자료유형 | 학위논문 |
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서명/저자사항 | Advancements in Very-High-Energy Gamma-Ray Astronomy with Applications to the Study of Cosmic Rays. |
개인저자 | Petrashyk, Andrii. |
단체저자명 | Columbia University. Physics. |
발행사항 | [S.l.]: Columbia University., 2019. |
발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
형태사항 | 208 p. |
기본자료 저록 | Dissertations Abstracts International 81-02B. Dissertation Abstract International |
ISBN | 9781085689298 |
학위논문주기 | Thesis (Ph.D.)--Columbia University, 2019. |
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Source: Dissertations Abstracts International, Volume: 81-02, Section: B.
Advisor: Humensky, Thomas B. |
이용제한사항 | This item must not be sold to any third party vendors. |
요약 | This work aims to contribute to the study of the origins of cosmic rays, and broadly, to the advancement of both data analysis methods and instrumentation for very-high-energy 款-ray astronomy. First, reviewing the state of 款-ray astronomy, we show how gains in sensitivity can be achieved through sophisticated data analyses and improved instrumental designs. We then develop such an improved analysis method for the Very Energetic Radiation Imaging Telescope Array System (VERITAS) by combining Image Template Method (ITM) with Boosted Decision Trees (BDT), and study its performance, attaining a 30-50% improvement in integral sensitivity over the instrument's standard analysis. Systematic issues in spectral reconstruction that the analysis displays are resolved satisfactorily by imposing a more stringent condition on the selection of its energy threshold. We employ the newly developed analysis to measure the 款-ray energy spectrum of the starburst galaxy M82, and combining our result with a measurement from the Fermi Large Area Telescope (Fermi-LAT), we find that a single power law fits the spectrum well between 100 GeV and 10 TeV, with no evidence for a spectral break or a cutoff. We conclude that this is in line with the current understanding that M82 is not a good proton calorimeter. Finally, we detail the design, implementation, and performance of the optical alignment system of the prototypeSchwarzschild-Couder Telescope (pSCT) for the Cherenkov Telescope Array (CTA), a novel two-mirror design that addresses many shortcomings of current instruments. |
일반주제명 | Astrophysics. Astronomy. |
언어 | 영어 |
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