Date of Degree
PhD (Doctor of Philosophy)
Kaaret, Philip E.
First Committee Member
Spangler, Steven R.
Second Committee Member
Lang, Cornelia C.
Third Committee Member
Gayley, Kenneth G.
Fourth Committee Member
Finley, John P.
The constant flux of cosmic rays that bombard Earth from within our own galaxy are understood to come from both shell-type supernova remnants and pulsar wind nebulae (PWNe). Multiwavelength study of these objects can help us to understand what types of particles are accelerated, and gamma-ray emission is key to understanding the highest energy cosmic rays. In this thesis, I analyze and interpret observations made with the Very Energetic Radiation Imaging Telescope Array System (VERITAS), a gamma-ray telescope located in Southern Arizona.
LS 5039 and HESS J1825-137 occupy the same field of view on the sky and were observed for about 8 hours with VERITAS. LS 5039 is a gamma-ray binary, and the observations supports theories that the compact object hosts a PWN which is continuously interacting with the nearby star. HESS J1825-137 is a very extended PWN with an extent of diameter greater than 1 degree on the sky. Using the VERITAS observations, I am able to measure the radial profile and compare the gamma-ray luminosity to other PWN.
DA 495, a "Crab-like" PWN with unusually strong magnetic fields, was observed for about 70 hours with VERITAS. In this study, results are combined with radio and X-ray spectral information to allow for detailed astrophysical modeling of the region. This broadband spectral modeling places constraints on the properties of the particle population in this PWN and allows for both leptonic and hadronic emission scenarios to be evaluated. Hadronic scenarios instil doubt on the pure PWN interpretation and favor a previously undetected shell-type remnant being present.
gamma-ray astronomy, particle acceleration, pulsar wind nebula, supernova remnants
xi, 107 pages
Includes bibliographical references (pages 96-107).
Copyright © 2019 Patrick Dean Wilcox
Wilcox, Patrick Dean. "Observations of supernova remnants at very high energies with VERITAS." PhD (Doctor of Philosophy) thesis, University of Iowa, 2019.