gas-rich, major galaxy mergers predict elevated amounts of star formation (SF) and nuclear black hole growth (active galactic nuclei, or AGN). This model is supported by observations that find enhanced SF in mergers, but support for the AGN-merger connection remains uncertain. …
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Quasar formation in the context of large scale structure
… in the context of the large-scale structure in galaxy clusters. Our results are somewhat different from what was previously thought - a direct consequence of this new perspective and more powerful methods of analysis. In contrast with previous studies, which relied on the galaxy excess …
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Merging black hole binaries in gaseous environments: simulations in general-relativistic magnetohydrodynamics
… hole-black hole (BHBH) binaries produced in galaxy mergers are promising sources of detectable gravitational waves. If such a merger takes place in a gaseous environment, there is a possibility of a simultaneous detection of electromagnetic and gravitational radiation, as the stirring, shock …
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Galaxy Formation in the Lambda-Cold Dark Matter Cosmology
… 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 …
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The Cluster and Large Scale Environments of Quasars at z < 0.9.
… into the environments of quasars with respect to galaxy clus- ters, and environment evolution with redshift and luminosity. The positions of quasars with respect to clusters have been studied using cluster and quasar catalogues available, covering the redshift range 0.2 < z < 1.2. The 2D projected …