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121.
Follow-up Search for UHE Photons from Gravitational Wave Sources with the Pierre Auger Observatory
P. Ruehl, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, objavljeni znanstveni prispevek na konferenci

Opis: Multimessenger astronomy has become increasingly important during the past decade. Some astronomical objects have already been successfully observed in the light of multiple messenger signals, allowing for a much deeper understanding of their physical properties. The Pierre Auger Observatory has taken part in multimessenger astronomy with an exhaustive exploration of the ultra-high-energy sky. In this contribution, for the first time, a search for UHE photons from the sources of gravitational waves is presented. Interactions with the cosmic background radiation fields are expected to attenuate any possible flux of ultra-high-energy photons from distant sources and a non-negligible background of air shower events with hadronic origin makes an unambiguous identification of primary photons a challenging task. In the analysis presented here, a selection strategy is applied to both GW sources and air shower events aiming to provide maximum sensitivity to a possible photon signal. At the same time, a window is kept open for hypothetical new-physics processes, which might allow for much larger interaction lengths of photons in the extragalactic medium. Preliminary results on the UHE photon fluence from a selection of GW sources, including the binary neutron star merger GW170817 are presented.
Ključne besede: Pierre Auger Observatory, indirect detection, fluorescence detection, ultra-high energy, photons, cosmic rays, anisotropy, gravitational waves, multimessenger
Objavljeno v RUNG: 29.09.2023; Ogledov: 527; Prenosov: 6
.pdf Celotno besedilo (940,08 KB)
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122.
Performance and simulation of the surface detector array of the TAx4 experiment
K. Fujisue, Jon Paul Lundquist, 2022, objavljeni znanstveni prispevek na konferenci

Opis: The TAx4 experiment is a project to observe highest energy cosmic rays by expanding the detectionarea of the Telescope Array (TA) experiment with newly constructed surface detectors (SDs) andfluorescence detectors (FDs). New SDs are arranged in a square grid with 2.08 km spacing atthe north east and south east of the TA SD array. We use CORSIKA simulations and implementthe calibration data of the new SDs to calculate the performance of the new SDs. We comparethe data with the simulation and validate the performance of the SDs. The comparison and theperformance will be shown in the presentation.
Ključne besede: Telescope Array, TAx4, indirect detection, ground array, surface detection, ultra-high energy, cosmic rays, CORSIKA
Objavljeno v RUNG: 29.09.2023; Ogledov: 521; Prenosov: 5
.pdf Celotno besedilo (3,16 MB)
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123.
Science with the Global Cosmic-ray Observatory (GCOS)
Rafael Alves Batista, M. Ahlers, Pedro Assis, Markus Gottfried Battisti, J. A. Bellido, S. Bhatnagar, K. Bismark, Teresa Bister, Martina Boháčová, Serguei Vorobiov, 2023, objavljeni znanstveni prispevek na konferenci

Opis: The Global Cosmic-ray Observatory (GCOS) is a proposed large-scale observatory for studying ultra-high-energy cosmic particles, including ultra-high-energy cosmic rays (UHECRs), photons, and neutrinos. Its primary goal is to characterise the properties of the highest-energy particles in Nature with unprecedented accuracy, and to identify their elusive sources. With an aperture at least a ten-fold larger than existing observatories, this next-generation facility should start operating after 2030, when present-day detectors will gradually cease their activities. Here we briefly review the scientific case motivating GCOS. We present the status of the project, preliminary ideas for its design, and some estimates of its capabilities.
Ključne besede: ultra-high-energy cosmic rays, UHE photons, UHE neutrinos, the Global Cosmic-ray Observatory project
Objavljeno v RUNG: 27.09.2023; Ogledov: 819; Prenosov: 5
.pdf Celotno besedilo (692,24 KB)
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124.
Outreach activities at the Pierre Auger Observatory
K.S. Caballero-Mora, Jon Paul Lundquist, 2022, objavljeni znanstveni prispevek na konferenci

