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ASU Electronic Theses and Dissertations


This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.


Status
  • Public
Subject
Date Range
2010 2019


Gamma-ray burst observations provide a great opportunity for cosmography in high redshift. Some tight correlations between different physical properties of GRBs are discovered and used for cosmography. However, data selection, assumptions, systematic uncertainty and some other issues affect most of them. Most importantly, until the physical origin of a relation is understood, one should be cautious to employ the relation to utilize Gamma ray bursts for cosmography. In the first part of this dissertation, I use Liang-Zhang correlation to constrain ¦« Cold Dark Matter standard cosmology and a particular class of brane cosmology (brane-induced gravity model). With the most probable …

Contributors
Behkam, Razieh, Windhorst, Rogier, Rhoads, James, et al.
Created Date
2010

Type Ia supernovae are important, but mysterious cosmological tools. Their standard brightnesses have enabled cosmologists to measure extreme distances and to discover dark energy. However, the nature of their progenitor mechanisms remains elusive, with many competing models offering only partial clues to their origins. Here, type Ia supernova delay times are explored using analytical models. Combined with a new observation technique, this model places new constraints on the characteristic time delay between the formation of stars and the first type Ia supernovae. This derived delay time (500 million years) implies low-mass companions for single degenerate progenitor scenarios. In the latter …

Contributors
Raskin, Cody, Scannapieco, Evan, Rhoads, James, et al.
Created Date
2011

Galaxies with strong Lyman-alpha (Lya) emission line (also called Lya galaxies or emitters) offer an unique probe of the epoch of reionization - one of the important phases when most of the neutral hydrogen in the universe was ionized. In addition, Lya galaxies at high redshifts are a powerful tool to study low-mass galaxy formation. Since current observations suggest that the reionization is complete by redshift z~ 6, it is therefore necessary to discover galaxies at z > 6, to use their luminosity function (LF) as a probe of reionization. I found five z = 7.7 candidate Lya galaxies with …

Contributors
Shet Tilvi, Vithal, Malhotra, Sangeeta, Rhoads, James, et al.
Created Date
2011

There are many lines of evidence for anisotropy at all scales in the explosions of core collapse supernovae, e.g. visual inspection of the images of resolved supernova remnants, polarization measurements, velocity profiles, "natal kicks" of neutron stars, or spectroscopic observations of different regions of remnants. Theoretical stability considerations and detailed numerical simulations have shown that Rayleigh-Taylor (RT) instabilities arise in the star after the explosion, which leads to the early fragmentation of parts of the ejecta. The clumps thus created are of interest to a variety of topics, one of them being the formation environment of the solar system. There …

Contributors
Ellinger, Carola I., Young, Patrick A, Desch, Steven J, et al.
Created Date
2011

Most stars form in groups, and these clusters are themselves nestled within larger associations and stellar complexes. It is not yet clear, however, whether stars cluster on preferred size scales within galaxies, or if stellar groupings have a continuous size distribution. I have developed two methods to select stellar groupings across a wide range of size-scales in order to assess trends in the size distribution and other basic properties of stellar groupings. The first method uses visual inspection of color-magnitude and color-color diagrams of clustered stars to assess whether the compact sources within the potential association are coeval, and thus …

Contributors
Kaleida, Catherine Carol, Scowen, Paul A., Windhorst, Rogier A., et al.
Created Date
2011

Using high-resolution three-dimensional adaptive mesh refinement simulations I study the interaction between primordial minihalo, a clump of baryonic and dark matter with a virial temperature below the atomic cooling limit, and a galaxy outflow. In Chapter 2 I concentrate on the formation of molecular coolants and their effect on the evolution of the minihalo gas. Molecular coolants are important since they allow gas to cool below 10000 K. Therefore, I implement a primordial chemistry and cooling network that tracks the evolution and cooling from these species. I show that the shock from the galaxy outflow produces an abundance of coolants …

Contributors
Gray, William James, Scannapieco, Evan, Starrfield, Sumner, et al.
Created Date
2012

The first part of this dissertation presents the implementation of Bayesian statistics with galaxy surface luminosity (SL) prior probabilities to improve the ac- curacy of photometric redshifts. The addition of the SL prior probability helps break the degeneracy of spectro-photometric redshifts (SPZs) between low redshift 4000 A break galaxies and high redshift Lyman break galaxies which are mostly catas- trophic outliers. For a sample of 1138 galaxies with spectroscopic redshifts in the GOODS North and South fields at z < 1.6, the application of the surface luminosity prior reduces the fraction of galaxies with redshift deviation sigma(z) > 0.2 from …

Contributors
Xia, Lifang, Malhotra, Sangeeta, Rhoads, James, et al.
Created Date
2012

The only elements that were made in significant quantity during the Big Bang were hydrogen and helium, and to a lesser extent lithium. Depending on the initial mass of a star, it may eject some or all of the unique, newly formed elements into the interstellar medium. The enriched gas later collapses into new stars, which are able to form heavier elements due to the presence of the new elements. When we observe the abundances in a stellar regions, we are able to glean the astrophysical phenomena that occurred prior to its formation. I compile spectroscopic abundance data from 49 …

Contributors
Hinkel, Natalie R., Timmes, Frank X, Anbar, Ariel, et al.
Created Date
2012

Numerical simulations are very helpful in understanding the physics of the formation of structure and galaxies. However, it is sometimes difficult to interpret model data with respect to observations, partly due to the difficulties and background noise inherent to observation. The goal, here, is to attempt to bridge this gap between simulation and observation by rendering the model output in image format which is then processed by tools commonly used in observational astronomy. Images are synthesized in various filters by folding the output of cosmological simulations of gasdynamics with star-formation and dark matter with the Bruzual- Charlot stellar population synthesis …

Contributors
Morgan, Robert James, Windhorst, Rogier A, Scannapieco, Evan, et al.
Created Date
2012

Understanding the temperature structure of protoplanetary disks (PPDs) is paramount to modeling disk evolution and future planet formation. PPDs around T Tauri stars have two primary heating sources, protostellar irradiation, which depends on the flaring of the disk, and accretional heating as viscous coupling between annuli dissipate energy. I have written a "1.5-D" radiative transfer code to calculate disk temperatures assuming hydrostatic and radiative equilibrium. The model solves for the temperature at all locations simultaneously using Rybicki's method, converges rapidly at high optical depth, and retains full frequency dependence. The likely cause of accretional heating in PPDs is the magnetorotational …

Contributors
Lesniak Iii, Michael V., Desch, Steven J., Scannapieco, Evan, et al.
Created Date
2012