scholarly journals TA Anisotropy Summary

2019 ◽  
Vol 210 ◽  
pp. 01004 ◽  
Author(s):  
K. Kawata ◽  
A. di Matteo ◽  
T. Fujii ◽  
D. Ivanov ◽  
C.C.H. Jui ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Fluorescence Detector ◽  
Telescope Array ◽  
Directional Anisotropy

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 km2 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.

scholarly journals Measurements of UHECR Mass Composition by Telescope Array

2019 ◽  
Vol 210 ◽  
pp. 01008
Author(s):  
William Hanlon
Keyword(s):  
Monte Carlo ◽  
Cosmic Ray ◽  
High Energy ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Fluorescence Detector ◽  
Telescope Array ◽  
Second Moments ◽  
Systematic Uncertainties ◽  
Surface Detector

Telescope Array (TA) has recently published results of nearly nine years of Xmax observations providing its highest statistics measurement of ultra high energy cosmic ray (UHECR) mass composition to date for energies exceeding 1018.2 eV. This analysis measured agreement of observed data with results expected for four different single elements. Instead of relying only on the first and second moments of Xmax distributions, we employ a morphological test of agreement between data and Monte Carlo to allow for systematic uncertainties in data and in current UHECR hadronic models. Results of this latest analysis and implications of UHECR composition observed by TA are presented. TA can utilize different analysis methods to understand composition as both a crosscheck on results and as a tool to understand systematics affecting Xmax measurements. The different analysis efforts utilizing fluorescence detector stereo, surface detector and fluorescence detector hybrid, and surface detector-only, currently underway at TA performed to understand composition are also discussed.

scholarly journals Anisotropy search in the Ultra High Energy Cosmic Ray Spectrum in the Northern Hemisphere using the Telescope Array surface d

2016 ◽  
Author(s):  
Toshiyuki Nonaka ◽  
Robert Cady ◽  
Masaki Fukushima ◽  
Dmitri Ivanov ◽  
Kazumasa Kawata ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Telescope Array

scholarly journals Search for point sources of ultra-high-energy photons with the Telescope Array surface detector

2020 ◽  
Vol 492 (3) ◽  
pp. 3984-3993 ◽  
Author(s):  
R U Abbasi ◽  
M Abe ◽  
T Abu-Zayyad ◽  
M Allen ◽  
R Azuma ◽  
...  
Keyword(s):  
Point Source ◽  
Cosmic Ray ◽  
High Energy ◽  
Point Sources ◽  
Ultra High Energy ◽  
Telescope Array ◽  
Air Shower ◽  
Upper Limits ◽  
Surface Detector ◽  
Blind Search

ABSTRACT The surface detector (SD) of the Telescope Array (TA) experiment allows us to detect indirectly photons with energies of the order of 1018 eV and higher, and to separate photons from the cosmic ray background. In this paper, we present the results of a blind search for point sources of ultra-high-energy (UHE) photons in the Northern sky using the TA SD data. The photon-induced extensive air showers are separated from the hadron-induced extensive air shower background by means of a multivariate classifier based upon 16 parameters that characterize the air shower events. No significant evidence for the photon point sources is found. The upper limits are set on the flux of photons from each particular direction in the sky within the TA field of view, according to the experiment’s angular resolution for photons. The average 95 per cent confidence level upper-limits for the point-source flux of photons with energies greater than 1018, 1018.5, 1019, 1019.5 and 1020 eV are 0.094, 0.029, 0.010, 0.0073 and 0.0058 km−2yr−1, respectively. For energies higher than 1018.5 eV, the photon point-source limits are set for the first time. Numerical results for each given direction in each energy range are provided as a supplement to this paper.

scholarly journals Analysis of atmospheric attenuation using the Telescope Array central laser data

2019 ◽  
Vol 197 ◽  
pp. 01003 ◽  
Author(s):  
Tareq AbuZayyad
Keyword(s):  
Uv Light ◽  
Light Attenuation ◽  
Cosmic Ray ◽  
High Energy ◽  
Western Desert ◽  
Atmospheric Attenuation ◽  
Fluorescence Detector ◽  
Telescope Array ◽  
Laser Facility ◽  
Scintillator Detectors

