Matching Items (331)
Description
3D models of white dwarf collisions are used to assess the likelihood of double-degenerate mergers as progenitors for Type Ia supernovae (henceforth SNIa) and to identify observational signatures of double-degenerate collisions. Observations of individual SNIa, SNIa rates in different galaxy types, and double white dwarf binary systems suggest that mergers or collisions between two white dwarfs play a role in the overall SNIa population. Given the possibility of two progenitor systems (single-degenerate and double-degenerate), the sample of SNIa used in cosmological calcula- tions needs to be carefully examined. To improve calculations of cosmological parameters, the development of calibrated diagnostics for double-degenerate progenitor SNIa is essential. Head-on white dwarf collision simulations are used to provide an upper limit on the Ni-56 production in white dwarf collisions. In chapter II, I explore zero impact parameter collisions of white dwarfs using the Eulerian grid code FLASH. The initial 1D white dwarf profiles are created assuming hydrostatic equilibrium and a uniform composition of 50% C-12 and 50% O-16. The masses range from 0.64 to 0.81 solar masses and have an isothermal temperature of 10^7 K. I map these 1D models onto a 3D grid, where the dimensions of the grid are each eight times the white dwarf radius, and the dwarfs are initially placed four white dwarf radii apart (center to center). To provide insight into a larger range of physical possibilities, I also model non-zero impact parameter white dwarf collisions (Chapter III). Although head-on white dwarf collisions provide an upper limit on Ni-56 production, non-zero impact parameter collisions provide insight into a wider range of physical scenarios. The initial conditions (box size, initial separation, composition, and initial temperature) are identical to those used for the head-on collisions (Chapter II) for the same range of masses. For each mass pair- ing, collision simulations are carried out at impact parameters b=1 and b=2 (grazing). Finally, I will address future work to be performed (Chapter IV).
ContributorsHawley, Wendy Phyllis (Author) / Timmes, Frank (Thesis advisor) / Young, Patrick (Committee member) / Starrfield, Sumner (Committee member) / Fouch, Matt (Committee member) / Patience, Jennifer (Committee member) / Arizona State University (Publisher)
Created2012
Description
As the detection of planets become commonplace around our neighboring stars, scientists can now begin exploring their possible properties and habitability. Using statistical analysis I determine a true range of elemental compositions amongst local stars and how this variation could affect possible planetary systems. Through calculating and analyzing the variation in elemental abundances of nearby stars, the actual range in stellar abundances can be determined using statistical methods. This research emphasizes the diversity of stellar elemental abundances and how that could affect the environment from which planets form. An intrinsic variation has been found to exist for almost all of the elements studied by most abundance-finding groups. Specifically, this research determines abundances for a set of 458 F, G, and K stars from spectroscopic planet hunting surveys for 27 elements, including: C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, La, Ce, Nd, Eu, and Hf. Abundances of the elements in many known exosolar planet host stars are calculated for the purpose investigating new ways to visualize how stellar abundances could affect planetary systems, planetary formation, and mineralogy. I explore the Mg/Si and C/O ratios as well as place these abundances on ternary diagrams with Fe. Lastly, I emphasize the unusual stellar abundance of τ Ceti. τ Ceti is measured to have 5 planets of Super-Earth masses orbiting in near habitable zone distances. Spectroscopic analysis finds that the Mg/Si ratio is extremely high (~2) for this star, which could lead to alterations in planetary properties. τ Ceti's low metallicity and oxygen abundance account for a change in the location of the traditional habitable zone, which helps clarify a new definition of habitable planets.
