Doctor of Philosophy (PhD)
Physics and Astronomy
Detection of large amounts of dust in high redshift galaxies suggests that core collapse supernovae (CCSNe) may play a critical role in the dust budget of galaxies in the early universe, when galaxies are only a few hundred million years old. At an age of only 1Gyr, asymptotic giant branch (AGB) stars may not have had the time to become significant dust contributors, leaving CCSNe as an alternative explanation since they quickly evolve and return their material to the surrounding interstellar medium. For the past three years, I have been observing the CCSNe 2007it and 2007od with Gemini, Hubble Space Telescope, and Spitzer Space Telescope in the optical and infrared to look for indicators of dust formation, which appear within the first few years after explosion. The data sets contain large temporal and wavelength coverage, and have led to some unusual and interesting results. In both cases there is evidence for interaction with surrounding circumstellar material (CSM), although neither was classified as a Type IIn. SN 2007it was found to be oxygen rich with a 56Ni mass quite large for a Type IIP, while SN 2007od is oxygen poor with a very low, over two orders of magnitude less, 56Ni mass. Scattered light echoes also seem to be present in both SNe. An estimated 10-4 solar masses of new dust has formed in each SN, consistent with other CCSNe, but still significantly less than needed to account for the amount of dust seen at high redshift. I will discuss these results and their implications for SNe as major dust contributors in the universe.
Document Availability at the Time of Submission
Release the entire work immediately for access worldwide.
Andrews, Jennifer Erin, "A comprehensive study of dust formation and evolution in core collape supernovae" (2011). LSU Doctoral Dissertations. 2868.