A search for very high-energy gamma-ray emission from pulsars with VERITAS
Richards, Gregory T.
MetadataShow full item record
Pulsars are powerful cosmic particle accelerators known to emit radiation across the entire electromagnetic spectrum. Their gamma-ray emission has been intensely studied at energies up to ~10 GeV, above which the predicted and observed fluxes rapidly decline due to characteristics of the radiation mechanism. The recent and unexpected detection of very high-energy (VHE, E > 100 GeV) gamma-ray emission from the Crab pulsar has posed a novel and exciting challenge for experimentalists and theoreticians alike. In the time since its detection above 100 GeV with the Imaging Atmospheric Cherenkov Telescope (IACT) array VERITAS, no other pulsar has been firmly detected in the same energy band despite ongoing observational efforts by multiple IACT collaborations. The origin of the pulsed VHE emission from the Crab is currently the subject of an ongoing debate in the literature with no complete solution, since model predictions do not adequately explain the observed features of the VHE radiation. To better understand the VHE gamma-ray production mechanism of pulsars, I have conducted a search for periodic emission above 100 GeV from a total of 16 pulsars with VERITAS comprising a set of data with an exposure in excess of 580 hours. The set of pulsars includes many of the youngest and brightest gamma-ray pulsars visible in the northern hemisphere. The data analysis presented in this thesis in every case resulted in non-detections of pulsed gamma rays above 100 GeV. Upper limits on a potential VHE flux for each pulsar are presented, and these limits place strong constraints on a possible flux component manifesting at VHEs as is seen for the Crab pulsar.