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31.
Results from the Pierre Auger Observatory
Marko Zavrtanik, Danilo Zavrtanik, Darko Veberič, Samo Stanič, Andrej Filipčič, Ivan De Mitri, 2015, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...Pierre Auger Observatory, Ultra High Energy Cosmic Rays (UHECR), UHECR energy spectrum, UHECR mass composition...
Keywords: Pierre Auger Observatory, Ultra High Energy Cosmic Rays (UHECR), UHECR energy spectrum, UHECR mass composition
Published: 27.06.2017; Views: 1551; Downloads: 0
.pdf Fulltext (475,69 KB)

32.
Astroparticle studies at the Pierre Auger Observatory
Lili Yang, invited lecture at foreign university

Abstract: The Pierre Auger Observatory (PAO), the world’s largest cosmic ray detector combines a large surface detector (SD) with an air fluorescence detector (FD). It is designed to observe extensive air showers (EAS) of billions of secondary particles induced by the UHECRs in the earths’ atmosphere. The “hybrid” design (i.e., detected simultaneously by SD and FD) provides wealth of information about shower development and excellent event reconstruction. Together with observations of UHECRs, the Surface Detector (SD) of the PAO is sensitive to UHE neutrinos through the observation of deeply initiated inclined down-going showers produced by neutrino interactions in the atmosphere, which method has been well established. On the other hand, high-energy photons can also be discriminated from background of charged cosmic rays based on their characters of the shower front. In this talk, I will give a review on recent results from PAO and introduce the ultra-high energy multi-messenger studies from PAO.
Found in: ključnih besedah
Summary of found: ...Pierre Auger Observatory (PAO), the world’s largest cosmic ray detector combines a large surface detector... ...be discriminated from background of charged cosmic rays based on their characters of the shower...
Keywords: Pierre Auger Observatory, cosmic rays, ultra-high energy
Published: 17.01.2018; Views: 1087; Downloads: 0
.pdf Fulltext (8,86 MB)
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33.
Probing Lorentz symmetry with the Pierre Auger Observatory
Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Darko Veberič, Marta Trini, Samo Stanič, Ahmed Saleh, Gašper Kukec Mezek, Andrej Filipčič, D. Boncioli, 2017, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...Observatory, Lorentz invariance violation, ultra-high energy cosmic rays...
Keywords: Pierre Auger Observatory, Lorentz invariance violation, ultra-high energy cosmic rays
Published: 16.02.2018; Views: 870; Downloads: 80
.pdf Fulltext (309,46 KB)

34.
Multi-Messenger Physics With the Pierre Auger Observatory
Karl-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

Found in: ključnih besedah
Summary of found: ...Pierre Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics and...
Keywords: Pierre Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics and astrophysics
Published: 06.05.2019; Views: 687; Downloads: 43
.pdf Fulltext (2,46 MB)

35.
Mass composition of ultra-high energy cosmic rays at the Pierre Auger Observatory
Gašper 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.
Found in: ključnih besedah
Keywords: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, machine learning, multivariate analysis
Published: 03.04.2019; Views: 1103; Downloads: 62
.pdf Fulltext (17,53 MB)

36.
Mass composition of cosmic rays with energies from 10^17.2 eV to 10^20 eV using surface and fluorescence detectors of the Pierre Auger Observatory
Gašper Kukec Mezek, 2018, published scientific conference contribution

Abstract: Ultra-high-energy cosmic rays (UHECRs) are highly energetic particles with EeV energies, exceeding the capabilities of man-made colliders. They hold information on extreme astrophysical processes that create them and the medium they traverse on their way towards Earth. However, their mass composition at such energies is still unclear, because data interpretation depends on our choice of high energy hadronic interaction models. With its hybrid detection method, the Pierre Auger Observatory has the possibility to detect extensive air showers with an array of surface water-Cherenkov stations (SD) and fluorescence telescopes (FD). We present recent mass composition results from the Pierre Auger Collaboration using observational parameters from SD and FD measurements. Using the full dataset of the Pierre Auger Observatory, implications on composition can be made for energies above 10^17.2 eV.
Found in: ključnih besedah
Summary of found: ... Ultra-high-energy cosmic rays (UHECRs) are highly energetic particles...
Keywords: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, fluorescence telescopes, water-Cherenkov stations
Published: 24.05.2019; Views: 800; Downloads: 43
.pdf Fulltext (573,00 KB)

