TY  - THES
AB  - The subject of the present thesis is the search for photons in the EeV range in cosmic-ray data collected at the Pierre Auger Observatory. Photons, in general, are the main messenger particles for the exploration of the Universe. An observation of photons in the EeV range, the existence of which is predicted by many current theories about the origin of Ultra-High-Energy Cosmic Rays (UHECRs), would not only open a new observational window to the Universe, but would also further our understanding of UHECRs in general. The Pierre Auger Observatory offers an unprecedented exposure to UHE particles and thus provides a unique opportunity to search for UHE photons. In order to distinguish extensive air showers induced by photons from the hadronic background, a combination of the observable Xmax, which is directly measured by the Fluorescence Detector (FD), and the novel observable Fgamma, which is determined from the signals recorded by the Surface Detector (SD), is employed. Both observables are combined in a multivariate Fisher discriminant analysis. Applying this analysis to data collected at the Pierre Auger Observatory between 2004 and 2012, one event with photon-like characteristics is found. From this result, upper limits on the fraction of photons in the total flux of cosmic rays in the EeV range are determined, which are on par with the most stringent limits set by previous analyses.
AU  - Niechciol, Marcus
DA  - 2015
KW  - UHECR
KW  - Astroteilchenphysik
KW  - Astroparticle Physics
KW  - Multivariate Analysis
LA  - eng
PY  - 2015
TI  - A new window to the universe? : searching for ultra-high-energy photons at the Pierre Auger Observatory
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:467-9346
Y2  - 2024-11-22T03:40:48
ER  -