Opis: The Pierre Auger Observatory, sited in Malargüe, Argentina, is the largest observatory available for measuring ultra-high-energy cosmic rays (UHECR). The Auger Collaboration has measured and analysed an unprecedented number of UHECRs. Along with making important scientific discoveries, for example, the demonstration that cosmic rays above 8 EeV are of extragalactic origin and the observation of a new feature in the energy spectrum at around 13 EeV, outreach work has been carried out across the 18 participating countries and online. This program ranges from talks to a varied audience, to the creation of a local Visitor Center, which attracts 8000 visitors annually, to initiating masterclasses. Permanent and temporary exhibitions have been prepared both in reality and virtually. Science fairs for elementary- and high-school students have been organised, together with activities associated with interesting phenomena such as eclipses. In addition, we participate in international events such as the International Cosmic Day, Frontiers from H2020, and the International Day of Women and Girls in Science. Part of the Collaboration website is aimed at the general public. Here the most recent articles published are summarised. Thus the Collaboration informs people about work in our field, which may seem remote from everyday life. Furthermore, the Auger Observatory has been a seed for scientific and technological activities in and around Malargüe. Different outreach ventures that already have been implemented and others which are foreseen will be described.
Ključne besede: Pierre Auger Observatory, indirect detection, ultra-high energy, cosmic rays, outreach, open data
Objavljeno v RUNG: 26.09.2023; Ogledov: 558; Prenosov: 5
.pdf Celotno besedilo (7,94 MB)
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125.
Highlights from the Telescope Array experiment
Grigory I. Rubtsov, R. U. Abbasi, T. Abu-Zayyad, M. Allen, Yasuhiko Arai, R. Arimura, E. Barcikowski, J. W. Belz, Douglas R. Bergman, Jon Paul Lundquist, 2022, objavljeni znanstveni prispevek na konferenci (vabljeno predavanje)

Opis: The Telescope Array (TA) is the largest cosmic ray observatory in the Northern Hemisphere. It is designed to measure the properties of cosmic rays over a wide range of energies. TA with it's low energy extension (TALE) observe cosmic-ray induced extensive air showers between 2 PeV and 100 EeV in hybrid mode using multiple instruments, including an array of scintillator detectors at the Earth's surface and telescopes to measure the fluorescence and Cerenkov light. The statistics at the highest energies is being enhanced with the ongoing construction of the TAx4 experiment which will quadruple the surface area of the detector. We review the present status of the experiments and most recent physics results on the cosmic ray anisotropy, chemical composition and energy spectrum. Notable highlights include a new feature in the energy spectrum at about 10^19.2 eV, and a new clustering of events in the direction of Perseus-Pisces supercluster above this energy. We also report on updated diffuse photon flux limits and new spectrum and composition results in the lower energy range from the TALE extension.
Ključne besede: Telescope Array, TALE, low energy extension, TAx4, indirect detection, hybrid detection, ground array, fluorescence detection, Cherenkov light, ultra-high energy, cosmic rays, energy spectrum, composition, anisotropy
Objavljeno v RUNG: 26.09.2023; Ogledov: 601; Prenosov: 5
.pdf Celotno besedilo (6,75 MB)
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126.
Analysis Result of the High-Energy Cosmic-Ray Proton Spectrum from the ISS-CREAM Experiment
G. Choi, Jon Paul Lundquist, 2022, objavljeni znanstveni prispevek na konferenci

Opis: The Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) experiment successfully recorded the data for about 539 days from August 2017 to February 2019. In this talk, we report the measurement of the cosmic-ray proton energy spectrum from the ISS-CREAM experiment in the energy range of 2.5 TeV - 650 TeV. For the analysis, we used the silicon charge detector (SCD) placed at the top of the ISS-CREAM payload to identify the incoming cosmic-ray charge. The SCD is finely segmented to minimize charge misidentification due to backscatter effects. The four-layer SCD consists of 10,752 silicon pixels, each of which is 1.37×1.57×0.05 cm^3 in size. The calorimeter (CAL) consists of 20 layers of tungsten/scintillating fibers preceded by carbon targets. It provided cosmic-ray tracking, energy determination, and the high-energy trigger. The Top and Bottom Counting detectors (T/BCD) are above and below the CAL, respectively, and provided the low energy trigger. Each T/BCD is composed of an array of 20×20 photodiodes on plastic scintillators. The measured proton spectral index of 2.67±0.02 between 2.5 and 12.5 TeV is consistent with prior CREAM measurements. The spectrum softens above ∼10 TeV consistent with the bump-like structure as reported by CREAM-I+III, DAMPE, and NUCLEON, but ISS-CREAM extends measurements to higher energies than those prior measurement
Ključne besede: ISS-CREAM, silicon charge detector, calorimeter, direct detection, cosmic rays, protons, energy spectrum
Objavljeno v RUNG: 26.09.2023; Ogledov: 556; Prenosov: 6
.pdf Celotno besedilo (2,06 MB)
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127.
Results from the Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) experiment
E.S. Seo, Jon Paul Lundquist, 2022, objavljeni znanstveni prispevek na konferenci

