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.
Results
Showing 1 to 20 of 20 for “"sky surveys"”.
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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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Galaxy classification with deep convolutional neural networks
… using digital images captured from sky surveys to determine the galaxy morphological classes, is of great interest to astronomy researchers. Conventional methods rely heavily on a few handcrafted morphological features while popular feature extraction methods that developed for …
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Hierarchical Classification of Variable Stars Using Neural Networks
… With the proliferation of large-scale sky surveys that generate over 20 Terabytes of light-curve observations every day, automated methods are necessary to reduce manual efforts when classifying variable stars. To automate such classification, astronomers have developed various machine …
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Beamforming Techniques and Interference Mitigation Using a Multiple Feed Array for Radio Astronomy
… possible, while at the same time enabling rapid sky surveys. A phased array feed was designed and simulated, and sensitivity optimization was performed on the array feed. It was shown that higher sensitivity can be achieved using a 7-element phased array feed than with a conventional waveguide …
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Analysis and Application of Automated Methods for Detecting Pulsars in the Green Bank Telescope 350MHz Drift-Scan Survey
… of the process of detecting pulsars from radio sky surveys remains a largely manual task. The visual inspection of data in order to detect and validate potential pulsar candidates is by far the most time consuming portion of the overall process. Coupled with the fact that well over a Petabyte of …
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The Optical Variability of Quasars as Seen by SDSS
… 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 damped random …
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Optical and X-ray studies of newly discovered flare stars
… the ROSAT Wide Field Camera (WFC) and EUVE all-sky surveys. During a total photometric monitoring time of 121 hrs on 6 new stars, there were 54 separate optical flares recorded, including a dramatic AU = 3.8 mag flare, emitting an energy in the U-band of Eu lx 10 erg. Three other flares had AU > …
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A survey of cataclysmic variables from the Edinburgh-Cape Blue object survey
… and includes a general review of blue star sky surveys, a detailed discussion of the selection techniques, the present status of the survey, and follow-up photometry and spectroscopy of the cataclysmic variable stars (GVs) found by the survey. Because of the north-south imbalance in the …
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Characterization of Radio Emission from Young Stellar Objects
… Novel results are presented from large surveys at radio wavelengths, revealing new detections and characterization of the emission from YSOs, as well as providing constraints on such emission from planetary-mass objects. Results from numerous low-frequency projects were studied, …
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Core-collapse supernovae in the great survey era
A new class of wide-field, repeated-scan optical sky surveys, such as LSST, is coming online, and will map the sky in the time domain with unprecedented depth, completeness, and dynamic range. A main science goal of LSST is to detect Type Ia supernovae, but the survey will also revolutionize our …
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Observation and Modelling of Meter-Class Earth impacting Asteroids
… and a brief description of the software ClearSky used to implement these projects.
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Discovering and characterising compact mergers in wide-field surveys
… and intrinsically faint transients with all-sky survey telescopes. Such a simulation has been used to constrain the volumetric rate of AT2017gfo-like transients in the local universe, with the results being consistent with other optically-derived rates estimates and rate of binary neutron …
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Weighing the Milky Way While Exploring Dynamical Disequilibrium
… assumed. However, many recent big telescopes and sky surveys have provided evidence against the equilibrium assumption, with the most iconic feature being the spiral patterns of number counts, mean radial velocity and mean azimuthal velocity in the vertical phase space. Under such a context, while …
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THE CEPHEIDS OF M33: DISTANCE AND METALLICITY EFFECTS THROUGH SLOAN FILTERS
… filters. With the advent of large-scale sky surveys using Sloan-band filters, Cepheid studies in Sloan filters will become more prevalent. It is important that there exist baseline Leavitt Laws against which future work can be compared. This thesis aims to provide Leavitt Laws in Sloan …
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Identifying intervening absorption systems for use as cosmological probes
… being one of the most luminous objects in the sky can act as cosmological probes for analyzing not only the large-scale structures (LSSs) in the universe, but also to trace the metal absorption systems by probing the gas content (Zibetti et at., 2005; Ménard et at., 2005) that lie on the …
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Tracer populations in the local group
… of a variable catalogue from the Sloan Digital Sky Survey Stripe 82 dataset and then use the catalogue to select a high-quality set of RR Lyrae stars. Analysing the distribution of the RR Lyraes reveals three significant substructures in the Milky Way halo: the Hercules-Aquila Cloud and the …
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Multiwavelength studies of classical novae
… of the progenitor. In the era of large all-sky surveys, such as the All-Sky Automated Survey for Supernovae and eventually the Large Synoptic Survey Telescope which have been and are ex- pected to find a large number of optical transients and classical novae, similar multiwavelength …
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The Bayesian Global Sky Model (B-GSM)
… model be available for the low frequency sky. In this thesis, we present a new low frequency global model of the diffuse radio sky, the Bayesian Global Sky Model (B-GSM). The novel Bayesian framework of B-GSM aims to address the limitations of previous sky models, notably the Global Sky …
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Investigation of the Progenitors and Outbursts of Classical and Recurrent Novae
… one outburst in archival plates or large sample sky surveys such as SMEI (see below).By introducing the high cadence full-sky space-based observational archive of the Solar Mass Ejection Imager (SMEI) which operated on the Coriolis satellite from 2003-2011, we derived light curves of one Mira (O …
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Exploring the nature and origins of low luminosity type IIP supernovae
… the introduction of much deeper multi-band sky surveys as well as the continued work of instruments such as HST will greatly benefit our understanding of these SNe and their progenitors.</p>