ContributorsPagano, Michael (Author) / Young, Patrick (Thesis advisor) / Shim, Sang-Heon (Committee member) / Patience, Jennifer (Committee member) / Desch, Steven (Committee member) / Anbar, Ariel (Committee member) / Arizona State University (Publisher)
Created2014
Description
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 literature sources for 46 elements across 2836 stars in the solar neighborhood, within 150 pc of the Sun, to produce the Hypatia Catalog. I analyze the variability of the spread in abundance measurements reported for the same star by different surveys, the corresponding stellar atmosphere parameters adopted by various abundance determination methods, and the effect of normalizing all abundances to the same solar scale. The resulting abundance ratios [X/Fe] as a function of [Fe/H] are consistent with stellar nucleosynthetic processes and known Galactic thin-disk trends. I analyze the element abundances for 204 known exoplanet host-stars. In general, I find that exoplanet host-stars are not enriched more than the surrounding population of stars, with the exception of iron. I examine the stellar abundances with respect to both stellar and planetary physical properties, such as orbital period, eccentricity, planetary mass, stellar mass, and stellar color. My data confirms that exoplanet hosts are enriched in [Fe/H] but not in the refractory elements, per the self-enrichment theory for stellar composition. Lastly, I apply the Hypatia Catalog to the Catalog of Potentially Habitable Stellar Systems in order to investigate the abundances in the 1224 overlapping stars. By looking at stars similar to the Sun with respect to six bio-essential elements, I created maps that have located two ``habitability windows'' on the sky: (20.6hr, -4.8deg) and (22.6hr, -48.5deg). These windows may be of use in future targeted or beamed searches.
ContributorsHinkel, Natalie R (Author) / Timmes, Frank X (Thesis advisor) / Anbar, Ariel (Committee member) / Patience, Jennifer (Committee member) / Shumway, John (Committee member) / Young, Patrick (Committee member) / Arizona State University (Publisher)
Created2012
Description
The formation of the firsts stars some 100-300 Myr after the Big Bang marked the end of the cosmic darks ages and created the elemental building blocks of not only rocky planets but eventually us. Understanding their formation, lifetimes, and contributions to the evolution of our universe is one of the current frontiers in astronomy and astrophysics.
In this work I present an improved model for following the formation of Pop III stars, their effects on early galaxy evolution, and how we might search for them. I make use of a new subgrid model of turbulent mixing to accurately follow the time scales required to mix supernova (SN) ejecta -- enriched with heavy elements -- into the pristine gas. I implement this model within a large-scale cosmological simulation and follow the fraction of gas with metallicity below a critical value marking the boundary between Pop III and metal enriched Population II (Pop II) star formation. I demonstrate that accounting for subgrid mixing results in a Pop III stars formation rate that is 2-3 times higher than standard models with the same physical resolution.
I also implement and track a new "Primordial metals" (PM) scalar that tracks the metals generated by Pop III SNe. These metals are taken up by second generation stars and likely result in a subclass of carbon-enhanced, metal-poor (CEMP) stars. By tracking both regular metals and PM, I can model, in post-processing, the elemental abundances of simulation stars. I find good agreement between observations of CEMP-no Milky Way halo stars and second generation stars within the simulation when assuming the first stars had a typical mass of 60 M☉, providing clues as to the Pop III initial mass function.
In this work I present an improved model for following the formation of Pop III stars, their effects on early galaxy evolution, and how we might search for them. I make use of a new subgrid model of turbulent mixing to accurately follow the time scales required to mix supernova (SN) ejecta -- enriched with heavy elements -- into the pristine gas. I implement this model within a large-scale cosmological simulation and follow the fraction of gas with metallicity below a critical value marking the boundary between Pop III and metal enriched Population II (Pop II) star formation. I demonstrate that accounting for subgrid mixing results in a Pop III stars formation rate that is 2-3 times higher than standard models with the same physical resolution.
I also implement and track a new "Primordial metals" (PM) scalar that tracks the metals generated by Pop III SNe. These metals are taken up by second generation stars and likely result in a subclass of carbon-enhanced, metal-poor (CEMP) stars. By tracking both regular metals and PM, I can model, in post-processing, the elemental abundances of simulation stars. I find good agreement between observations of CEMP-no Milky Way halo stars and second generation stars within the simulation when assuming the first stars had a typical mass of 60 M☉, providing clues as to the Pop III initial mass function.
