scholarly journals Depth of maximum of air-shower profiles: testing the compatibility of measurements performed at the Pierre Auger Observatory and the Telescope Array experiment

2019 ◽  
Vol 210 ◽  
pp. 01009
Author(s):  
Alexey Yushkov ◽  
Jose Bellido ◽  
John Belz ◽  
Vitor de Souza ◽  
William Hanlon ◽  
...  
Keyword(s):  
Quantitative Comparison ◽  
Pierre Auger Observatory ◽  
Array Detector ◽  
Air Showers ◽  
Fluorescence Detector ◽  
Telescope Array ◽  
Longitudinal Development ◽  
Air Shower ◽  
Direct Observations ◽  
Systematic Uncertainties

At the Pierre Auger Observatory and the Telescope Array, the measurements of depths of maximum of airshower profiles, Xmax, are performed using direct observations of the longitudinal development of showers with the help of the fluorescence telescopes. Though the same detection technique is used at both installations, the straightforward comparison of the characteristics of the measured Xmax distributions is not possible due to the different approaches to the analysis of the recorded events. In this work, the Auger – Telescope Array composition working group presents a technique to compare the Xmax measurements from the Auger Observatory and the Telescope Array. Applying this technique the compatibility of the first two moments of the measured Xmax distributions is qualitatively tested for energies 1018.2 eV < E < 1019.0 eV using the recently published Telescope Array data from the Black Rock Mesa and Long Ridge fluorescence detector stations. For a quantitative comparison, simulations of air showers with EPOS-LHC, folded with effects of the Telescope Array detector, are required along with the inclusion in the analysis of the systematic uncertainties in the measurements of Xmax and the energies of the events.

scholarly journals Direct measurement of the muonic content of extensive air showers between $$\mathbf { 2\times 10^{17}}$$ and $$\mathbf {2\times 10^{18}}~$$eV at the Pierre Auger Observatory

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
A. Aab ◽  
◽  
P. Abreu ◽  
M. Aglietta ◽  
J. M. Albury ◽  
...  
Keyword(s):  
Direct Measurement ◽  
High Energy ◽  
Extensive Air Showers ◽  
Pierre Auger Observatory ◽  
Ultra High Energy ◽  
Air Showers ◽  
Fluorescence Detector ◽  
High Energy Cosmic Rays ◽  
Air Shower ◽  
Attenuation Corrected

Abstract The hybrid design of the Pierre Auger Observatory allows for the measurement of the properties of extensive air showers initiated by ultra-high energy cosmic rays with unprecedented precision. By using an array of prototype underground muon detectors, we have performed the first direct measurement, by the Auger Collaboration, of the muon content of air showers between $$2\times 10^{17}$$2×1017 and $$2\times 10^{18}$$2×1018 eV. We have studied the energy evolution of the attenuation-corrected muon density, and compared it to predictions from air shower simulations. The observed densities are found to be larger than those predicted by models. We quantify this discrepancy by combining the measurements from the muon detector with those from the Auger fluorescence detector at $$10^{{17.5}}\, {\mathrm{eV}} $$1017.5eV and $$10^{{18}}\, {\mathrm{eV}} $$1018eV. We find that, for the models to explain the data, an increase in the muon density of $$38\%$$38%$$\pm 4\% (12\%)$$±4%(12%)$$\pm {}^{21\%}_{18\%}$$±18%21% for EPOS-LHC, and of $$50\% (53\%)$$50%(53%)$$\pm 4\% (13\%)$$±4%(13%)$$\pm {}^{23\%}_{20\%}$$±20%23% for QGSJetII-04, is respectively needed.

scholarly journals The Auger@TA Project: Phase II Progress and Plans

2019 ◽  
Vol 210 ◽  
pp. 05004 ◽  
Author(s):  
Corbin Covault ◽  
Toshihiro Fujii ◽  
Robert Halliday ◽  
Jeffrey Johnsen ◽  
Ryan Lorek ◽  
...  
Keyword(s):  
Phase Ii ◽  
Pierre Auger Observatory ◽  
Air Showers ◽  
Telescope Array ◽  
Air Shower ◽  
Surface Detector ◽  
Laser Facility ◽  
Micro Array ◽  
Water Tanks ◽  
Data Calibration