Opis: The Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) experiment took high-energy cosmic ray data for 539 days after its successful installation on the ISS in August 2017. The ISS-CREAM instrument is configured with complementary particle detectors capable of measuring elemental spectra for Z = 1 - 26 nuclei in the energy range 10^12 – 10^15 eV; as well as electrons at multi-TeV energies. The goal is to understand cosmic ray origin, acceleration, and propagation by extending direct measurements of cosmic rays to energies that overlap the energy region of air showers measurements. The four layers of finely segmented Silicon Charge Detectors provide precise charge measurements. They have been designed to minimize hits of accompanying backscattered particles in the same segment as the incident cosmic ray particle to avoid charge misidentification. The sampling tungsten/scintillating-fiber calorimeter, which is identical to the calorimeter for prior CREAM balloon flights, provides energy measurements. In addition, scintillator-based Top and Bottom Counting Detectors distinguish electrons from nuclei. Our analysis indicates that the data extend well above 100 TeV. Recent results from the ongoing analysis are presented.
Ključne besede: ISS-CREAM, silicon charge detector, calorimeter, direct detection, cosmic rays, electrons, energy spectrum, composition
Objavljeno v RUNG: 26.09.2023; Ogledov: 623; Prenosov: 6
.pdf Celotno besedilo (901,39 KB)
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128.
Cosmic-ray Heavy Nuclei Spectra Using the ISS-CREAM Instrument
S.C. Kang, Jon Paul Lundquist, 2022, objavljeni znanstveni prispevek na konferenci

Opis: Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) was designed to study high-energy cosmic rays up to PeV and recorded data from August 22nd, 2017 to February 12th, 2019 on the ISS. In this analysis, the Silicon Charge Detector (SCD), CALorimeter (CAL), and Top and Bottom Counting Detectors (TCD/BCD) are used. The SCD is composed of four layers and provides the measurement of cosmic-ray charges with a resolution of ∼0.2e. The CAL comprises 20 interleaved tungsten plates and scintillators, measures the incident cosmic-ray particles' energies, and provides a high energy trigger. The TCD/BCDs consist of photodiode arrays and plastic scintillators and provide a low-energy trigger. In this analysis, the SCD top layer is used for charge determination. Here, we present the heavy nuclei analysis using the ISS-CREAM instrument.
Ključne besede: ISS-CREAM, silicon charge detector, calorimeter, direct detection, heavy nuclei, cosmic rays, energy spectrum, composition
Objavljeno v RUNG: 26.09.2023; Ogledov: 525; Prenosov: 5
.pdf Celotno besedilo (1,82 MB)
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129.
Beam Test Results of the ISS-CREAM Calorimeter
H.G. Zhang, Jon Paul Lundquist, 2022, objavljeni znanstveni prispevek na konferenci

Opis: The Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) was installed on the ISS to measure high-energy cosmic-ray elemental spectra for the charge range Z=1 to 26. The ISS-CREAM instrument includes a tungsten scintillating-fiber calorimeter preceded by carbon targets for energy measurements. The carbon targets induces hadronic interactions, and showers of secondary particles develop in the calorimeter. The calorimeter was calibrated with electron beams at CERN. This beam test included position, energy, and angle scans of electron and pion beams together with a high-voltage scan for calibration and characterization. Additionally, an attenuation effect in the scintillating fibers was studied. In this paper, beam test results, including corrections for the attenuation effect, are presented.
Ključne besede: ISS-CREAM, calorimeter, particle accelerator, CERN, electron beam, direct detection, cosmic rays, energy spectrum, composition
Objavljeno v RUNG: 26.09.2023; Ogledov: 579; Prenosov: 4
.pdf Celotno besedilo (1003,73 KB)
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130.
Performance study update of observations in divergent mode for the Cherenkov Telescope Array
A. Donini, Saptashwa Bhattacharyya, Judit Pérez Romero, Samo Stanič, Veronika Vodeb, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Miha Živec, 2023, objavljeni znanstveni prispevek na konferenci

Opis: Due to the limited field of view (FoV) of Cherenkov telescopes, the time needed to achieve target sensitivity for surveys of the extragalactic and Galactic sky is large. To optimize the time spent to perform such surveys, a so-called “divergent mode” of the Cherenkov Telescope Array Observatory (CTAO) was proposed as an alternative observation strategy to the traditional parallel pointing. In the divergent mode, each telescope points to a position in the sky that is slightly offset, in the outward direction, from the original center of the field of view. This bring the advantage of increasing the total instantaneous arrays’ FoV. From an enlarged field of view also benefits the search for very-high-energy transient sources, making it possible to cover large sky regions in follow-up observations, or to quickly cover the probability sky map in case of Gamma Ray Bursts (GRB), Gravitational Waves (GW), and other transient events. In this contribution, we present the proposed implementation of the divergent pointing mode and its first preliminary performance estimation for the southern CTAO array.
Ključne besede: Cherenkov Telescope Array, CTAO, divergent mode, very-high-energy transient sources
Objavljeno v RUNG: 26.09.2023; Ogledov: 544; Prenosov: 5
.pdf Celotno besedilo (554,96 KB)
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