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Arrival Direction Probabilities of Ultra High Energy Cosmic Rays with the Pierre Auger Observatory and Progress Toward an in-situ Cross-calibration of Auger and Telescope Array Surface Detector Stations
- Publication Year :
- 2018
-
Abstract
- The origin and nature of ultra-high energy cosmic rays is an open question in astrophysics since their discovery in the 1960s. Observed energies of these primary particles can approach greater than 10x the center of mass energies achieved at modern collider facilities, and there is presently no consensus for an astrophysical mechanism capable of reaching these energies. The Pierre Auger Observatory is the world's largest cosmic ray observatory, spanning ~3,000 km², dedicated to this problem. After initial acceleration, the primary trajectory from source to solar system is not rectilinear due to magnetic deflection. This dissertation investigates how uncertainties of a modern galactic magnetic field model translate into arrival direction uncertainties for E>50 EeV events using a sensitivity analysis approach. In most cases it's found that uncertainties from B-field model dominate compared to observation systematic errors. Furthermore, the angular extent of 1σ arrival direction contours is found to enclose many potential astrophysical objects, making it difficult to isolate individual sources. Implications for anisotropy studies are also briefly discussed.To enable full-sky coverage, Auger data can be combined with the Telescope Array Project, a similar array operating in the northern hemisphere. In both experiments most data are generated from the surface-detector (SD) array. The TA and Auger experiments use different SD station designs, giving them different sensitivities to extensive air-shower components. We seek to understand and cross-validate these complementary detectors on a hardware level using an in-situ approach to observe the same air showers. We describe the technical details associated with installing the detectors, data acquisition, and analysis of signals for this first stage of the Auger@TA project. Integrated signals are compared to a collection of models, and in general are found to agree with expectations. For a subsample of events air-shower parameters are available, and a sophisticated simulation is run to predict the expected response of the two detectors, which is compared to observed data. These simulations appear to show some discrepancy. Characterizing and understanding the discrepancies will be important for taking full advantage of future planned upgrades to both experiments, especially in the context of atomic composition measurements.
- Subjects :
- Physics
Astrophysics
Subjects
Details
- Language :
- English
- Database :
- OpenDissertations
- Publication Type :
- Dissertation/ Thesis
- Accession number :
- ddu.oai.etd.ohiolink.edu.case1512730856642865