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 131 for “"metallicity"”.
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Metallicity correlations in galaxies
… tool for extracting information from the 2D metallicity maps that integral field spectroscopy produces. Using the current integrated field unit observations and simulations, this thesis tries to gradually investigate the following aspects. I show that two-point correlations of current …
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Metallicity correlations in galaxies
… tool for extracting information from the 2D metallicity maps that integral field spectroscopy produces. Using the current integrated field unit observations and simulations, this thesis tries to gradually investigate the following aspects. I show that two-point correlations of current …
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Massive stars in low metallicity environments
… sensitive to mass loss, internal mixing, metallicity, rotation, binarity, and magnetic fields. In this thesis, I have probed the evolution of massive stars for a range of metallicities, including our Milky Way galaxy and the Magellanic Clouds. This work provides an insight into the …
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Shocks and Metallicity Gradients in Normal Star-Forming Galaxies
… explores gas flows in local galaxies by studying metallicity gradients and galactic- scale outflows in normal star-forming galaxies. This is made possible by new integral field spectroscopy data that provide simultaneously spatial and spectral information of galaxies. First, I measure metallicity …
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THE CEPHEIDS OF M33: DISTANCE AND METALLICITY EFFECTS THROUGH SLOAN FILTERS
… are therefore imparted with varying levels of metallicity. The difference in Cepheid metallicities may give rise to variations in their observable characteristics, leading to changes in the Leavitt Law. These changes may manifest themselves as a metallicity dependence on the slope or zero-point …
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Probing the history of galaxy clusters with metallicity and entropy measurements
… spatially resolved measurements of their metallicity and entropy content. A sample of 45 nearby clusters observed with Chandra is analyzed to produce radial density, temperature, entropy and metallicity profiles. The entropy profiles are computed to larger radial extents than in previous …
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The effective temperatures and physical properties of red supergiants : the effects of metallicity.
… to demonstrate a correlation between galactic metallicity and the average spectral subtype of a galaxy's RSG population. Research contained in this thesis has been published in part by the Astrophysical Journal, v. 628, p. 973 Research contained in this thesis has been submitted to the …
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On the evolution of star forming galaxies : the metallicity of dwarfs and the effect of environment on local luminous IR galaxies
… "On evolution of star forming galaxies: the metallicity of dwarfs and the effect of environment on local luminous infrared galaxies" is divided into two main areas. First a detailed study of the environment and star formation relationship of local Luminous Infrared Galaxies (LIRGs), with …
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The stellar halos of Milky Way type galaxies in the EAGLE simulations
… of MW-mass disc galaxy stellar halos. Negative metallicity gradients are ubiquitous in the galaxy samples analysed, with gradients in the range -0.002 to -0.02 dex/kpc, consistent with recent observations of M31. The gradient was found to be primarily driven by the transition from high …
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The structure of the Large Magellanic Cloud
This work gives an account of the study of the metallicity [Fe/H] distribution (gradient) in the oldest population in the Large Magellanic Cloud (LMC), by making use of the available RR Lyrae data from the Optical Gravitational Lensing Experiment III (OGLE III). RR Lyrae stars are amongst the …
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The structure of the large magellanic cloud
This work gives an account of the study of the metallicity [Fe/H] distribution (gradient) in the oldest population in the Large Magellanic Cloud (LMC), by making use of the available RR Lyrae data from the Optical Gravitational Lensing Experiment III (OGLE III). RR Lyrae stars are amongst the …
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The accuracy of integrated star clusters parameters. The effects of stochasticity /
… physical parameters (age, mass, extinction, and metallicity) of star clusters with integrated broad-band photometry are traditionally derived using the Simple Stellar Population models (SSP). However, parameters are inaccurate because the models do not take the stochastic sampling of star mass in …
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Integralinių žvaigždžių spiečių parametrų tikslumas. Stochastiniai efektai /
… physical parameters (age, mass, extinction, and metallicity) of star clusters with integrated broad-band photometry are traditionally derived using the Simple Stellar Population models (SSP). However, parameters are inaccurate because the models do not take the stochastic sampling of star mass in …
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Metallicities and stellar populations in spiral bulges
… stellar populations of approximately solar metallicity or above. In bulges, central line-strengths are shown to lie close to, or within, the loci defining solar abundance ratio SSPs. The large number (24) of indices measured in this study, in conjunction with models of the effects of varying …
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New Insights on the Evolutionary Mechanisms of Local and Distant Galaxies
… metallicities and the real drivers of the mass-metallicity relation (MZR) and fundamental metallicity relation (FMR) on both resolved and global scales. I find evidence for a resolved version of the FMR and also that local metallicity depends on both local and global galactic properties, hence …
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Chemodynamical Adaptive Mesh Refinement Simulations of Disk Galaxies
… is used to compare properties such as the metallicity gradients and morphology to determine if systematic differences are apparent as a function of subtle environmental differences. Almost no distinction is seen between galaxies in the field and the loose group environments: individual …
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Improving the extragalactic distance scale using Cepheids in M33
… arisen in its calibration, namely the effect of metallicity on the period-luminosity relation. It is important that we quantify this effect as Cepheids are used to tie down the base of the extragalactic distance scale. Without an accurate calibration for the nearest distances, the distances we …
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Planets around cool stars: a spectroscopic and photometric study of M dwarfs and their planets
… poorly established stellar parameters (radius, metallicity, etc.). For this dissertation I have worked to mitigate these problems with the goals of finding new transiting planets and establishing the role of stellar metallicity on the size and occurrence of transiting planets around M dwarfs. I …
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Evolution of Galaxies - Star Formation Histories in Nearby Spheroids
… particularly sensitive to a galaxy's age and metallicity were measured as equivalent widths and then calibrated to the common scale of the Lick Indices. The Lick Indices were used in deriving all key results throughout the thesis. The modelled sample of galaxies from Proctor & Sansom (2002) …
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