The Auger@TA project is a combined effort involving members of both the Pierre Auger Observatory and the Telescope Array experiment (TA) to cross-calibrate detectors and compare results on air showers detected at one location. We have recently reported results from Phase I of the project, during which we collected and presented data from two Auger water Cherenkov surface detector stations deployed into the TA experiment near the Central Laser Facility. For Phase II, we will deploy a micro-array of six or seven single-PMT Auger surface detector stations co-located with TA scintillator surface detector stations. The Auger micro-array will trigger and collect data independently from the TA allowing for a complete end-to-end comparison of detector data, calibration, and reconstructed event quantities on a shower-by-shower basis between the TA and Auger detector systems. We describe progress towards development of the micro-array for Phase II including the preparation of surface detector water tanks, station electronics, wireless communications, triggers, and data acquisition. We also outline plans for deploying the Auger@TA micro-array into the TA experiment in 2019 with preliminary estimates for coincident air-shower rates.

scholarly journals The use of aerosol data in Auger Fluorescence Detector analysis

2019 ◽  
Vol 197 ◽  
pp. 01004
Author(s):  
Bruce R. Dawson
Keyword(s):  
Light Attenuation ◽  
Cosmic Ray ◽  
Primary Energy ◽  
Air Showers ◽  
Fluorescence Detector ◽  
Air Shower ◽  
Systematic Uncertainties ◽  
Surface Detector ◽  
Shower Maximum ◽  
Fluorescence Light

The Pierre Auger Observatory’s Fluorescence Detector (FD) consists of 27 telescopes arranged in four sites around the perimeter of the 3000 square kilometre Surface Detector (SD). Cosmic ray extensive air showers are viewed via the nitrogen fluorescence light they induce in the atmosphere. Careful treatment of light attenuation processes must be made, especially given that some showers are viewed at distances in excess of 30 km. Of particular importance is the attenuation due to scattering by aerosol particles, a challenging topic given that aerosol concentrations can vary on time-scales of hours. At the Auger Observatory, the vertical distribution of aerosols is measured hourly with a series of bi-static lidar systems (consisting of central laser facilities and each of the FD sites), and three times per night with a Raman lidar system. In this contribution we describe the use of aerosol profiles in the analysis of air shower data, in particular in the estimation of the cosmic ray primary energy, and the depth of shower maximum, Xmax. We also demonstrate how statistical and systematic uncertainties in the aerosol concentrations propagate through to a contribution to energy and Xmax uncertainties.

scholarly journals Determination of the invisible energy of extensive air showers from the data collected at Pierre Auger Observatory

2019 ◽  
Vol 210 ◽  
pp. 02010
Author(s):  
Analisa G. Mariazzi ◽  
Keyword(s):  
High Energy ◽  
Primary Energy ◽  
Energy Scale ◽  
Extensive Air Showers ◽  
Pierre Auger Observatory ◽  
Mass Composition ◽  
Air Showers ◽  
Systematic Uncertainties ◽  
Muon Production ◽  
The Invisible

In order to get the primary energy of cosmic rays from their extensive air showers using the fluorescence detection technique, the invisible energy should be added to the measured calorimetric energy. The invisible energy is the energy carried away by particles that do not deposit all their energy in the atmosphere. It has traditionally been calculated using Monte Carlo simulations that are dependent on the assumed primary particle mass and on model predictions for neutrino and muon production. In this work the invisible energy is obtained directly from events detected by the Pierre Auger Observatory. The method applied is based on the correlation of the measurements of the muon number at the ground with the invisible energy of the showers. By using it, the systematic uncertainties related to the unknown mass composition and to the high energy hadronic interaction models are significantly reduced, improving in this way the estimation of the energy scale of the Observatory.

