Extreme galaxies: TeV gamma-ray emission from the Blazar 1ES 2344+514

Abstract

This thesis describes an investigation of Very High Energy (VHE) gamma-ray emission from the blazar galaxy 1ES 2344+514, based on data from five observational seasons (1999-2004) using the Whipple 10-metre telescope in southern Arizona. The 65 hours of data consists mostly of tracking observations without contiguous OFF-source control data. A matching procedure was used to select a surrogate OFF-run compatible with each ON-source observation, to allow for determination of the background signal. Analyses of the data was carried out using both the standard Supercuts criteria and the multivariate kernel method. The TeV flux of 1ES 2344+514, above 400 GeV, was determined to be (0.29 ± 0.14)xlO-7 m- 2s-1. To allow a comparison with the flux as determined by HEGRA from 1997 to 2002, the flux above 800 GeV was calculated to be (0.07 ± 0.04)xl0_7m_2s“1. This compares very well with the HEGRA value, althoughit is noted that the uncertainties are a factor of two larger. An estimate of the spectral index of 1ES 2344 is derived from the quiescent flux values, although the uncertainty on the value is extremely large due to the limited statistics.