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1.
Education, Outreach and Public Relations of the Pierre Auger Observatory
Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Darko Veberič, Marta Trini, Samo Stanič, Ahmed Saleh, Gašper Kukec Mezek, Andrej Filipčič, Charles Timmermans, 2015, objavljeni znanstveni prispevek na konferenci

Opis: The scale and scope of the physics studied at the Pierre Auger Observatory continue to offer significant opportunities for original outreach work. Education, outreach and public relations of the Auger Collaboration are coordinated in a dedicated task whose goals are to encourage and support a wide range of efforts that link schools and the public with the Auger scientists and the science of cosmic rays, particle physics, and associated technologies. We focus on the impact of the Collaboration in Mendoza Province, Argentina and beyond. The Auger Visitor Center in Malargüe has hosted over 95,000 visitors since 2001, and a fifth Collaboration-sponsored science fair was held on the Observatory campus in November 2014. The Rural Schools Program, which is run by Observatory staff and which brings cosmic-ray science and infrastructure improvements to remote schools, continues to broaden its reach. Numerous online resources, video documentaries, and animations of extensive air showers have been created for wide public release. Increasingly, collaborators draw on these resources to develop Auger related displays and outreach events at their institutions and in public settings to disseminate the science and successes of the Observatory worldwide. We also highlight education and outreach activities associated with the planned upgrade of the Observatory’s detector systems and future physics goals.
Najdeno v: ključnih besedah
Povzetek najdenega: ...with the Auger scientists and the science of cosmic rays, particle physics, and associated technologies. We...
Ključne besede: Pierre Auger Observatory, cosmic rays physics, education, outreach, public relations
Objavljeno: 03.03.2016; Ogledov: 2016; Prenosov: 111
.pdf Polno besedilo (4,12 MB)

2.
An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources
Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Darko Veberič, Marta Trini, Samo Stanič, Ahmed Saleh, Gašper Kukec Mezek, Andrej Filipčič, A. Aab, 2018, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: ...astroparticle physics, cosmic rays, active galaxies, starburst galaxies, data...
Ključne besede: astroparticle physics, cosmic rays, active galaxies, starburst galaxies, data analysis methods
Objavljeno: 14.02.2018; Ogledov: 1024; Prenosov: 0
.pdf Polno besedilo (2,83 MB)

3.
Multi-Messenger Physics With the Pierre Auger Observatory
Karl-Heinz Kampert, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: ...Pierre Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics and...
Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics and astrophysics
Objavljeno: 06.05.2019; Ogledov: 679; Prenosov: 42
.pdf Polno besedilo (2,46 MB)

4.
Mass composition of ultra-high energy cosmic rays at the Pierre Auger Observatory
Gašper Kukec Mezek, 2019, doktorska disertacija

Opis: Cosmic rays with energies above 10^18 eV, usually referred to as ultra-high energy cosmic rays (UHECR), have been a mystery from the moment they have been discovered. Although we have now more information on their extragalactic origin, their direct sources still remain hidden due to deviations caused by galactic magnetic fields. Another mystery, apart from their production sites, is their nature. Their mass composition, still uncertain at these energies, would give us a better understanding on their production, acceleration, propagation and capacity to produce extensive air showers in the Earth's atmosphere. Mass composition studies of UHECR try to determine their nature from the difference in development of their extensive air showers. In this work, observational parameters from the hybrid detection system of the Pierre Auger Observatory are used in a multivariate analysis to obtain the mass composition of UHECR. The multivariate analysis (MVA) approach combines a number of mass composition sensitive variables and tries to improve the separation between different UHECR particle masses. Simulated distributions of different primary particles are fitted to measured observable distributions in order to determine individual elemental fractions of the composition. When including observables from the surface detector, we find a discrepancy in the estimated mass composition between a mixed simulation sample and the Pierre Auger data. Our analysis results from the Pierre Auger data are to a great degree independent on hadronic interaction models. Although they differ at higher primary masses, the different models are more consistent, when combining fractions of oxygen and iron. Compared to previously published results, the systematic uncertainty from hadronic interaction models is roughly four times smaller. Our analysis reports a predominantly heavy composition of UHECR, with more than a 50% fraction of oxygen and iron at low energies. The composition is then becoming heavier with increasing energy, with a fraction of oxygen and iron above 80% at the highest energies.
Najdeno v: ključnih besedah
Povzetek najdenega: ...astroparticle physics, ultra-high energy cosmic rays, extensive air showers,...
Ključne besede: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, machine learning, multivariate analysis
Objavljeno: 03.04.2019; Ogledov: 1093; Prenosov: 62
.pdf Polno besedilo (17,53 MB)

