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 47 for “"host galaxies"”.
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Optical surveys of AGN and their host galaxies
… (AGNs) surveys. The first survey deals with galaxies that host low-level AGNs (LLAGN) and aims at identifying such galaxies by quantifying their variability. While numerous studies have shown that AGNs can be variable at all wavelengths, the nature of the variability is still not well …
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The Host Galaxies of Luminous Reddened Quasars at z~2
The work in this thesis concerns the host galaxies of a class of luminous, yet heavily-obscured, quasars at z$\sim$2 - a peak epoch of both star formation and black hole accretion. Here, we seek to characterise the star-forming properties of these obscured quasars to improve our understanding of …
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Spectral Energy Distribution Modelling of X-ray Selected AGNs and Their Host Galaxies
… between active galactic nuclei (AGN), and their host galaxies have been observed in detail throughout the Universe. Such work has found an intrinsic link between central supermassive black hole (SMBH) masses, and host galaxy properties such as the velocity dispersion of stars, and bulge mass. …
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Understanding Type Ia Supernovae Through Their Host Galaxies Using the SDSS-II Supernova Survey
… these systematics is through the study of the galaxies that host Type Ia supernovae. Correlations have been found between supernova properties and the physical properties of their host galaxies such as mass, metallicity, and star formation rate. In this dissertation, I use supernovae from the …
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A high energy perspective of the co-evolution of black holes and their host galaxies
… fraction of relatively luminous X-ray sources hosting an active, presumably obscured, nucleus would not have been easily recognized as such on the basis of optical observations because characterized by “peculiar” optical properties. In my PhD thesis, I will focus the attention on the nature of …
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How Do Quasars Impact Their Host Galaxies? From the Studies of Quasar Outflows in Absorption and Emission
… accreting supermassive black hole couple to the host galaxy. One mechanism for such a coupling is by high-velocity (up to ~0.2c) quasar-driven ionized outflows, appearing as blue-shifted absorption and emission lines in quasar spectra. Given enough energy and momentum, these outflows are capable …
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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
… to detailed studies of the dust in SN Ia host galaxies – particularly the distribution of the dust law R_V. This model is able to leverage the optical and NIR in a principled manner, whilst coherently marginalising over all sources of uncertainty. I use this model to analyse the Pan-STARRS …
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The Environments of Active Galactic Nuclei
… quasars, radio-quiet quasars and radio galaxies (RLQs, RQQs, and RGs respectively) are presented. The quasar samples are chosen such that they are well matched in the V-z plane, whilst the RGs are selected so that their radio properties (5 GHz radio power and spectral index)are matched …
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Quasar formation in the context of large scale structure
… clusters. In contrast, the narrow emission line galaxies (NELGs) are found to be extremely weak tracers of the LSS when investigated through the same procedure. We find that most of the quasars reside within 3h 1 Mpc from the centre of a galaxy cluster with comparable redshift, but only about 20% …
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The AGN-host galaxy connection : new insights from the extended ionised gas
… can exceed the integrated luminosity of their host galaxies by orders of magnitude, which are then classified as Quasi-Stellar Objects (QSOs). Some mechanisms are needed to trigger the nuclear activity in galaxies and to feed the nuclei with gas. Among several possibilities, such as …
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Studying galaxy formation through Lyman alpha in emission and absorption
… is an important signature of early, starforming galaxies. Both populations, however, present significant theoretical challenges. As part of my thesis, I have developed a Monte Carlo Lyα radiative transfer code to investigate models of early galaxies. Rauch et al. (2008) performed an ultra-deep …
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Core-collapse supernovae in the great survey era
… due to unexpected large dust obscuration in host galaxies, or because some core-collapse events proceed directly to black hole formation and fail to give an optical outburst. Another way to uncover optically invisible supernovae would be the next generation radio telescope, the Square …
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Multiphase Galactic Outflows: Physical Properties and Feedback Effects
… to regulate or even suppress star formation in galaxies. One feedback route is through galactic outflows, which eject large amounts of gas and thereby remove the fuel for future star formation. Such galactic outflows can be driven by active galactic nuclei (AGN) or processes associated with star …
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A near-infrared view of luminous quasars: black hole masses, outflows and hot dust
Supermassive black holes (BHs) and their host-galaxies are thought to evolve in tandem, with the energy output from the rapidly-accreting BH regulating star formation and the growth of the BH itself. The goal of better understanding this process has led to much work focussing on the properties of …
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Accreting Compact Objects in Technicolor: Multiwavelength Characterization of High Mass X-ray Binaries in the Local Group
… population demographics of HMXBs in Local Group galaxies M31 and the Small Magellanic Cloud (SMC) and the spatially resolved recent star formation history (SFH) of M33. In M31, I used observations from the Hubble Space Telescope (HST), the Chandra X-ray Observatory, and the Nuclear Spectroscopic …
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The complex interplay between AGN jet feedback and galaxy evolution
… holes (SMBHs), residing in the nuclei of most galaxies, are capable of imparting extreme amounts of energy to their surroundings. Observations indicate the presence of collimated, relativistic jets as well as powerful, multiphase winds emanating from these active galactic nuclei (AGN). Whilst …
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No evidence for millimeter continuum source overdensities in the environments of z [greater than approximately] 6 quasars
Bright high-redshift quasars (z > 6), hosting supermassive black holes (M [subscript BH] > 10⁸M [subscript circled dot]), are expected to reside in massive host galaxies embedded within some of the earliest, most massive galaxy overdensities. We analyze 1.2mm ALMA dust continuum maps of 35 bright …
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Investigating the role of ionised outflows in galactic evolution through spatially resolved spectroscopy
… trigger, regulate and suppress star formation in galaxies remains one of the main questions in astronomy today. Theoretical models and cosmological simulations of galaxy formation and evolution frequently employ feedback mechanisms from active galactic nuclei (AGN) and supernovae (SNe) to quench …
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Investigating the nature of Peculiar Supernovae and Fast Radio Bursts via their multi-wavelength properties and environments
… from imaging telescopes, I identified likely host galaxies for three FRBs, revealing star-forming galaxies in early-type and transitional evolutionary stages as common FRB hosts. Additionally, a search for persistent radio sources (PRS) associated with repeating FRBs found that most repeating …
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Supernova Rates, Rise-Ttmes and their Relations to Progenitors
… 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 dissertation presents a set of subluminous type Ia supernovae (SNe Ia) at z>0.1 from the …
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