scholarly journals Telescope Array Experiment

2019 ◽  
Vol 208 ◽  
pp. 08002
Author(s):  
Shoichi Ogio
Keyword(s):  
Cosmic Ray ◽  
Low Energy ◽  
Current Status ◽  
Future Prospects ◽  
Fluorescence Detector ◽  
Telescope Array ◽  
Air Shower ◽  
Primary Particles ◽  
Shower Array ◽  
Air Shower Array

The Telescope Array is the largest hybrid cosmic ray detector in the Northern hemisphere designed to measure primary particles in 4 PeV to 100 EeV range. The main TA detector consists of an air shower array of 507 plastic scintillation counters on a 1.2 km square grid and fluorescence detectors at three stations overlooking the sky above the air shower array. The experiment and its recent measurements - spectrum, composition, and anisotropy - is reviewed. Recently the construction of the TA Low energy Extension (TALE) detector, which consists of an additional fluorescence detector and an infill array, was finished. TALE lowers the energy threshold of TA down to 4 PeV. We are also constructing the TAx4 detector to increase statistics in particular at the highest energies. The current status and the future prospects of these new TAx4 experiments is reported.

scholarly journals Atmospheric aerosol attenuation effect on FD data analysis at the Pierre Auger Observatory

2019 ◽  
Vol 210 ◽  
pp. 05008
Author(s):  
Laura Valore ◽  
Keyword(s):  
Atmospheric Aerosol ◽  
Uv Light ◽  
Pierre Auger Observatory ◽  
Event Analysis ◽  
Air Showers ◽  
Fluorescence Detector ◽  
Attenuation Effect ◽  
Laser Facility ◽  
Shower Maximum ◽  
Light Profiles

The atmospheric aerosol monitoring system of the Pierre Auger Observatory has been operating smoothly since 2004. Two laser facilities (Central Laser Facility, CLF and eXtreme Laser Facility, XLF) fire sets of 50 shots four times per hour during FD shifts to measure the highly variable hourly aerosol attenuation to correct the longitudinal UV light profiles of the Extensive Air Showers detected by the Fluorescence Detector. Hourly aerosol attenuation loads (Vertical Aerosol Optical Depth) are used to correct the measured profiles. Two techniques are used to determine the aerosol profiles, which have been proven to be fully compatible. The uncertainty in the VAOD profiles measured consequently leads to an uncertainty on the energy and on the estimation of the depth at the maximum development of a shower (Xmax) of the event in analysis. To prove the validity of the aerosol attenuation measurements used in FD event analysis, the flatness of the ratio of reconstructed SD to FD energy as a function of the aerosol transmission to the depth of shower maximum has been verified.

scholarly journals Study of muons from ultrahigh energy cosmic ray air showers measured with the Telescope Array experiment

2019 ◽  
Vol 210 ◽  
pp. 02012
Author(s):  
R. Takeishi
Keyword(s):  
Interaction Model ◽  
Cosmic Ray ◽  
Mass Composition ◽  
Ultrahigh Energy ◽  
Air Showers ◽  
Hadronic Interaction ◽  
Telescope Array ◽  
Interaction Models ◽  
Air Shower ◽  
Number Of Particles

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.

scholarly journals A next-generation ground array for the detection of ultrahigh-energy cosmic rays: the Fluorescence detector Array of Single-pixel Telescopes (FAST)

2019 ◽  
Vol 210 ◽  
pp. 06003
Author(s):  
Toshihiro Fujii ◽  
Max Malacari ◽  
Justin Albury ◽  
Jose A. Bellido ◽  
Ladislav Chytka ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Full Scale ◽  
Pierre Auger Observatory ◽  
Detector Array ◽  
Ultrahigh Energy ◽  
Next Generation ◽  
Fluorescence Detector ◽  
Telescope Array ◽  
Ultrahigh Energy Cosmic Rays ◽  
Single Pixel

