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 9 of 9 for “"stellar spectra"”.
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A pipeline for the analysis of stellar spectra
… are able to turn raw data files into tables of stellar parameters and chemical abundances in far less time than if they were analysed by hand. The results from these surveys open new windows on to the history of our galaxy and other disk galaxies. In this thesis, we present the development of a …
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Classification of Stars from Redshifted Stellar Spectra utilizing Machine Learning
The classification of stellar spectra is a fundamental task in stellar astrophysics. There have been many explorations into the automated classification of stellar spectra but few that involve the Sloan Digital Sky Survey (SDSS). Stellar spectra from the SDSS are applied to standard classification …
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Unearth: Revealing the Effects of Stellar Activity on Exoplanet Host Stars
… thesis, I investigate the effect activity has on stellar spectra, using HARPS data of the well observed K1 V star α Centauri B. I compare spectra from high- and low-activity periods (as traced by log R′HK) of α Cen B. I produce ‘relative spectra’ by dividing the high-activity spectra by a …
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SHEDDING NEW LIGHT ON OLD DATA: FINDING NEW RESULTS FOR EXOPLANET SCIENCE IN ARCHIVAL DATA
… the pipeline I have developed to reduce HST WFC3 spectra of exoplanet hosts during transits to create transmission spectra. This code corrects several instrumental systematics, from varying dark signal in the detector to subpixel shifts in the target position over time. By creating a pipeline to …
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Spectroscopic surface brightness fluctuations
… to study this evolution we can either study the stellar populations, tracing the star formation and chemical enrichment, or the dynamics, tracing interactions and mergers of galaxies as well as accretion. In the last decades this field has become one of the most active research areas in modern …
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Crowded field spectroscopy and the search for intermediate-mass black holes in globular clusters
… These black holes would bridge the gap from stellar mass black holes, that represent the final stage in the evolution of massive stars, to supermassive ones that reside in the centres of galaxies. For this reason, they are referred to as intermediate-mass black holes. The most reliable method …
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A New Library of Stellar Model Atmospheres and Spectra
… of all other stars, galaxies and the interstellar medium are based upon. Libraries of model atmospheres and stellar spectra have been previously computed using ATLAS9 based upon the solar metallicity and chemical composition values calculated by Grevesse & Sauval (1998), used as the …
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Early Stages of Massive Star Formation at High Spatial Resolution
… kinematics of UCHII regions at high spatial and spectral resolution. NIR-polarimetric maps of the reflection nebula that are generally found around these objects are used to rule out the presence of deeply embedded companions of a Young Stellar Object (S106) and to identify multiplicity in the …
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Exoplanetary Systems in Technicolor
… considering the effects of non-homogeneous stellar surfaces on exoplanet observations. I investigate how spatially and time varying surface features of a star contribute to baseline trends that must be removed when analyzing exoplanet transits, and assess the feasibility of empirically …