scholarly journals Voyager Measurements of the Mass Composition of Cosmic‐Ray Ne, Mg, Si and S Nuclei

1997 ◽  
Vol 476 (2) ◽  
pp. 766-770 ◽  
Author(s):  
W. R. Webber ◽  
A. Lukasiak ◽  
F. B. McDonald
Keyword(s):  
2019 ◽  
Vol 210 ◽  
pp. 02012
Author(s):  
R. Takeishi

One of the uncertainties in ultrahigh energy cosmic ray (UHECR) observation derives from the hadronic interaction model used for air shower Monte-Carlo (MC) simulations. One may test the hadronic interaction models by comparing the measured number of muons observed at the ground from UHECR induced air showers with the MC prediction. The Telescope Array (TA) is the largest experiment in the northern hemisphere observing UHECR in Utah, USA. It aims to reveal the origin of UHECRs by studying the energy spectrum, mass composition and anisotropy of cosmic rays by utilizing an array of surface detectors (SDs) and fluorescence detectors. We studied muon densities in the UHE extensive air showers by analyzing the signal of TA SD stations for highly inclined showers. On condition that the muons contribute about 65% of the total signal, the number of particles from air showers is typically 1.88 ± 0.08 (stat.) ± 0.42 (syst.) times larger than the MC prediction with the QGSJET II-03 model for proton-induced showers. The same feature was also obtained for other hadronic interaction models, such as QGSJET II-04.


Universe ◽  
2018 ◽  
Vol 4 (11) ◽  
pp. 128 ◽  
Author(s):  
Dariusz Góra ◽  

The Pierre Auger Observatory is the world’s largest operating detection system for the observation of ultra high energy cosmic rays (UHECRs), with energies above 10 17 eV. The detector allows detailed measurements of the energy spectrum, mass composition and arrival directions of primary cosmic rays in the energy range above 10 17 eV. The data collected at the Auger Observatory over the last decade show the suppression of the cosmic ray flux at energies above 4 × 10 19 eV. However, it is still unclear if this suppression is caused by the energy limitation of their sources or by the Greisen–Zatsepin–Kuzmin (GZK) cut-off. In such a case, UHECRs would interact with the microwave background (CMB), so that particles traveling long intergalactic distances could not have energies greater than 5 × 10 19 eV. The other puzzle is the origin of UHECRs. Some clues can be drawn from studying the distribution of their arrival directions. The recently observed dipole anisotropy has an orientation that indicates an extragalactic origin of UHECRs. The Auger surface detector array is also sensitive to showers due to ultra high energy neutrinos of all flavors and photons, and recent neutrino and photon limits provided by the Auger Observatory can constrain models of the cosmogenic neutrino production and exotic scenarios of the UHECRs origin, such as the decays of super heavy, non-standard-model particles. In this paper, the recent results on measurements of the energy spectrum, mass composition and arrival directions of cosmic rays, as well as future prospects are presented.


2019 ◽  
Vol 210 ◽  
pp. 01008
Author(s):  
William Hanlon

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.


2019 ◽  
Vol 210 ◽  
pp. 05011 ◽  
Author(s):  
Tim Huege ◽  

The Auger Engineering Radio Array (AERA) complements the Pierre Auger Observatory with 150 radio-antenna stations measuring in the frequency range from 30 to 80 MHz. With an instrumented area of 17 km2, the array constitutes the largest cosmic-ray radio detector built to date, allowing us to do multi-hybrid measurements of cosmic rays in the energy range of 1017 eV up to several 1018 eV. We give an overview of AERA results and discuss the significance of radio detection for the validation of the energy scale of cosmicray detectors as well as for mass-composition measurements.


2019 ◽  
Vol 216 ◽  
pp. 02004 ◽  
Author(s):  
Fabrizia Canfora

The mass composition of ultra-high-energy cosmic rays plays a key role in the understanding of the origins ofthese rare particles. A composition-sensitive observable is the atmospheric depth at which the air shower reaches the maximum number of particles (Xmax). The Auger Engineering Radio Array (AERA) detects the radio emission inthe 30-80 MHz frequency band from extensive air showers with energies larger than 1017 eV. It consists of more than 150 autonomous radio stations covering an area of about 17 km2. From the distribution of signals measured by the antennas, it is possible to estimate Xmax. In this contribution three independent methods for the estimation of Xmax will be presented.


2004 ◽  
Vol 136 ◽  
pp. 273-281 ◽  
Author(s):  
K.-H. Kampert ◽  
T. Antoni ◽  
W.D. Apel ◽  
F. Badea ◽  
K. Bekk ◽  
...  

2015 ◽  
Vol 754-755 ◽  
pp. 807-811
Author(s):  
A.A. Al-Rubaiee ◽  
Uda Hashim ◽  
Mohd Khairuddin Md Arshad ◽  
A. Rahim Ruslinda ◽  
R.M. Ayub ◽  
...  

The simulation of Cherenkov light Lateral distribution function (LDF) in Extensive Air Showers (EAS) initiated primary particles such as primary calcium, argon, proton iron nuclei, neutron and nitrogen have been performed using CORSIKA program for conditions and configurations of Tunka133 EAS Cherenkov array. The simulation was fulfilled at the high energy range 1014-1016eV for four different zenith angles 0o, 10o, 15oand 30o. The results of the simulated Cherenkov light LDF are compared with the measurements of Tunka133 EAS array for the same particles and energy range mentioned above. This comparison may give the good ability to reconstruct the energy spectrum and mass composition of the primary cosmic ray particles in EAS. The main feature of the given approach consists of the possibility to make a library of Cherenkov light LDF samples which could be utilized for analysis of real events which can be detected with different EAS arrays and reconstruction of the primary cosmic rays energy spectrum and mass composition of EAS particles.


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