The origin and nature of ultrahigh-energy cosmic rays (UHECRs) is one of the most intriguing and important mysteries in astroparticle physics. The two largest observatories currently in operation, the Telescope Array Experiment in central Utah, USA, and the Pierre Auger Observatory in western Argentina, have been steadily observing UHECRs in both hemispheres for over a decade. We highlight the latest results from both of these experiments, and address the requirements for a next-generation UHECR observatory. The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for a next-generation UHECR observa-tory, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays with an unprecedented aperture. We have developed a full-scale prototype consisting of four 200 mm photomultiplier-tubes at the focus of a segmented mirror of 1.6 m in diameter. Over the last three years, we installed three such prototypes at the Black Rock Mesa site of the Telescope Array Experiment. These telescopes have been steadily taking data since installation. We report on preliminary results of the full-scale FAST prototypes, including measurements of distant ultraviolet lasers and UHECRs. Futhermore, we discuss our plan to install an additional identical FAST prototype at the Pierre Auger Observatory. Possible benefits to the Telescope Array and the Pierre Auger Observatory include a comparison of the transparency of the atmosphere above both experiments, a study of the systematic uncertainty associated with their existing fluorescence detectors, and a cross-calibration of their energy and Xmax scales.

SIMULATIONS OF EXTENSIVE AIR SHOWERS FOR THE ESTIMATION OF THE NUMBER OF PHOTOELECTRONS OF A SETUP OF P. AUGER FLUORESCENCE DETECTOR

2008 ◽  
Vol 23 (02) ◽  
pp. 259-265
Author(s):  
A. GERANIOS ◽  
E. FOKITIS ◽  
S. MALTEZOS ◽  
K. PATRINOS ◽  
H. ROZAKI-MAVROULI
Keyword(s):  
Detection Efficiency ◽  
Optical Filter ◽  
Angle Of Incidence ◽  
Pixel Detector ◽  
Air Showers ◽  
Fluorescence Detector ◽  
Extensive Air Shower ◽  
Air Shower ◽  
Electrons And Positrons ◽  
Detector Geometry

The efficiency of a pixel detector using optical UV filters is determined in this work. Based on the Auger fluorescence detector geometry, we have calculated the overall efficiency of the pixel detector using an appropriate method that takes into account the particular spectral functions and the dependence on the angle of incidence of the optical filter used. Assuming extensive air shower (EAS) events developed with various inclinations generated by AIRES code, we calculated the number of electrons and positrons produced during the development of the EAS's. The detection efficiency of the pixel detector is taken into account in estimating the recorded signal (number of photoelectrons) for two sets of EAS simulations, corresponding to protons and iron nuclei, as primary particles.

scholarly journals Overview of the Auger@TA project and preliminary results from Phase I

2019 ◽  
Vol 210 ◽  
pp. 05002
Author(s):  
Fred Sarazin ◽  
Corbin Covault ◽  
Toshihiro Fujii ◽  
Robert Halliday ◽  
Jeffrey Johnsen ◽  
...  
Keyword(s):  
Phase I ◽  
Pierre Auger Observatory ◽  
Gear Up ◽  
Air Showers ◽  
Telescope Array ◽  
Surface Detector ◽  
First Results ◽  
Micro Array ◽  
Cross Calibration

We report on the first results of a unique in-situ experimental cross-calibration effort of the surface detector of the Pierre Auger Observatory and of the Telescope Array experiment (Auger@TA). In the first phase of Auger@TA, we performed surface detector station-to-station comparisons for a collection of extensive air showers landing near the experimental setup and detected by Telescope Array. Beyond the deduced cross-calibration curve between the Water-Cherenkov-based Auger and Scintillator-based TA Surface Detector stations, we also investigate the consistency of their response for individual reconstructed showers. The dataset is currently too small to draw firm conclusions as-of-yet. Hence, phase I data taking will continue even as we gear up for the deployment of an Auger micro-array within Telescope Array as part of Phase II of this work.

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