Located in the western desert of the state of Utah, the Telescope Array (TA) experiment measures the properties of ultra high energy cosmic ray (UHECR) induced extensive air showers. TA employs a hybrid detector comprised of a large surface array of scintillator detectors overlooked by three fluorescence telescopes stations. The TA Low Energy extension (TALE) detector has operated as a monocular Cherenkov/fluorescence detector for nearly five years, and has recently been complemented by a closely spaced surface array to operate in hybrid mode. The TAx4 upgrade is underway and aims to, as the name suggests, quadruple the size of the surface array to improve statistics at the highest energies (post-GZK events). The analysis of the TA fluorescence detectors (FD) data requires knowledge of the degree of the atmospheric attenuation of UV light produced by shower particles. This attenuation depends partially on the amount of aerosols present in the atmosphere at the time of shower observation. Being highly variable, real time measurement of the aerosols light attenuation is accomplished through the use of a central laser facility (CLF) located at the center of the surface array, and in the field of view of the three FDs, as well as, the TALE FD. In this proceeding we will describe the experiment, and the CLF data and analysis, and give results on measured aerosols attenuation, yearly averaged. FD measurements of shower energy and Xmax, involve corrections for atmospheric attenuation due to the presence of aerosols. We discuss the errors introduced into the shower parameters reconstruction due to uncertainty about aerosols attenuation.

scholarly journals Prospects for strangelet detection with large-scale cosmic ray observatories

2016 ◽  
Vol 25 (14) ◽  
pp. 1650103 ◽  
Author(s):  
M. S. Pshirkov
Keyword(s):  
Quark Matter ◽  
High Velocity ◽  
Large Scale ◽  
Cosmic Ray ◽  
High Energy ◽  
Pierre Auger Observatory ◽  
Ultra High Energy ◽  
Telescope Array ◽  
Strange Matter ◽  
The Earth

Quark matter which contains [Formula: see text]-quarks in addition to [Formula: see text]- and [Formula: see text]- could be stable or metastable. In this case, lumps made of this strange matter, called strangelets, could occasionally hit the Earth. When travelling through the atmosphere they would behave not dissimilar to usual high-velocity meteors with only exception that, eventually, strangelets reach the surface. As these encounters are expected to be extremely rare events, very large exposure is needed for their observation. Fluorescence detectors utilized in large ultra-high energy cosmic ray observatories, such as the Pierre Auger observatory and the Telescope Array are well suited for a task of the detection of these events. The flux limits that can be obtained with the Telescope Array fluorescence detectors could be as low as 2.5 × 10−22 cm−2s−1sr−1 which would improve by two orders of magnitude of the strongest present limits obtained from ancient mica crystals.

scholarly journals IS THE ULTRA-HIGH ENERGY COSMIC-RAY EXCESS OBSERVED BY THE TELESCOPE ARRAY CORRELATED WITH ICECUBE NEUTRINOS?

2014 ◽  
Vol 794 (2) ◽  
pp. 126 ◽  
Author(s):  
Ke Fang ◽  
Toshihiro Fujii ◽  
Tim Linden ◽  
Angela V. Olinto
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Telescope Array

scholarly journals Ultra-High-Energy Cosmic-Ray Hotspot Observed with the Telescope Array Surface Detectors

2016 ◽  
Author(s):  
Kazumasa Kawata ◽  
Masaki Fukushima ◽  
Daisuke Ikeda ◽  
Dmitri Ivanov ◽  
Eiji Kido ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Telescope Array

scholarly journals Observation of ultra-high energy cosmic rays with the Telescope Array experiment

2018 ◽  
Vol 182 ◽  
pp. 02122
Author(s):  
Ryuji Takeishi
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Mass Composition ◽  
Ultra High Energy ◽  
Air Showers ◽  
Telescope Array ◽  
High Energy Cosmic Rays ◽  
Fluorescence Light ◽  
Hybrid Detector

The origin of ultra-high energy cosmic rays (UHECRs) has been a longstanding mystery. The Telescope Array (TA) is the largest experiment in the northern hemisphere observing UHECR in Utah, USA. It aims to reveal the origin of UHECR by studying the energy spectrum, mass composition and anisotropy of cosmic rays. TA is a hybrid detector comprised of three air fluorescence stations which measure the fluorescence light induced from cosmic ray extensive air showers, and 507 surface scintillator counters which sample charged particles from air showers on the ground. We present the cosmic ray spectrum observed with the TA experiment. We also discuss our results from measurement of the mass composition. In addition, we present the results from the analysis of anisotropy, including the excess of observed events in a region of the northern sky at the highest energy. Finally, we introduce the TAx4 experiment which quadruples TA, and the TA low energy extension (TALE) experiment.

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