221. Multi-Messenger Physics With the Pierre Auger ObservatoryKarl-Heinz Kampert, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, original scientific article Keywords: Pierre Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics and astrophysics Published in RUNG: 06.05.2019; Views: 3350; Downloads: 107 Full text (2,46 MB) |
222. Monte Carlo studies for the optimisation of the Cherenkov Telescope Array layoutA. Acharyya, Samo Stanič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2019, original scientific article Keywords: very-high energy gamma-ray astronomy, Cherenkov Telescope Array, array layout optimisation, Monte Carlo studies Published in RUNG: 18.04.2019; Views: 3099; Downloads: 0 This document has many files! More... |
223. Mass composition of ultra-high energy cosmic rays at the Pierre Auger ObservatoryGašper Kukec Mezek, 2019, doctoral dissertation Abstract: Cosmic rays with energies above 10^18 eV, usually referred to as ultra-high energy cosmic rays (UHECR), have been a mystery from the moment they have been discovered. Although we have now more information on their extragalactic origin, their direct sources still remain hidden due to deviations caused by galactic magnetic fields. Another mystery, apart from their production sites, is their nature. Their mass composition, still uncertain at these energies, would give us a better understanding on their production, acceleration, propagation and capacity to produce extensive air showers in the Earth's atmosphere. Mass composition studies of UHECR try to determine their nature from the difference in development of their extensive air showers.
In this work, observational parameters from the hybrid detection system of the Pierre Auger Observatory are used in a multivariate analysis to obtain the mass composition of UHECR. The multivariate analysis (MVA) approach combines a number of mass composition sensitive variables and tries to improve the separation between different UHECR particle masses. Simulated distributions of different primary particles are fitted to measured observable distributions in order to determine individual elemental fractions of the composition. When including observables from the surface detector, we find a discrepancy in the estimated mass composition between a mixed simulation sample and the Pierre Auger data. Our analysis results from the Pierre Auger data are to a great degree independent on hadronic interaction models. Although they differ at higher primary masses, the different models are more consistent, when combining fractions of oxygen and iron. Compared to previously published results, the systematic uncertainty from hadronic interaction models is roughly four times smaller. Our analysis reports a predominantly heavy composition of UHECR, with more than a 50% fraction of oxygen and iron at low energies. The composition is then becoming heavier with increasing energy, with a fraction of oxygen and iron above 80% at the highest energies. Keywords: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, machine learning, multivariate analysis Published in RUNG: 03.04.2019; Views: 5001; Downloads: 187 Full text (17,53 MB) |
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225. Probing Lorentz symmetry with the Pierre Auger ObservatoryD. Boncioli, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: Pierre Auger Observatory, Lorentz invariance violation, ultra-high energy cosmic rays Published in RUNG: 16.02.2018; Views: 3239; Downloads: 150 Full text (309,46 KB) |
226. Supernova remnants in the very-high-energy sky: prospects for the Cherenkov Telescope ArrayP. Cristofari, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: supernova remnants, CTA, very-high-energy Published in RUNG: 16.02.2018; Views: 3365; Downloads: 178 Full text (228,59 KB) |
227. Diffuse and targeted searches for ultra-high-energy photons using the hybrid detector of the Pierre Auger ObservatoryMarcus Niechciol, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: ultra-high-energy photons, Pierre Auger Observatory, hybrid detector Published in RUNG: 16.02.2018; Views: 3247; Downloads: 149 Full text (383,49 KB) |
228. Observing the sky at extremely high energies with CTA: Status of the GCT projectHelene Sol, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: very high energy, CTA, GCT Published in RUNG: 16.02.2018; Views: 2819; Downloads: 163 Full text (916,79 KB) |
229. A Compact High Energy Camera (CHEC) for the Gamma-ray Cherenkov Telescope of the Cherenkov Telescope ArrayIain R. White, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: Compact High Energy Camera, CTA, Gamma-ray Cherenkov Telescope Published in RUNG: 16.02.2018; Views: 3061; Downloads: 107 Full text (6,76 MB) |
230. Extragalactic source population studies at very high energies in the Cherenkov Telescope Array eraT. Hassan, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: very high energy, CTA, extragalactic source Published in RUNG: 16.02.2018; Views: 3389; Downloads: 138 Full text (651,65 KB) |