11. Bounds on diffuse and point source fluxes of ultra-high energy neutrinos with the Pierre Auger ObservatoryFrancisco Pedreira, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, Auger Surface Detector, search for ultra-high energy (UHE) neutrinos, upper limits on diffuse and point source UHE neutrino fluxes Objavljeno v RUNG: 21.12.2020; Ogledov: 2512; Prenosov: 64 Celotno besedilo (447,71 KB) |
12. Analysis of Data from the Low-Energy Modes of the Surface Detector of the Pierre Auger ObservatoryMartin Schimassek, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavtranik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, Surface Detector, Low-Energy Modes Objavljeno v RUNG: 21.12.2020; Ogledov: 2321; Prenosov: 73 Celotno besedilo (919,66 KB) |
13. New Electronics for the Surface Detectors of the Pierre Auger ObservatoryD. Nitz, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: ultra-high energy cosmic rays, Pierre Auger Observatory, AugerPrime detector upgrade, Auger Surface Detectors, electronics Objavljeno v RUNG: 24.07.2020; Ogledov: 2634; Prenosov: 73 Celotno besedilo (7,57 MB) |
14. Reconstruction of Vertical Events Recorded by the Surface Detector of the Pierre Auger ObservatoryDaniela Mockler, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: ultra-high energy cosmic rays (UHECRs), Pierre Auger Observatory, Auger Surface Detector, vertical UHECR events, event reconstruction Objavljeno v RUNG: 24.07.2020; Ogledov: 2863; Prenosov: 80 Celotno besedilo (321,91 KB) |
15. Test benches for the upgrade of the Pierre AugerObservatory electronicsMartina Boháčová, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, surface detector station, electronics, test benches Objavljeno v RUNG: 16.06.2020; Ogledov: 2672; Prenosov: 77 Celotno besedilo (735,82 KB) |
16. CORSIKA Simulation of the Telescope Array Surface DetectorT. Abu-Zayyad, Jon Paul Lundquist, 2014, izvirni znanstveni članek Opis: The Telescope Array is the largest experiment studying ultra-high energy cosmic rays in the northern hemisphere. The detection area of the experiment consists of an array of 507 surface detectors, and a fluorescence detector divided into three sites at the periphery. The viewing directions of the 38 fluorescence telescopes point over the air space above the surface array. In this paper, we describe a technique that we have developed for simulating the response of the array of surface detectors of the Telescope Array experiment. The two primary components of this method are (a) the generation of a detailed CORSIKA Monte Carlo simulation with all known characteristics of the data, and (b) the validation of the simulation by a direct comparison with the Telescope Array surface detector data. This technique allows us to make a very accurate calculation of the acceptance of the array. We also describe a study of systematic uncertainties in this acceptance calculation. Ključne besede: cosmic ray, extensive air shower, simulation, surface detector Objavljeno v RUNG: 19.05.2020; Ogledov: 2662; Prenosov: 0 Gradivo ima več datotek! Več... |
17. Search for EeV protons of galactic originR.U. Abbasi, Jon Paul Lundquist, 2016, izvirni znanstveni članek Opis: Cosmic rays in the energy range 10^18.0–10^18.5 eV are thought to have a light, probably protonic, composition. To study their origin one can search for anisotropy in their arrival directions. Extragalactic cosmic rays should be isotropic, but galactic cosmic rays of this type should be seen mostly along the galactic plane, and there should be a shortage of events coming from directions near the galactic anticenter. This is due to the fact that, under the influence of the galactic magnetic field, the transition from ballistic to diffusive behavior is well advanced, and this qualitative picture persists over the whole energy range. Guided by models of the galactic magnetic field that indicate that the enhancement along the galactic plane should have a standard deviation of about 20° in galactic latitude, and the deficit in the galactic anticenter direction should have a standard deviation of about 50° in galactic longitude, we use the data of the Telescope Array surface detector in 10^18.0 to 10^18.5 eV energy range to search for these effects. The data are isotropic. Neither an enhancement along the galactic plane nor a deficit in the galactic anticenter direction is found. Using these data we place an upper limit on the fraction of EeV cosmic rays of galactic origin at 1.3% at 95% confidence level. Ključne besede: Cosmic ray, Galactic protons, Telescope array, Surface detector Objavljeno v RUNG: 30.04.2020; Ogledov: 2820; Prenosov: 0 Gradivo ima več datotek! Več... |
