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Stellar elemental abundance determination using a Fabry-Pérot interferometer : a thesis submitted in partial fulfilment of the requirements for the degree of Masters [i.e. Master] of Science in Astronomy in the University of Canterbury /Simpson, Jeffrey January 1900 (has links)
Thesis (M. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). "August 3, 2009." Includes bibliographical references (leaves 87-90). Also available via the World Wide Web.
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Investigation of cosmic ray intensity variation at primary rigidity above 1.7 TVLee, Yiu-wa. January 1986 (has links)
Thesis (M.Phil.)--University of Hong Kong, 1987. / Also available in print.
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Medium scale microwave background anisotropy : measurement and detectors design /Goldin, Alexey. January 1999 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Astronomy and Astrophysics. / Includes bibliographical references. Also available on the Internet.
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Probing neutrino properties with the cosmic microwave background /Lopez, Robert E. January 1999 (has links)
Thesis (Ph. D.)--University of Chicago, Department of Physics, December 1999. / Includes bibliographical references. Also available on the Internet.
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Gamma rays and the distribution of cosmic rays in the galaxyUlmer, Melville Paul, January 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 155-158).
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Warping, dust settling and dynamics of protoplanetary disks /O'Sullivan, Mark George. January 2008 (has links)
Thesis (Ph.D.) - University of St Andrews, November 2008.
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Background field effects on particle physicsTinsley, Todd Michael, Dicus, Duane A., January 2005 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Duane A. Dicus. Vita. Includes bibliographical references.
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A Comparison of Maps and Power Spectra Determined from South Pole Telescope and Planck DataHou, Z., Aylor, K., Benson, B. A., Bleem, L. E., Carlstrom, J. E., Chang, C. L., Cho, H-M., Chown, R., Crawford, T. M., Crites, A. T., de Haan, T., Dobbs, M. A., Everett, W. B., Follin, B., George, E. M., Halverson, N. W., Harrington, N. L., Holder, G. P., Holzapfel, W. L., Hrubes, J. D., Keisler, R., Knox, L., Lee, A. T., Leitch, E. M., Luong-Van, D., Marrone, D. P., McMahon, J. J., Meyer, S. S., Millea, M., Mocanu, L. M., Mohr, J. J., Natoli, T., Omori, Y., Padin, S., Pryke, C., Reichardt, C. L., Ruhl, J. E., Sayre, J. T., Schaffer, K. K., Shirokoff, E., Staniszewski, Z., Stark, A. A., Story, K. T., Vanderlinde, K., Vieira, J. D., Williamson, R. 17 January 2018 (has links)
We study the consistency of 150 GHz data from the South Pole Telescope (SPT) and 143 GHz data from the Planck satellite over the patch of sky covered by the SPT-SZ survey. We first visually compare the maps and find that the residuals appear consistent with noise after accounting for differences in angular resolution and filtering. We then calculate (1) the cross-spectrum between two independent halves of SPT data, (2) the cross-spectrum between two independent halves of Planck data, and (3) the cross-spectrum between SPT and Planck data. We find that the three cross-spectra are well fit (PTE = 0.30) by the null hypothesis in which both experiments have measured the same sky map up to a single free calibration parameter-i.e., we find no evidence for systematic errors in either data set. As a by-product, we improve the precision of the SPT calibration by nearly an order of magnitude, from 2.6% to 0.3% in power. Finally, we compare all three cross-spectra to the full-sky Planck power spectrum and find marginal evidence for differences between the power spectra from the SPT-SZ footprint and the full sky. We model these differences as a power law in spherical harmonic multipole number. The best-fit value of this tilt is consistent among the three cross-spectra in the SPT-SZ footprint, implying that the source of this tilt is a sample variance fluctuation in the SPT-SZ region relative to the full sky. The consistency of cosmological parameters derived from these data sets is discussed in a companion paper.
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Analysis tools for the EMMA experimentRäihä, T. (Tomi) 15 October 2012 (has links)
Abstract
Cosmic rays are energetic particles traversing space that bombard Earth's atmosphere frequently and produce vast particle showers while interacting with air nuclei. The origin and composition of high-energy cosmic rays in the knee region (1015 - 1016 eV) of the cosmic-ray energy spectrum remain unclear despite of novel detection and analysis methods used in various surface and underground experiments. The understanding of the knee has improved from its first detection but still there is notable deviation in results between experiments depending on the used detection methods.
The aim of the underground cosmic-ray experiment EMMA (Experiment with Multi-Muon Array) is to shed more light on the origin of the knee. EMMA is based on the idea to measure the lateral shape of high-energy muon component produced in cosmic-ray initiated particle showers on an event-by-event basis, that is, separately for each shower, offering a unique way to study the composition of cosmic rays in the knee region.
The present work comprises the design, development and implementation of a comprehensive set of analysis tools for the EMMA experiment. It includes the development of the simulation program to generate realistic event data, the track reconstruction program ETANA to reconstruct hits and tracks in detector stations, the visualisation program EmmaEve to scan events, the graphical monitoring program EmmaDiagnosticsGUI to control the functionality of detectors on-line, the efficiency monitoring program to control chamber efficiencies in three-layer stations and the design of the EMMA database to store reconstruction results. Especially the design and tests of ETANA form the backbone of the present work as its optimised performance is crucial for the analysis of EMMA data.
Furthermore, in the present work the influence of rock overburden above EMMA on the properties of high-energy muons is investigated by detailed simulations. The reconstruction of hits in drift chambers is studied with measured data including the estimation of the quality of reconstructed hits, the functionality of hit formation procedure and the influence of afterpulses on hit reconstruction. The validity of simulated data that are generated by the EMMA event generation program is evaluated by comparing simulated and measured data with each other. Finally, synergy benefits between the EMMA and ALICE experiments are discussed, which are both underground experiments but different in nature.
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The relationship between galactic cosmic rays and solar windIhongo, Grace Dominic January 2016 (has links)
Modeling the highly energetic particles known as galactic cosmic rays is a highly nontrivial task. This process may require numerical simulations of the complex processes occurring continuously in the heliosphere due to changes in solar wind reflecting the solar activity. However, if reasonable assumptions are employed, considering only the diffusion and convection processes, the above phenomenon can be reduced to a simplified scenario that can be modeled analytically. The variable solar wind may be responsible for solar modulation of galactic cosmic rays. The aforementioned, in addition to the postulated role of cosmic rays in climate change, has led to the following questions: what is the relationship between galactic cosmic rays and solar wind? What are the possible effects of solar wind on galactic cosmic ray flux? In an attempt to address these questions, we have modeled the transport of galactic cosmic rays in the heliosphere theoretically. Our model describes solar modulation and transport of galactic cosmic rays in the heliosphere mainly in terms of the size of the heliosphere, timedependent solar wind, and a uniform diffusion coefficient. Our results suggest that solar wind causes significant decrease in galactic cosmic ray flux at r ≈ 1AU. In further investigation, we examine a short-time variation of the calculated flux, and the result is reflected by exposing a negative correlation of −0.988 ± 0.001 between galactic cosmic ray flux variation and the solar wind variation at r ≈ 1AU. This outcome may suggest that the higher the solar wind, the lower the galactic cosmic ray flux and vice-versa. For completeness, we compared our results with available observational data that shows a good fit to the model. Thus, based on our model results, it may be possible to predict that galactic cosmic ray flux variation and solar wind variation at Earth are negatively correlated.
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