5.
Mass composition of cosmic rays with energies from 10^17.2 eV to 10^20 eV using surface and fluorescence detectors of the Pierre Auger Observatory
Gašper Kukec Mezek, 2018, objavljeni znanstveni prispevek na konferenci

Opis: Ultra-high-energy cosmic rays (UHECRs) are highly energetic particles with EeV energies, exceeding the capabilities of man-made colliders. They hold information on extreme astrophysical processes that create them and the medium they traverse on their way towards Earth. However, their mass composition at such energies is still unclear, because data interpretation depends on our choice of high energy hadronic interaction models. With its hybrid detection method, the Pierre Auger Observatory has the possibility to detect extensive air showers with an array of surface water-Cherenkov stations (SD) and fluorescence telescopes (FD). We present recent mass composition results from the Pierre Auger Collaboration using observational parameters from SD and FD measurements. Using the full dataset of the Pierre Auger Observatory, implications on composition can be made for energies above 10^17.2 eV.
Najdeno v: ključnih besedah
Povzetek najdenega: ...astroparticle physics, ultra-high energy cosmic rays, extensive air showers,...
Ključne besede: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, fluorescence telescopes, water-Cherenkov stations
Objavljeno: 24.05.2019; Ogledov: 785; Prenosov: 43
.pdf Polno besedilo (573,00 KB)

6.
Evidence of Intermediate-scale Energy Spectrum Anisotropy of Cosmic Rays E ≥ 10^19.2 eV with the Telescope Array Surface Detector
J. P. Lundquist, R.U. Abbasi, 2018, izvirni znanstveni članek

Opis: Evidence for an intermediate-scale energy spectrum anisotropy has been found in the arrival directions of ultra-high energy cosmic rays for energies greater than 10^19.2 eV in the northern hemisphere using 7 years of Telescope Array surface detector data. A relative energy distribution test is done comparing events inside oversampled spherical caps of equal exposure, to those outside, using the Poisson likelihood ratio. The center of maximum significance is at 9h16m, 45°, and has a deficit of events with energies 10^19.2 ≤ E < 10^19.75 eV and an excess for E ≥ 10^19.75 eV. The post-trial probability of this energy anisotropy, appearing by chance anywhere on an isotropic sky, is found by Monte Carlo simulation to be 9 × 10−5 (3.74σ global).
Najdeno v: ključnih besedah
Povzetek najdenega: ...astroparticle physics, cosmic rays, anisotropy, large-scale structure of universe...
Ključne besede: astroparticle physics, cosmic rays, anisotropy, large-scale structure of universe
Objavljeno: 24.04.2020; Ogledov: 434; Prenosov: 15
.pdf Polno besedilo (1,43 MB)

7.
Testing a Reported Correlation between Arrival Directions of Ultra-high-energy Cosmic Rays and a Flux Pattern from nearby Starburst Galaxies using Telescope Array Data
J. P. Lundquist, R.U. Abbasi, 2018, izvirni znanstveni članek

Opis: The Pierre Auger Collaboration (Auger) recently reported a correlation between the arrival directions of cosmic rays with energies above 39 EeV and the flux pattern of 23 nearby starburst galaxies (SBGs). In this Letter, we tested the same hypothesis using cosmic rays detected by the Telescope Array experiment (TA) in the 9-year period from May 2008 to May 2017. Unlike the Auger analysis, we did not optimize the parameter values but kept them fixed to the best-fit values found by Auger, namely 9.7% for the anisotropic fraction of cosmic rays assumed to originate from the SBGs in the list and 12.9◦ for the angular scale of the correlations. The energy threshold we adopted is 43 EeV, corresponding to 39 EeV in Auger when taking into account the energy-scale difference between two experiments. We find that the TA data is compatible with isotropy to within 1.1σ and with the Auger result to within 1.4σ, meaning that it is not capable to discriminate between these two hypotheses.
Najdeno v: ključnih besedah
Povzetek najdenega: ...astroparticle physics, cosmic rays, galaxies: starburst, methods: data analysis...
Ključne besede: astroparticle physics, cosmic rays, galaxies: starburst, methods: data analysis
Objavljeno: 27.04.2020; Ogledov: 373; Prenosov: 23
.pdf Polno besedilo (700,72 KB)

