Date of Award
Master of Science (MS)
Physics and Astronomy
Type Ia supernovae (SNe Ia), otherwise known as thermonuclear supernovae, are objects in astronomy whose importance cannot be understated. They are essential to describing galaxy chemical evolution and abundances, and are the primary producers of iron and other iron group elements in the Universe. They inject energy into the interstellar medium (ISM), triggering bursts of star formation and effecting the kinematics of the ISM. Most importantly, the homogeneity between ’normal’ SNe Ia light curve evolution and peak brightness after empirical corrections are applied has allowed these objects to be used in cosmology as high redshift distance indicators, leading to the discovery of the acceleration of the expanding Universe. Despite the importance of these objects, the progenitor systems and explosion mechanism leading up to a SN Ia explosion are not well understood. Observations in the gamma-ray regime will be able to probe the inner mechanisms of these events, providing valuable information on how these objects detonate and other fundamental physical properties. Prospective gamma-ray detectors focused on SN Ia physics have been proposed but understanding SN Ia rates are crucial to the future of these missions. In particular, local rates are useful to discern how many SNe Ia are expected to occur nearby within the average duration of a gamma-ray observatory. Multiple methods have been used to derive the SN Ia rate at the local and cosmic level, but they often suffer from observational bias in that they are extrapolated from surveys that target pre-selected galaxies or specific areas of the sky. These rates may not provide an accurate description of the local Universe based on the actual distribution of galaxies and their physical properties. In this work, we aim to describe the local SN Ia rate by applying a rate-size relation to all of the locally (≤100 Mpc) cataloged galaxies. We calculate the SN rate for each galaxy based on its B-band luminosity and determine the probability of a SN Ia event over the span of ten years, or the typical duration of a gamma-ray mission. We simulate SNe Ia within the local Universe and investigate the rate of events based on the average number of SNe Ia for each run of the simulation. We find that approximately 89 SNe Ia per year are expected to occur within 100 Mpc. We also investigate our SNe rates as a function of distance and find that, in general, the frequency of SNe Ia over distance follows a trendline of ad^3 where d is the distance and a is a scale factor added to fit to the data.
Dunn, Brianne, "Estimating Thermonuclear Supernovae Rates in the Local Universe" (2021). All Theses. 3605.