ContributorsSarmento, Richard John (Author) / Scannapieco, Evan (Thesis advisor) / Windhorst, Rogier (Committee member) / Young, Patrick (Committee member) / Timmes, Frank (Committee member) / Patience, Jennifer (Committee member) / Arizona State University (Publisher)
Created2018
Description
Our lives are full of possibilities but also of self-imposed limitations. For some, finding their purpose in life and their place in the society is instinctive, but for many of us it requires a deliberate search. For the latter, self-discovery is a journey; an intentional path of many turns and twists, ups and downs, some surprises. It requires a person to slow down and assess oneself. What has been so far, what is right there on the surface, what is hidden deep down, and what is it that one strives for? Now, imagine narrowing down that path even more, and try to answer the question: Who am I as an artist?
ContributorsBlasko, Tanja (Author) / McMahon, Jeff (Thesis director) / Bowditch, Rachel (Committee member) / School of Film, Dance and Theatre (Contributor) / School of Art (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
How do you convey what’s interesting and important to you as an artist in a digital world of constantly shifting attentions? For many young creatives, the answer is original characters, or OCs. An OC is a character that an artist creates for personal enjoyment, whether based on an already existing story or world, or completely from their own imagination.
As creations made for purely personal interests, OCs are an excellent elevator pitch to talk one creative to another, opening up opportunities for connection in a world where communication is at our fingertips but personal connection is increasingly harder to make. OCs encourage meaningful interaction by offering themselves as muses, avatars, and story pieces, and so much more, where artists can have their characters interact with other creatives through many different avenues such as art-making, table top games, or word of mouth.
In this thesis, I explore the worlds and aesthetics of many creators and their original characters through qualitative research and collaborative art-making. I begin with a short survey of my creative peers, asking general questions about their characters and thoughts on OCs, then move to sketching characters from various creators. I focus my research to a group of seven core creators and their characters, whom I interview and work closely with in order to create a series of seven final paintings of their original characters.
As creations made for purely personal interests, OCs are an excellent elevator pitch to talk one creative to another, opening up opportunities for connection in a world where communication is at our fingertips but personal connection is increasingly harder to make. OCs encourage meaningful interaction by offering themselves as muses, avatars, and story pieces, and so much more, where artists can have their characters interact with other creatives through many different avenues such as art-making, table top games, or word of mouth.
In this thesis, I explore the worlds and aesthetics of many creators and their original characters through qualitative research and collaborative art-making. I begin with a short survey of my creative peers, asking general questions about their characters and thoughts on OCs, then move to sketching characters from various creators. I focus my research to a group of seven core creators and their characters, whom I interview and work closely with in order to create a series of seven final paintings of their original characters.
ContributorsCote, Jacqueline (Author) / Button, Melissa M (Thesis director) / Dove-Viebahn, Aviva (Committee member) / School of Art (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The Beauty Within is a ceramics show displaying human body anatomy, which seeks to bridge aspects of my biological sciences major in the School of Life Sciences with aspects of my studio art minor in the Herberger Institute for Design and the Arts. My goal in creating the show was to change the opinion of people on human body organs from unease to admiration by recreating these organs in an artistic light. By stylizing the construction of the pieces and bringing in the contemporary form of art \u2014 makeup art \u2014 I hoped to bring a new light to the pieces and highlight the beauty within the human body. By leaving the pieces partly unfinished I further hoped to draw attention to the natural beauty within the pieces regardless of the makeup that covers them. By holding the show in the human anatomy lab room on campus and having both animal and human organs on display I was able to create that sense of disgust toward the organs in the viewers. The beauty of my created pieces was then directly contrasted with the disgust felt about the real organs by displaying each of my pieces next to a real organ. The reactions of the viewers reflected a change in view from the actual organs to my re-created organs, and therefore the goal of the show was achieved.
