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 20 of 34 for “"Ia Supernovae"”.
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Type Ia supernovae as tools for cosmology
Includes abstract. Includes bibliographical references (leaves 95-100).
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LUMINOSITY DISTRIBUTIONS AND ABUNDANCE TOMOGRAPHY MODELLING OF TYPE IA SUPERNOVAE
I present an investigation into Type Ia Supernovae (SNe Ia). The aim of this investigation is to explain the physics and diversity of SNe Ia, motivated by the fact that, although SNe Ia are known to come from a thermonuclear explosion of a C+O Chandrasekhar mass (Ch-mass) White Dwarf (WD), their …
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Understanding Type Ia Supernovae Through Their Host Galaxies Using the SDSS-II Supernova Survey
… energy was made possible by the study of Type Ia supernovae. These thermonuclear explosions of white dwarfs are excellent standardizable candles that can be seen out to great distances and used to constrain cosmological parameters. However, in an era when modern surveys are discovering hundreds …
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The fates of binary companions in Type Ia supernovae within the single-degenerate scenario
Type Ia supernovae (SNe~Ia) are thought to be caused by thermonuclear explosions of carbon-oxygen white dwarfs in close binary systems. However, the nature of the progenitor systems is still uncertain. In the single-degenerate scenario (SDS), the companion star is non-degenerate and can be …
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Cosmology Using Photometric Samples of Type Ia Supernovae: The First Joint Photometric Light Curve Analysis
<p>Over the last twenty five years, type Ia supernova (SNIa) have been a crucial cosmological probe, responsible for the discovery of the accelerating expansion of the universe. But with the dawn of the next generation of telescopes and SNIa samples, new methods and techniques are needed to …
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Multi-dimensional Monte Carlo radiative transfer simulations: investigating the double detonation scenario for type Ia supernovae
Type Ia supernovae (SNe Ia) are still poorly understood, despite being widely-studied across many fields of astrophysics. Explosion simulations have shown that sub-Chandrasekhar mass white dwarfs are promising candidates for the progenitors of SNe Ia, and can reproduce a number of the observed …
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Hierarchical Bayesian Spectro-temporal Models of Type Ia Supernovae in the Optical and Near-Infrared: Understanding the Properties of Dust in Supernova Host Galaxies
… Roman Space Telescope both on the horizon, Type Ia supernova (SN Ia) cosmology is about to undergo a paradigm shift. Whilst this new era has the potential to bring unprecedented constraints on the nature of dark energy, this will only be possible if we are able to overcome the considerable …
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SALT spectroscopy and classification of supernova spectra using Bayesian techniques
… These were classified using a new Bayesian Supernova spectra classifier, SuperNovaMC, that we developed to address limitations with existing algorithms. SuperNovaMC simultaneously finds the best fitting supernova and host galaxy using Bayesian model selection, fitting the entire spectrum …
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Investigating the presence and properties of circumstellar material in Type I Supernovae
… explosive deaths experienced by some stars in supernovae explosions has increased significantly over the last several decades, though many outstanding questions remain. The work presented here is comprised of two projects that seek to answer the role that circumstellar material plays in both …
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Unravelling the nature of hydrogen-poor thermonuclear supernovae
Thermonuclear supernovae take many forms, as demonstrated by the increasing evidence of diversity among type Ia supernovae, particularly at early times, and subclasses of peculiar objects. This thesis presents new observations and modelling tools that explore the diversity of thermonuclear …
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Novel methods of supernova classification and type probability estimation
… photometric surveys will provide vastly more supernovae than have presently been observed, the majority of which will not be spectroscopically typed. Key to extracting information from these future datasets will be the efficient use of light-curves. In the first part of this thesis we …
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The type IA supernova rate in intermediate redshift galaxy clusters
Studies of Type Ia supernovae (SNe Ia) in galaxy clusters can tell us about the metal enrichment of the intra-cluster medium, constrain the star formation history of cluster galaxies, aid us in the investigations of the progenitor systems of SNe Ia, act as tracers of the intra-cluster stellar …
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Multimessenger signatures of compact binaries
… I perform an electromagnetic study of Type Ia supernovae in the mid-infrared, whose white dwarf binary progenitors will be mHz gravitational-wave sources for the future LISA space mission.
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Cosmic acceleration and the coincidence problem
… by different observations including Type Ia Supernovae (SNIa), the Cosmic Microwave Background (CMB), Large Scale Structure (LSS), and Weak Lensing (WL). This confirmation however, lacks a fundamental physics explanation. The hypothetical form of energy termed 'dark energy' (DE) assumed to …
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Radiative Corrections to and Connections Among Theories With Lorentz Violation and Time-Varying Couplings
… model. In the electromagnetic sector, a time-variation in the fine structure constant &alpha is studied as a possible mechanism to generate Lorentz, CPT and gauge symmetry violations in quantum electrodynamics. The vacuum polarization diagram and fermion self-energy are studied in order to study …
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Traces of Extra Dimensions in Cosmology
… an overview of extra dimensions, from the initial ideas of Kaluza and Klein to the more recent concept of braneworld models and in particular review the cosmological aspects of the DGP braneworld model, which can produce late time acceleration. We then go on to consider the asymmetric brane …
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Supernova Rates, Rise-Ttmes and their Relations to Progenitors
Supernovae are fundamental in astronomy: they inject high mass elements into the interstellar medium enriching the chemistry of galaxies, they feed processes of star formation and active galactic nuclei, and they have been a key for the developments in cosmology of the past decades. This …
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The behavior of hydrogen and helium at white dwarf photosphere conditions
… models, and to constrain the physics of Type Ia supernovae as well as dark energy. Accurate WD masses are needed for all of these applications. In this thesis, I review the weaknesses of the currently available WD mass determination methods and show that for hydrogen-dominated WDs, such …
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Exotic Stars and Thorne-Żytkow Objects
… Common Envelope Evolution (CEE) event between a giant or supergiant star with a neutron star companion. It consists of a large, diffuse giant envelope surrounding a neutron degenerate core. We investigate the structure and evolution of these objects here. Focusing on the central degenerate …
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