37.
Study of Ultra-High Energy Cosmic Ray composition using Telescope Array’s Middle Drum detector and surface array in hybrid mode
J. P. Lundquist, R.U. Abbasi, 2015, original scientific article

Abstract: Previous measurements of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly’s Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory, but utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in some, but not all, respects in methodology to PAO, and good agreement is evident between data and a light, largely protonic, composition when comparing the measurements to predictions obtained with the QGSJetII-03 and QGSJet-01c models. These models are also in agreement with previous HiRes stereo measurements, confirming the equivalence of the stereo and hybrid methods. The data is incompatible with a pure iron composition, for all models examined, over the available range of energies. The elongation rate and mean values of are in good agreement with Pierre Auger Observatory data. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.
Found in: ključnih besedah
Summary of found: ...of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly’s...
Keywords: Ultra-High Energy Cosmic Rays, Cosmic ray composition, Atmospheric fluorescence, Extensive air shower array, Hybrid, Telescope Array
Published: 24.04.2020; Views: 426; Downloads: 0
.pdf Fulltext (3,45 MB)

38.
The energy spectrum of cosmic rays above 1017.2 eV measured by the fluorescence detectors of the Telescope Array experiment in seven years
J. P. Lundquist, R.U. Abbasi, 2016, original scientific article

Abstract: The Telescope Array (TA) experiment is the largest detector to observe ultra-high-energy cosmic rays in the northern hemisphere. The fluorescence detectors at two stations of TA are newly constructed and have now completed seven years of steady operation. One advantage of monocular analysis of the fluorescence detectors is a lower energy threshold for cosmic rays than that of other techniques like stereoscopic observations or coincidences with the surface detector array, allowing the measurement of an energy spectrum covering three orders of magnitude in energy. Analyzing data collected during those seven years, we report the energy spectrum of cosmic rays covering a broad range of energies above 10^17.2eV measured by the fluorescence detectors and a comparison with previously published results.
Found in: ključnih besedah
Keywords: Cosmic rays, Ultra-high energy, Fluorescence detector, Energy spectrum, Ankle, GZK cutoff
Published: 27.04.2020; Views: 355; Downloads: 0
.pdf Fulltext (1,23 MB)

39.
Measurement of the proton-air cross section with Telescope Array’s Middle Drum detector and surface array in hybrid mode
J. P. Lundquist, R.U. Abbasi, 2015, original scientific article

Found in: ključnih besedah
Summary of found: ... Cosmic Rays, proton cross-section, ultra-high energy, particle physics...
Keywords: Cosmic Rays, proton cross-section, ultra-high energy, particle physics
Published: 27.04.2020; Views: 359; Downloads: 0
.pdf Fulltext (409,81 KB)

40.
The hybrid energy spectrum of Telescope Array’s Middle Drum Detector and surface array
J. P. Lundquist, R.U. Abbasi, 2015, original scientific article

Abstract: The Telescope Array experiment studies ultra high energy cosmic rays using a hybrid detector. Fluorescence telescopes measure the longitudinal development of the extensive air shower generated when a primary cosmic ray particle interacts with the atmosphere. Meanwhile, scintillator detectors measure the lateral distribution of secondary shower particles that hit the ground. The Middle Drum (MD) fluorescence telescope station consists of 14 telescopes from the High Resolution Fly’s Eye (HiRes) experiment, providing a direct link back to the HiRes measurements. Using the scintillator detector data in conjunction with the telescope data improves the geometrical reconstruction of the showers significantly, and hence, provides a more accurate reconstruction of the energy of the primary particle. The Middle Drum hybrid spectrum is presented and compared to that measured by the Middle Drum station in monocular mode. Further, the hybrid data establishes a link between the Middle Drum data and the surface array. A comparison between the Middle Drum hybrid energy spectrum and scintillator Surface Detector (SD) spectrum is also shown.
Found in: ključnih besedah
Summary of found: ...Telescope Array experiment studies ultra high energy cosmic rays using a hybrid detector. Fluorescence telescopes...
Keywords: Cosmic rays, Energy spectrum, Telescope Array, Hybrid, Ultra high energy
Published: 27.04.2020; Views: 339; Downloads: 0
.pdf Fulltext (3,12 MB)

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