ContributorsThomas, Brandon Lee (Author) / Weiser, Kurt (Thesis director) / Chung, Samuel (Committee member) / School of Art (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
I saw a Dove ad called "Real Beauty Sketches" where a group of women described themselves to a sketch artist, and then a complete stranger described them to the same artist. By the end of the ad, it's apparent that the women, when describing themselves, were very critical of all their features. When total strangers described them the resulting portrait was more beautiful to the women. The take-away from the campaign was that others see more beauty in you than you do in yourself. I explored that idea through my thesis. My aim in this project was to learn to see the beauty in myself through personal artistic expression. I completed a series of self-portraits; for about four months straight I drew one portrait of myself every single day. I also recorded my thoughts in a diary entry as I drew my portrait, hoping to capture my emotions and moods during that day. The resulting outcome of my creative project is twofold. The physical outcome is about 100 self-portraits and daily diary entries that represent the creative thesis project I pursued. The second outcome cannot be physically seen. I have discovered more about myself in four months than I have in twenty years. I have begun to see myself differently, and positively. This thesis project turned into a journey of self-exploration, and I'm looking forward to what the future holds for me.
ContributorsRao, Rachana Sai (Author) / Hood, Mary (Thesis director) / Button, Melissa (Committee member) / School of Art (Contributor) / W. P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Dressler Makes Things (DMT), as a thesis project, explores the viability of DMT as a monetized blog. DMT is a life improvement blog with a focus on cooking. Its blog niche sits between nostalgic, sensory food blogs and professional, actionable life improvement blogs. Because blogs that bridge this gap are rare, DMT aims to fill this need by making cooking easy, affordable, and attainable for anyone, but particularly females in their early twenties. This thesis explores marketing topics like brand, blog niche, unique value proposition, current viewers, and user personas, as well as information about the current blogging environment and an analysis of relevant competitors. It also develops marketing objectives for DMT, as well as positioning, conversion, referral, content promotion, and partnership strategies to reach these goals. Finally, it discusses distribution, pricing, and promotional tactics, as well as an operational plan and financial projections.
ContributorsParsons, Dressler Eileen (Author) / Gray, Nancy (Thesis director) / Bitter, Gary (Committee member) / School of Art (Contributor) / Department of Marketing (Contributor) / W. P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
For my creative project, I began an art press that produces small-run vinyl records and artist's books. Initially, the venture began as a means to circumvent record pressing facilities as a vinyl record-cutting service. By the end of this project, the focus shifted to encompass more visual art products than just vinyl records. The project began with vinyl records because I saw a need in the market; in the past decade, the industry has grown dramatically, but the dozen record pressing plants in the country cannot keep up with the demand. Because record pressing companies prioritize large orders, it is difficult for many small bands and independent record labels to produce work on this medium. This is due to the long lead times, high prices, and large minimum order sizes. I located a man in Germany, who invented a machine that makes high-quality, lathe-cut records. I named the project Blushing Soup, as homage to my father, who passed during my first semester of college. It is through his passing that I was able to secure funds to pursue this venture. I brought on a partner, who was more familiar with art and audio recording than myself. In the summer of 2015, we met with this inventor to learn how to use his machine. By October of 2015, a machine of our own had arrived. In early November, Blushing Soup won a grant from the Scottsdale Museum of Contemporary Art. During this time, we released two vinyl records for local bands. For a culminating project, I coordinated a Record Store Day compilation album consisting of six bands featuring. After securing all of the music, the machine started having problems, which forced me to cancel this release. Recognizing the delicacy of the machine, prompted a shift in the aim of Blushing Soup. During this process, I started learning printmaking processes, and I realized that Blushing Soup could function as more than a record cutting service; we could be an art press. In the last few month of this project, I started making artist's books. By the end of April 2016, Blushing Soup will have released vinyl records for two bands, as well as produced four handmade books. This creative project centered around the process of creating art through lathe cutting and printmaking; the objective was not to maximize profits but rather refocus the consumption of art (in a sustainable practice).
ContributorsStringer, Shelby Manning (Author) / Essig, Linda (Thesis director) / Peck, Sidnee (Committee member) / School of Art (Contributor) / Department of English (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05