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101.
Search for anisotropy of ultrahigh energy cosmic rays with the Telescope Array experiment
J. P. Lundquist, T. Abu-Zayyad, 2012, original scientific article

Abstract: We study the anisotropy of Ultra-High Energy Cosmic Ray (UHECR) events collected by the Telescope Array (TA) detector in the first 40 months of operation. Following earlier studies, we examine event sets with energy thresholds of 10 EeV, 40 EeV, and 57 EeV. We find that the distributions of the events in right ascension and declination are compatible with an isotropic distribution in all three sets. We then compare with previously reported clustering of the UHECR events at small angular scales. No significant clustering is found in the TA data. We then check the events with E > 57 EeV for correlations with nearby active galactic nuclei. No significant correlation is found. Finally, we examine all three sets for correlations with the large-scale structure (LSS) of the universe. We find that the two higher-energy sets are compatible with both an isotropic distribution and the hypothesis that UHECR sources follow the matter distribution of the universe (the LSS hypothesis), while the event set with E > 10 EeV is compatible with isotropy and is not compatible with the LSS hypothesis at 95% CL unless large deflection angles are also assumed. We show that accounting for UHECR deflections in a realistic model of the Galactic magnetic field can make this set compatible with the LSS hypothesis.
Found in: ključnih besedah
Keywords: acceleration of particles, astroparticle physics, cosmic rays, magnetic fields, methods: statistical, relativistic processes
Published: 19.05.2020; Views: 1197; Downloads: 0
.pdf Fulltext (1,04 MB)

102.
New air fluorescence detectors employed in the Telescope Array experiment
J. P. Lundquist, H. Tokuno, 2012, original scientific article

Abstract: Since 2007, the Telescope Array (TA) experiment, based in Utah, USA, has been observing ultra high energy cosmic rays to understand their origins. The experiment includes a surface detector (SD) array and three fluorescence detector (FD) stations. The FD stations, installed surrounding the SD array, measure the air fluorescence light emitted from extensive air showers (EASs) for precise determination of their energies and species. The detectors employed at one of the three FD stations were relocated from the High Resolution Fly's Eye (HiRes) experiment. At the other two stations, newly designed detectors were constructed for the TA experiment. An FD consists of a primary mirror and a camera equipped with photomultiplier tube pixels. To obtain the EAS parameters with high accuracy, understanding the FD optical characteristics is important. In this paper, we report the characteristics and installation of the new FDs and the performances of the FD components. The results of the monitored mirror reflectance during the observation time are also described in this report.
Found in: ključnih besedah
Summary of found: ...USA, has been observing ultra high energy cosmic rays to understand their origins. The experiment...
Keywords: Ultra high energy cosmic rays, Extensive air showers, Air fluorescence light detectors
Published: 19.05.2020; Views: 1056; Downloads: 0
.pdf Fulltext (1,44 MB)

103.
Evidence for a Supergalactic Structure of Magnetic Deflection Multiplets of Ultra-High Energy Cosmic Rays
J. P. Lundquist, R. Abbasi, 2020, original scientific article

Abstract: Evidence for a large-scale supergalactic cosmic ray multiplet (arrival directions correlated with energy) structure is reported for ultra-high energy cosmic ray (UHECR) energies above 10^19 eV using seven years of data from the Telescope Array (TA) surface detector and updated to 10 years. Previous energy-position correlation studies have made assumptions regarding magnetic field shapes and strength, and UHECR composition. Here the assumption tested is that, since the supergalactic plane is a fit to the average matter density of the local Large Scale Structure (LSS), UHECR sources and intervening extragalactic magnetic fields are correlated with this plane. This supergalactic deflection hypothesis is tested by the entire field-of-view (FOV) behavior of the strength of intermediate-scale energy-angle correlations. These multiplets are measured in spherical cap section bins (wedges) of the FOV to account for coherent and random magnetic fields. The structure found is consistent with supergalactic deflection, the previously published energy spectrum anisotropy results of TA (the hotspot and coldspot), and toy-model simulations of a supergalactic magnetic sheet. The seven year data post-trial significance of this supergalactic structure of multiplets appearing by chance, on an isotropic sky, is found by Monte Carlo simulation to be 4.19σ. The ten years of data post-trial significance is 4.09σ. Furthermore, the starburst galaxy M82 is shown to be a possible source of the TA Hotspot, and an estimate of the supergalactic magnetic field using UHECR measurements is presented.
Found in: ključnih besedah
Keywords: astroparticle physics, cosmic rays, UHECR, supergalactic plane, multiplets, magnetic deflection, large-scale structure of universe
Published: 19.05.2020; Views: 1098; Downloads: 0
.pdf Fulltext (4,40 MB)

104.
Highlights from the Pierre Auger Observatory
Lukas Zehrer, Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Marta Trini, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, Antonella Castellina, 2019, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...ultra-high energy cosmic rays, extensive air showers, Pierre Auger Observatory...
Keywords: ultra-high energy cosmic rays, extensive air showers, Pierre Auger Observatory
Published: 16.06.2020; Views: 1128; Downloads: 45
.pdf Fulltext (4,92 MB)

105.
Anisotropies of the highest energy cosmic-ray events recorded by the Pierre Auger Observatory in 15 years of operation
Lukas Zehrer, Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Marta Trini, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, Lorenzo Caccianiga, 2019, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...ultra-high energy cosmic rays (UHECR), UHECR anisotropies, Pierre Auger Observatory...
Keywords: ultra-high energy cosmic rays (UHECR), UHECR anisotropies, Pierre Auger Observatory
Published: 16.06.2020; Views: 1051; Downloads: 51
.pdf Fulltext (1,65 MB)

106.
Long Term Performance of the Pierre Auger Observatory
Lukas Zehrer, Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Marta Trini, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, Koun Choi, 2019, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...ultra-high energy cosmic rays, Pierre Auger Observatory, long term performance...
Keywords: ultra-high energy cosmic rays, Pierre Auger Observatory, long term performance
Published: 16.06.2020; Views: 1066; Downloads: 45
.pdf Fulltext (1,14 MB)

107.
Measurement of the cosmic ray flux near the second knee with the Pierre Auger Observatory
Lukas Zehrer, Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Marta Trini, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, Alan Coleman, 2019, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...ultra-high energy cosmic rays (UHECR), UHECR energy spectrum, second knee, Pierre...
Keywords: ultra-high energy cosmic rays (UHECR), UHECR energy spectrum, second knee, Pierre Auger Observatory
Published: 16.06.2020; Views: 1065; Downloads: 40
.pdf Fulltext (557,92 KB)

108.
The Energy Scale of the Pierre Auger Observatory
Lukas Zehrer, Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Marta Trini, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, Bruce R. Dawson, 2019, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...ultra-high energy cosmic rays, Pierre Auger Observatory, energy scale...
Keywords: ultra-high energy cosmic rays, Pierre Auger Observatory, energy scale
Published: 16.06.2020; Views: 1061; Downloads: 38
.pdf Fulltext (277,08 KB)

109.
Social Impact of Outreach at the Pierre Auger Observatory
Lukas Zehrer, Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Marta Trini, Samo Stanič, Gašper Kukec Mezek, Andrej Filipčič, Beatriz García, 2019, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...ultra-high energy cosmic rays, Pierre Auger Observatory, outreach, social impact...
Keywords: ultra-high energy cosmic rays, Pierre Auger Observatory, outreach, social impact
Published: 16.06.2020; Views: 1014; Downloads: 38
.pdf Fulltext (5,83 MB)

110.
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