51. 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: 2837; Prenosov: 98
 Celotno besedilo (169,05 KB) |
52. Evidence for Declination Dependence of Ultrahigh Energy Cosmic Ray Spectrum in the Northern HemisphereR.U. Abbasi, Jon Paul Lundquist, 2018, drugi sestavni deli Opis: The energy of the ultrahigh energy spectral cutoff was measured, integrating over the northern hemisphere sky, by the Telescope Array (TA) collaboration, to be 10^19.78±0.06 eV, in agreement with the High Resolution Fly's Eye (HiRes) experiment, whereas the Pierre Auger experiment, integrating over the southern hemisphere sky, measured the cutoff to be at 10^19.62±0.02 eV. An 11% energy scale difference between the TA and Auger does not account for this difference. However, in comparing the spectra of the Telescope Array and Pierre Auger experiments in the band of declination common to both experiments ( −15.7∘<δ<24.8∘ ) we have found agreement in the energy of the spectral cutoff. While the Auger result is essentially unchanged, the TA cutoff energy has changed to 10^19.59±0.06 eV. In this paper we argue that this is an astrophysical effect.
Ključne besede: Astrophysics, High Energy Astrophysical Phenomena, UHECR, Cosmic Rays, Anisotropy, Energy Spectrum
Objavljeno v RUNG: 27.04.2020; Ogledov: 2952; Prenosov: 92
Celotno besedilo (687,87 KB) |
53. Report of the Telescope Array - Pierre Auger Observatory Working Group on Energy SpectrumDmitri Ivanov, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Darko Veberič, Serguei Vorobiov, Marta Trini, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, objavljeni znanstveni prispevek na konferenci Ključne besede: Telescope Array, Pierre Auger Observatory, Energy Spectrum
Objavljeno v RUNG: 19.02.2018; Ogledov: 3392; Prenosov: 172
Celotno besedilo (398,98 KB) |
54. The cosmic ray energy spectrum measured using the Pierre Auger ObservatoryFrancesco Fenu, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, objavljeni znanstveni prispevek na konferenci Ključne besede: cosmic ray, energy spectrum, Pierre Auger Observatory
Objavljeno v RUNG: 16.02.2018; Ogledov: 2953; Prenosov: 145
Celotno besedilo (566,33 KB) |
55. Results from the Pierre Auger ObservatoryIvan De Mitri, Andrej Filipčič, Samo Stanič, Darko Veberič, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, Ultra High Energy Cosmic Rays (UHECR), UHECR energy spectrum, UHECR mass composition
Objavljeno v RUNG: 27.06.2017; Ogledov: 4138; Prenosov: 0
Gradivo ima več datotek! Več... |
56. Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger ObservatoryA. Aab, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, izvirni znanstveni članek Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays (UHECR), UHECR anisotropies, angular power spectrum, needlet wavelet analysis
Objavljeno v RUNG: 23.06.2017; Ogledov: 4131; Prenosov: 0
Gradivo ima več datotek! Več... |
57. Astroparticles at the High Energy Frontier: Results from the Pierre Auger ObservatoryGonzalo Parente, Andrej Filipčič, Ahmed Saleh, Samo Stanič, Darko Veberič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2014, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays (UHECR), UHECR energy spectrum, mass composition, anisotropies
Objavljeno v RUNG: 20.06.2017; Ogledov: 4896; Prenosov: 0
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58. Auger HighlightsAntonella Castellina, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2014, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, ultra high energy cosmic rays (UHECR), UHECR hybrid detection technique, UHECR energy spectrum, UHECR mass composition, UHECR arrival directions
Objavljeno v RUNG: 20.06.2017; Ogledov: 5131; Prenosov: 395
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59. Evidence for a mixed mass composition at the ‘ankle’ in the cosmic-ray spectrumA. Aab, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2016, izvirni znanstveni članek Ključne besede: ultra-high energy cosmic rays (UHECR), UHECR mass composition, UHECR energy spectrum, Pierre Auger Observatory, composition studies at the ‘ankle’ region in the UHECR spectrum
Objavljeno v RUNG: 25.11.2016; Ogledov: 4727; Prenosov: 180
Celotno besedilo (1,73 MB) |
60. Measurement of the energy spectrum of cosmic rays with the Pierre Auger ObservatoryValerio Verzi, Andrej Filipčič, Ahmed Saleh, Samo Stanič, Lili Yang, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2016, objavljeni znanstveni prispevek na konferenci Ključne besede: ultra-high energy cosmic rays (UHECR), Pierre Auger Observatory, UHECR energy spectrum
Objavljeno v RUNG: 17.11.2016; Ogledov: 4624; Prenosov: 0
Gradivo ima več datotek! Več... |
