Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360686
Title: Gamma ray Cerenkov telescope image analysis
Author: Holder, Jamie
Awarding Body: Durham University
Current Institution: Durham University
Date of Award: 1997
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Abstract:
The subject of this thesis is ground based gamma ray astronomy using the imaging atmospheric Cerenkov technique. The first two chapters are introductory, and describe the field of gamma ray astronomy, the generation of extensive air showers in the atmosphere and the Cerenkov radiation they induce. Chapter three describes the atmospheric Cerenkov telescope, including the development of the imaging technique for background discrimination. The characteristics of the three University of Durham atmospheric Cerenkov telescopes and the processing and calibration of their data products are outlined. Chapter four is concerned with periodic sources of gamma ray emission and includes a review of candidate sources and time series analysis techniques. An analysis of the Mark 3 telescope SMC X-1 database is presented. An upper limit of 1.2 x 10(^-11) cm(^-2) s(^-1) above a cosmic ray threshold of 1 TeV is determined for the guard ring analysis of Mark 3 data. For an analysis of medium resolution Mark 3 imaging data, the upper limit is 2 x 10(^-10) cm(^-2) s(^-1) above a cosmic ray threshold of 500 GeV. Chapter five introduces a new method for the parameterisation of Cerenkov images of extensive air showers recorded by atmospheric Cerenkov telescopes. This method, involving the optimization of a bivariate Gaussian fit to the image, is shown to be significantly better than the standard moment based parameterisation using simulated images. In Chapter six, both of these methods are employed in an attempt to enhance the signal to noise ratio for observations of the pulsar PSR 1706-44 made with the Mark 6 telescope and some evidence for steady emission is seen. The implied fluxes are (2.6 ± 0.3 ± 0.1)x 10(^-11) cm(^-2) s(^-1) above 420 GeV for the bivariate Gaussian analysis and (1.7 ± 0.4 ± 0.2)x10(^-11) cm(^-2) s(^-1) above 500 GeV for the moment analysis.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.360686  DOI: Not available
Keywords: Astronomy Astronomy
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