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 54 for “"Sloan Digital Sky Survey"”.
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N(th)-Order Correlation Functions of Galaxies From the Sloan Digital Sky Survey
I present the correlation function measurements and analysis I have conducted with SDSS data. I have focused my measurements on angular N-point area-averaged correlation functions (o N(theta)) and auto-correlation functions (o2 (theta)) of galaxies. The measured o N(theta) are used to calculate the …
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The Origins and Environments of Quasar Absorption Lines in the Sloan Digital Sky Survey
Owing to the advent of large spectroscopic surveys such as the Sloan Digital Sky Survey (SDSS), tens of thousands of quasar absorption line (QAL) systems have been identified to date. QAL catalogs currently extend to z ∼ 4.6 and provide unique probes of the large scale structure of baryonic …
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A synoptic survey of narrow quasar absorption lines from the Sloan Digital Sky Survey
Repeat spectroscopic observations from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) provide an unprecedented opportunity to study the properties of thousands of quasar absorption lines (QALs) in the time domain. Systems of QALs have proven to be one of the most sensitive and unbiased …
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Missing channel reconstruction for sloan digital sky survey images using linear models and generative adversarial networks
The Sloan Digital Sky Survey (SDSS) dataset, one of the largest astronomical surveys, suffers from noise and missing information in some of the image channels. This thesis implements two methods—the linear model and the deep learning model—on 12,730 SDSS images for missing channel re- construction. …
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Galactic Flood Fill Segmentation and Machine Learning Redshift Estimation
… datasets are so large due to high volume modern surveys that automated analysis techniques are now required. Redshift is a prime example of an expensive measurement that is a candidate for automation. The Sloan Digital Sky Survey alone imaged more than 1 billion objects in 9 years, but only …
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The core collapse supernova rate in the sdss-ii supernova survey
<p>The Sloan Digital Sky Survey II Supernova Survey (SDSS-II SN), though designed as a type Ia supernova search for cosmology, also discovered a large sample of core collapse supernovae (CCSN). I use the SDSS-II SN data to measure the volumetric CCSN rate in the redshift range (0.03 < z < 0.09), …
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Properties of Galaxies Detected in Emission and Absorption with Background Quasars
… of galaxies at other epochs. The role of the Sloan Digital Sky Survey has been paramount in this study. Presented here are two sets of data: high metallicity DLA and sub-DLA absorption systems at z>0.4 and quasar-galaxy pairs selected in emission from the Sloan Digital Sky Survey at z0.4 …
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Deep learning for supernovae detection
In future astronomical sky surveys it will be humanly impossible to classify the tens of thousands of candidate transients detected per night. This thesis explores the potential of using state-of-the-art machine learning algorithms to handle this burden more accurately and quickly than trained …
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Spectroscopy of white dwarf stars observed by HETDEX.
… photosphere and a degenerate core. Large-scale surveys, such as the Sloan Digital Sky Survey, have spectroscopically observed more than 40,000 white dwarfs to date, providing a large sample to be used in the evaluation of these theoretical models. We use spectral data of white dwarf stars found …
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Classification of Stars from Redshifted Stellar Spectra utilizing Machine Learning
… of stellar spectra but few that involve the Sloan Digital Sky Survey (SDSS). Stellar spectra from the SDSS are applied to standard classification methods such as K-Nearest Neighbors, Random Forest, and Support Vector Machine to automatically classify the spectra. Stellar spectra are high …
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Boosting (in)direct detection of dark matter
… the dark matter velocity distribution. I use the Sloan Digital Sky Survey to obtain the first empirical velocity distribution of dark matter, which weakens the expected direct detection limits by up to an order of magnitude at masses </~ 10 GeV. Finally, I expand the weakly interacting dark matter …
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Characterization of the Galactic White Dwarf Population in the Next Generation Virgo Cluster Survey
… data from the Next Generation Virgo Cluster Survey (NGVS) and ultravoilet data from the GALEX Ultraviolet Virgo Cluster Survey (GUViCS) to select candidates which may belong to this population of recently formed halo white dwarfs. A colour selection was used to separate white dwarfs from QSOs …
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Quantitative analysis of 3-arm spiral galaxies
… Most of our work involved images taken from the Sloan Digital Sky Survey (SDSS), supplemented with high-resolution Hubble Space Telescope (HST) observations. This allowed us to study the morphological demographics of our sample, for both the internal structure and arm symmetry. The HST images …
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The Optical Variability of Quasars as Seen by SDSS
… confirmed quasars recently assembled by the Sloan Digital Sky Survey (SDSS). This database is an excellent data set to study quasar variability, and includes 9,000 well-sampled light curves from Stripe 82 and a 25,000-object two-epoch sample from the northern Galactic sky. I show that the …
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Lenticular galaxies - the one in the middle
… A sample of lenticular galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G) using the Spitzer Space Telescope along with Sloan Digital Sky Survey (SDSS) was used for this project to study molecular gas properties as well morphologies associated with dust where molecular gas is …
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Search for Ultra-faint Milky Way Satellites
… known satellite galaxies were discovered by the Sloan Digital Sky Survey whose survey footprint mainly focused on the northern Galactic pole region. Subsequent surveys to map the southern sky were thus required for an unbiased observational assessment of the standard cosmological model. This …
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Search for Ultra-faint Milky Way Satellites
… known satellite galaxies were discovered by the Sloan Digital Sky Survey whose survey footprint mainly focused on the northern Galactic pole region. Subsequent surveys to map the southern sky were thus required for an unbiased observational assessment of the standard cosmological model. This …
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Modeling large scale structure from photometric surveys
… selected from the seventh data release of the Sloan Digital Sky Survey. The galaxy sample was selected with r-band apparent magnitudes between 17 and 21; and we update the flag criteria to select a clean galaxy catalog and detail specific tests that we perform to characterize systematic …
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Constraints on early-type galaxy structure from spectroscopically selected gravitational lenses
… describes all aspects of a unique spectroscopic survey for strong galaxy-galaxy gravitational lenses: motivation, candidate selection, ground-based spectroscopic follow-up, Hubble Space Telescope imaging, data analysis, and results on the radial density profile of the lens galaxies. The lens …
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