18. Gamma Ray Showers Observed at Ground Level in Coincidence With Downward Lightning LeadersR.U. Abbasi, Jon Paul Lundquist, 2018, izvirni znanstveni članek Opis: Bursts of gamma ray showers have been observed in coincidence with downward propagating negative leaders in lightning flashes by the Telescope Array Surface Detector (TASD). The TASD is a 700‐km^2 cosmic ray observatory located in southwestern Utah, USA. In data collected between 2014 and 2016, correlated observations showing the structure and temporal development of three shower‐producing flashes were obtained with a 3‐D lightning mapping array, and electric field change measurements were obtained for an additional seven flashes, in both cases colocated with the TASD. National Lightning Detection Network information was also used throughout. The showers arrived in a sequence of 2–5 short‐duration (≤10 μs) bursts over time intervals of several hundred microseconds and originated at an altitude of ≃3–5 km above ground level during the first 1–2 ms of downward negative leader breakdown at the beginning of cloud‐to‐ground lightning flashes. The shower footprints, associated waveforms and the effect of atmospheric propagation indicate that the showers consist primarily of downward‐beamed gamma radiation. This has been supported by GEANT simulation studies, which indicate primary source fluxes of ≃10^12–10^14 photons for 16° half‐angle beams. We conclude that the showers are terrestrial gamma ray flashes, similar to those observed by satellites, but that the ground‐based observations are more representative of the temporal source activity and are also more sensitive than satellite observations, which detect only the most powerful terrestrial gamma ray flashes. Ključne besede: gamma rays, lightning, gamma ray bursts, surface detector Objavljeno v RUNG: 30.04.2020; Ogledov: 3239; Prenosov: 0 Gradivo ima več datotek! Več... |
19. TA Anisotropy SummaryK. Kawata, Jon Paul Lundquist, 2019, objavljeni znanstveni prispevek na konferenci Opis: The Telescope Array (TA) is the largest ultra-high-energy cosmic-ray (UHECR) detector in the northern hemisphere. It consists of an array of 507 surface detectors (SD) covering a total 700 km^2 and three fluorescence detector stations overlooking the SD array. In this proceedings, we summarize recent results on the search for directional anisotropy of UHECRs using the latest dataset collected by the TA SD array. We obtained hints of the anisotropy of the UHECRs in the northern sky from the various analyses. Ključne besede: cosmic radiation, UHE detector, fluorescence detector, surface, Telescope Array Experiment, anisotropy, experimental results Objavljeno v RUNG: 28.04.2020; Ogledov: 3158; Prenosov: 78 Celotno besedilo (1,88 MB) |
20. Search for Anisotropy in the Ultra High Energy Cosmic Ray Spectrum using the Telescope Array Surface DetectorR.U. Abbasi, Jon Paul Lundquist, 2017, drugi sestavni deli Opis: The Telescope Array (TA) experiment is located in the western desert of Utah, USA, and observes ultra high energy cosmic rays (UHECRs) in the Northern hemisphere. At the highest energies, E>10~EeV, the shape of cosmic ray energy spectrum may carry an imprint of the source density distribution along the line of sight different in different directions of the sky. In this study, we search for such directional variations in the shape of the energy spectrum using events observed with the Telescope Array's surface detector. We divide the TA field of view into two nearly equal-exposure regions: the "on-source" region which we define as ±30∘ of the supergalactic plane containing mostly nearby structures, and the complementary "off-source" region where the sources are further away on average. We compare the UHECR spectra in these regions by fitting them to the broken power law and comparing the resulting parameters. We find that the off-source spectrum has an earlier break at highest energies. The chance probability to obtain such or larger difference in statistically equivalent distributions is estimated as 6.2±1.1×10−4 (3.2σ) by a Monte-Carlo simulation. The observed difference in spectra is in a reasonable quantitative agreement with a simplified model that assumes that the UHECR sources trace the galaxy distribution from the 2MRS catalogue, primary particles are protons and the magnetic deflections can be neglected. Ključne besede: cosmic radiation: UHE, detector: surface, cosmic radiation: spectrum, cosmic radiation: energy spectrum, deflection: magnetic, numerical calculations: Monte Carlo, anisotropy Objavljeno v RUNG: 27.04.2020; Ogledov: 3000; Prenosov: 98 Celotno besedilo (169,05 KB) |