UVicSpace | Institutional Repository
UVicSpace is the University of Victoria’s open access scholarship and learning repository. It preserves and provides access to the digital scholarly works of UVic faculty, students, staff, and partners. Items in UVicSpace are organized into collections, each belonging to a community.
For more information about depositing items, see the Submission Guidelines.
Recent Submissions
Improving the Skill Development Framework of the Performance Audit and Related Assurance Portfolio for the Office of the Auditor General of BC
(2024) Mosavi, Mercedeh; Lindquist , Evert
A Near Glimpse into a Distant Past: Chemical Analyses of Ancient Milky Way Satellite Galaxies Using High-Resolution Stellar Spectroscopy
(2024) Waller, Fletcher; Venn, Kim; McConnachie, Alan
The least-luminous galaxies ever detected, ultra-faint dwarf (UFD) galaxies, are ancient, metal-poor, dark-matter dominated, and likely represent the floor of the galaxy luminosity function. Their stars preserve the signatures from early chemical evolution, and their dark matter haloes are testing grounds for Lambda-CDM cosmological models. UFDs are subject to tidal interactions with the Milky Way and dwarfs, which visually range from disrupted streams to slightly elongated structures. An extended structure may also be the result of a minor merger of dwarfs. To further our understanding of these extended structures, we examine high-resolution spectra of stars in the outskirts of UFDs. It is expected that signatures of one or just a few early supernovae may be detectable in the chemical abundance patterns of UFD stars. High-resolution spectroscopy of the brightest individual stars allows us to recover these signatures, and piece together the chemodynamical history of these galaxies. We use Gemini/GRACES to obtain high-resolution spectra of potential members in the outskirts of three ultra-faint dwarf (UFD) galaxies: Coma Berenices (>2Rh), Ursa Major I ( 4Rh), and Boötes I ( 4Rh), as well as a new member in the central region of Ursa Major I (where the half-light radius Rh is the radius within which half of the galaxy’s light is contained, measured along the semi-major axis). Targets were selected with a new Bayesian technique which uses Gaia EDR3 photometry and astrometry to determine stellar membership to UFDs. All 5 stars are determined to be members by precision radial velocities and metallicities that confirm their associations with the UFD galaxies. The spectra were also used to measure absorption lines for 10 elements (Na, Mg, K, Ca, Sc, Ti, Cr, Fe, Ni, and Ba), which confirm that the chemical abundances of the outermost stars are in good agreement with stars in the central regions. The abundance ratios and chemical patterns of the stars in Coma Berenices are consistent with contributions from SN Ia, which is unusual for its star formation history and in conflict with previous suggestions that this system evolved chemically from a single core collapse supernova event. The chemistries for all three galaxies are consistent with the outermost stars forming in the central regions, then moving to their current locations through tidal stripping and/or supernova feedback. In Boötes I, however, the lower metallicity and lack of strong carbon enrichment of its outermost stars could also be evidence of a dwarf galaxy merger. To pursue further high-resolution spectroscopic observations of UFD stars, I carried out an internship at the Gemini South telescope Observatory which was timed with the commissioning of the Gemini High Resolution Optical SpecTrograph (GHOST). Target selection, logkeeping, early data reduction, calibration tests and instrument operation tasks were completed during 17 nights of commissioning between June and September 2022. Since commissioning, I performed bug-testing and developed streamlined methods for processing data to work towards completion and refinement of the data reduction
pipeline. With this experience and relative expertise, I worked with the science team towards the goal of publishing our first science results. GHOST has been integrated into the Gemini instrumentation suite and is available for observing proposals
Investigating variations and combinations of geospatial visualizations based on spatial dimensionality of attribute space and reference space
(2024) Jangida, Ayush; Perin, Charles
The effectiveness of information presentation in different forms plays a vital role in our ability to address challenges and make informed decisions. In this thesis, a focus is placed on the visualization of geospatial data. The study begins with the establishment of a systematic framework that categorizes the presentation space consisting of attribute (data) and reference (terrain) space based on their dimensionality. We also introduce MultiDim, an innovative information visualization system capable of rendering a photo-realistic environment in 2D, 2.5D, and 3D reference spaces. To assess its efficacy, we conducted a comprehensive comparative evaluation of user performance (accuracy and completion time) in different dimensions of attribute and reference space. We also conducted a qualitative analysis where we analyzed with the help of an eye-tracker the different strategies that participants adopted while solving tasks. The eye-tracker enabled us to monitor participants' gaze and discern the preferred views for task-solving. Our findings indicate that the dimensionality of the attribute space (data) has negligible effects on accuracy and task completion time. Conversely, the dimensionality of the reference space (terrain) and the presence of distractors within the environment significantly impact both accuracy and task completion time. Notably, our qualitative analysis reveals a preference for views incorporating 3D terrain. These results offer valuable insights for the future design of geospatial visualizations, guiding decisions on the optimal view selection for enhanced task-solving capabilities.
EkTb-9, Triquet Island, N̓úláw̓itx̌v Tribal Area, British Columbia, Canada: A Persistent Place of Human Occupation and Investment in Haíɫzaqv Territory
(2024) Gauvreau, Alisha; Mackie, Quentin; McLaren, Duncan Stewart
Archaeological site EkTb-9, Triquet Island, is situated within the N̓úláw̓itx̌v Tribal area of Haíɫzaqv (Heiltsuk) Nation territory along the outer central coast of British Columbia (BC), Canada. Emerging from the Hakai Ancient Landscapes Archaeology Project, this dissertation explores the 14,000-year record of repeat human occupation and investment at the site. EkTb-9's early post-glacial record is an integral component of the historical ecology of the region as a similar relative sea level has been maintained since the late Pleistocene, supporting access to and repeat occupation of these same areas over millennia. Through collaboration with Haíɫzaqv Nation, oral narratives and language (Haíɫzaqvḷa) are combined with archaeological interpretations and Haíɫzaqv temporal phases are identified for past occupations of the site. This approach considers the intersections of Indigenous knowledge and Western science and the social and political embeddedness of archaeological practice. Collectively, the studies undertaken for this dissertation offer a unique opportunity to explore the theoretical and political importance of observed continuity at a single place of repeated human occupation and investment on the outer NWC of BC; a storied landscape of enduring cultural, economic, ecological, and political significance for Haíɫzaqv Nation.
The Cultic Significance of Wheelmade Terracotta Figures in Late Helladic III C Eleon, Greece
(2024) Galumbeck, Alix; Van Damme, Trevor
Without written records, the evolution of religious practices can only be ascertained from
the evaluation of cultic objects. During the Late Bronze Age (1700-1050 BCE) in mainland
Greece, a significant shift in ritual practice occurred. With the decentralization of Greek society
after the so-called collapse near the end of the Late Bronze Age, it appears that rites previously
restricted to palatial centers were now executed at non-palatial areas. Recently discovered
artifacts consisting of wheelmade terracotta figures excavated at Eleon, a non-palatial site extant
during this period, were evaluated to determine not only their cultic significance but also if
distinct cultic spaces were located at this site. The findings were categorized using a novel
schema including ritual framing and semiotic analysis. Additionally, the objects were correlated
with comparanda from similar sites throughout Mainland Greece, Melos, and Crete to categorize
both their typology and ritual significance. Analysis of the data was performed through the lenses
of cultic continuity, cultic progression, and regional variation. The results reveal that ritual
practices were similar between Eleon and other sites, suggesting that this Post Palatial center had
both cultic objects and shrines.