creator Ratliff, Gayle advisor White, Christopher This work describes the Very Energetic Radiation Imaging Telescope Array Systems (VERITAS) observations of the starburst galaxy M82 by documenting the analysis of 231 quality-selected hours of observational data taken between 2008 and 2014. The prototypical starburst galaxy, M82’s high supernova (SN) rate and dense central accumulation of molecular gas make it a promising candidate for studying cosmic ray (CR) acceleration and propagation with the detection of di↵use very high energy (VHE; approximately 100 GeV-100 TeV) !-ray emission. This di↵use emission is predicted to result from proton-proton interactions within the galaxy’s core that produce VHE !-rays through neutral pion decay. This work confirms the results of the initial VERITAS publication covering 137 hours of M82 observations between January 2008 and April 2009, yielding a total of 103.5 excess !-ray-like events (0.007 !/min, 5.7 pre-trial statistical significance) from a deeper exposure of 231 hours of observation. The spectral properties found are in agreement with the original detection within errors ("=2.85 ± 0.39). These results are consistent with paradigms that describe the production of CRs via the conversion of mechanical energy generated in supernovae (SNe). These findings will improve current di↵use emission models by better constraining galaxy parameters and by providing insight into CR proton loss processes and timescales, with further understanding to be gained with the introduction of the Cherenkov Telescope Array (CTA). xiiThis work describes the Very Energetic Radiation Imaging Telescope Array Systems (VERITAS) observations of the starburst galaxy M82 by documenting the analysis of 231 quality-selected hours of observational data taken between 2008 and 2014. The prototypical starburst galaxy, M82’s high supernova (SN) rate and dense central accumulation of molecular gas make it a promising candidate for studying cosmic ray (CR) acceleration and propagation with the detection of di↵use very high energy (VHE; approximately 100 GeV-100 TeV) !-ray emission. This di↵use emission is predicted to result from proton-proton interactions within the galaxy’s core that produce VHE !-rays through neutral pion decay. This work confirms the results of the initial VERITAS publication covering 137 hours of M82 observations between January 2008 and April 2009, yielding a total of 103.5 excess !-ray-like events (0.007 !/min, 5.7 pre-trial statistical significance) from a deeper exposure of 231 hours of observation. The spectral properties found are in agreement with the original detection within errors ("=2.85 ± 0.39). These results are consistent with paradigms that describe the production of CRs via the conversion of mechanical energy generated in supernovae (SNe). These findings will improve current di↵use emission models by better constraining galaxy parameters and by providing insight into CR proton loss processes and timescales, with further understanding to be gained with the introduction of the Cherenkov Telescope Array (CTA). xiiThis work describes the Very Energetic Radiation Imaging Telescope Array Systems (VERITAS) observations of the starburst galaxy M82 by documenting the analysis of 231 quality-selected hours of observational data taken between 2008 and 2014. The prototypical starburst galaxy, M82’s high supernova (SN) rate and dense central accumulation of molecular gas make it a promising candidate for studying cosmic ray (CR) acceleration and propagation with the detection of di↵use very high energy (VHE; approximately 100 GeV-100 TeV) !-ray emission. This di↵use emission is predicted to result from proton-proton interactions within the galaxy’s core that produce VHE !-rays through neutral pion decay. This work confirms the results of the initial VERITAS publication covering 137 hours of M82 observations between January 2008 and April 2009, yielding a total of 103.5 excess !-ray-like events (0.007 !/min, 5.7 pre-trial statistical significance) from a deeper exposure of 231 hours of observation. The spectral properties found are in agreement with the original detection within errors ("=2.85 ± 0.39). These results are consistent with paradigms that describe the production of CRs via the conversion of mechanical energy generated in supernovae (SNe). These findings will improve current di↵use emission models by better constraining galaxy parameters and by providing insight into CR proton loss processes and timescales, with further understanding to be gained with the introduction of the Cherenkov Telescope Array (CTA). xiiThis work describes the Very Energetic Radiation Imaging Telescope Array Systems (VERITAS) observations of the starburst galaxy M82 by documenting the analysis of 231 quality-selected hours of observational data taken between 2008 and 2014. The prototypical starburst galaxy, M82’s high supernova (SN) rate and dense central accumulation of molecular gas make it a promising candidate for studying cosmic ray (CR) acceleration and propagation with the detection of di↵use very high energy (VHE; approximately 100 GeV-100 TeV) !-ray emission. This di↵use emission is predicted to result from proton-proton interactions within the galaxy’s core that produce VHE !-rays through neutral pion decay. This work confirms the results of the initial VERITAS publication covering 137 hours of M82 observations between January 2008 and April 2009, yielding a total of 103.5 excess !-ray-like events (0.007 !/min, 5.7 pre-trial statistical significance) from a deeper exposure of 231 hours of observation. The spectral properties found are in agreement with the original detection within errors ("=2.85 ± 0.39). These results are consistent with paradigms that describe the production of CRs via the conversion of mechanical energy generated in supernovae (SNe). These findings will improve current di↵use emission models by better constraining galaxy parameters and by providing insight into CR proton loss processes and timescales, with further understanding to be gained with the introduction of the Cherenkov Telescope Array (CTA). xiiThis work describes the Very Energetic Radiation Imaging Telescope Array Systems (VERITAS) observations of the starburst galaxy M82 by documenting the analysis of 231 quality-selected hours of observational data taken between 2008 and 2014. The prototypical starburst galaxy, M82’s high supernova (SN) rate and dense central accumulation of molecular gas make it a promising candidate for studying cosmic ray (CR) acceleration and propagation with the detection of di↵use very high energy (VHE; approximately 100 GeV-100 TeV) !-ray emission. This di↵use emission is predicted to result from proton-proton interactions within the galaxy’s core that produce VHE !-rays through neutral pion decay. This work confirms the results of the initial VERITAS publication covering 137 hours of M82 observations between January 2008 and April 2009, yielding a total of 103.5 excess !-ray-like events (0.007 !/min, 5.7 pre-trial statistical significance) from a deeper exposure of 231 hours of observation. The spectral properties found are in agreement with the original detection within errors ("=2.85 ± 0.39). These results are consistent with paradigms that describe the production of CRs via the conversion of mechanical energy generated in supernovae (SNe). These findings will improve current di↵use emission models by better constraining galaxy parameters and by providing insight into CR proton loss processes and timescales, with further understanding to be gained with the introduction of the Cherenkov Telescope Array (CTA). Submitted by Erma Thomas (thomase@iit.edu) on 2016-02-19T22:38:17Z No. of bitstreams: 1 etdadmin_upload_374550.zip: 18071211 bytes, checksum: 7f741f005ff0e87c488743dd30cfef38 (MD5) Made available in DSpace on 2016-02-19T22:38:17Z (GMT). No. of bitstreams: 1 etdadmin_upload_374550.zip: 18071211 bytes, checksum: 7f741f005ff0e87c488743dd30cfef38 (MD5) Previous issue date: 2015-07 Ph.D. in Physics, July 2015 2015 2015-07 http://hdl.handle.net/10560/3734 en Dissertation born digital application/pdf In Copyright http://rightsstatements.org/page/InC/1.0/ Restricted Access PHYS / Physics Illinois Institute of Technology Affiliated department