8.
Depth of Ultra High Energy Cosmic Ray Induced Air Shower Maxima Measured by the Telescope Array Black Rock and Long Ridge FADC Fluorescence Detectors and Surface Array in Hybrid Mode
J. P. Lundquist, R.U. Abbasi, 2018, izvirni znanstveni članek

Opis: The Telescope Array (TA) observatory utilizes fluorescence detectors and surface detectors (SDs) to observe air showers produced by ultra high energy cosmic rays in Earth's atmosphere. Cosmic-ray events observed in this way are termed hybrid data. The depth of air shower maximum is related to the mass of the primary particle that generates the shower. This paper reports on shower maxima data collected over 8.5 yr using the Black Rock Mesa and Long Ridge fluorescence detectors in conjunction with the array of SDs. We compare the means and standard deviations of the observed Xmax distributions with Monte Carlo Xmax distributions of unmixed protons, helium, nitrogen, and iron, all generated using the QGSJet II-04 hadronic model. We also perform an unbinned maximum likelihood test of the observed data, which is subjected to variable systematic shifting of the data Xmax distributions to allow us to test the full distributions, and compare them to the Monte Carlo to see which elements are not compatible with the observed data. For all energy bins, QGSJet II-04 protons are found to be compatible with TA hybrid data at the 95% confidence level after some systematic Xmax shifting of the data. Three other QGSJet II-04 elements are found to be compatible using the same test procedure in an energy range limited to the highest energies where data statistics are sparse.
Najdeno v: ključnih besedah
Povzetek najdenega: ...showers produced by ultra high energy cosmic rays in Earth's atmosphere. Cosmic-ray events observed in... ...acceleration of particles,astrochemistry,astroparticle physics, cosmic rays, elementary particles, UHECR, composition...
Ključne besede: acceleration of particles, astrochemistry, astroparticle physics, cosmic rays, elementary particles, UHECR, composition
Objavljeno: 27.04.2020; Ogledov: 352; Prenosov: 0
.pdf Polno besedilo (5,52 MB)

9.
Measurement of the proton-air cross section with Telescope Array’s Middle Drum detector and surface array in hybrid mode
J. P. Lundquist, R.U. Abbasi, 2015, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: ... Cosmic Rays, proton cross-section, ultra-high energy, particle physics...
Ključne besede: Cosmic Rays, proton cross-section, ultra-high energy, particle physics
Objavljeno: 27.04.2020; Ogledov: 350; Prenosov: 0
.pdf Polno besedilo (409,81 KB)

10.
Energy response of ISS-CREAM calorimeter with attenuation effect
J. P. Lundquist, H.G. Zhang, 2020, drugi članki ali sestavki

Opis: The NASA mission, Cosmic Ray Energetic And Mass experiment for the International Space Station (ISS-CREAM) is to measure individual cosmic-ray particle energy spectra from protons to iron nuclei, with an energy range from ~1 TeV to the so-called "knee", near 1015eV. Energies of cosmic-ray particles are measured from electromagnetic showers induced by particles in the calorimeter. As a pioneer mission, the balloon-borne CREAM instrument has successfully flown seven times over the Antarctica for a cumulative exposure of 191 days. The CREAM calorimeter has shown sufficient capability to measure energies of cosmic-ray particles by capturing the electromagnetic shower profile within the interested energy range. The ISS-CREAM calorimeter is expected to have a similar performance and, before it was launched, an engineering-unit calorimeter was shipped to CERN for a full beam test. The full performance test includes position, energy, and angle scans of electron and pion beams together with a high voltage scan for calibration and characterization. In addition to the regular analysis for performance test, we also applied an additional step to generate the universal energy responses by correcting the attenuation effect in the calorimeter readout. The general energy responses could be obtained after shifting the incident beam positions to a reference position near the center of the calorimeter, which provided improved energy resolutions. The result of this analysis will be used to determine the incident energies of the cosmic-ray particles in the flight data.
Najdeno v: ključnih besedah
Povzetek najdenega: ...The NASA mission, Cosmic Ray Energetic And Mass experiment for the... ...cosmic rays, high-energy, particle physics, detectors...
Ključne besede: cosmic rays, high-energy, particle physics, detectors
Objavljeno: 29.04.2020; Ogledov: 302; Prenosov: 14
.pdf Polno besedilo (2,54 MB)

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