91. Absolute calibration and investigation of ageing of the AERA radio detectorsRogerio M. De Almeida, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2023, objavljeni znanstveni prispevek na konferenci Opis: The Auger Engineering Radio Array (AERA) is currently the largest facility to measure radio emissions from extensive air showers. Located at the Pierre Auger Observatory in Argentina,
it comprises 153 autonomous radio-detector stations, covering an area of 17 sq. km, and measures radio waves in the frequency range from 30 to 80 MHz. For the correct interpretation of data collected by AERA stations, the detector response has to be carefully calibrated. In the past, this was done by measuring the analogue chain in the laboratory, in addition to simulating and measuring the directional response of the antenna. In this work, we perform an absolute calibration by using the radio emission from the Galaxy. A model of the full radio sky is propagated through the system response, including the antenna, filters and amplifiers, and compared to the average spectra recorded by the stations. The method to determine the calibration constants, as the results, for each antenna will be presented. The behavior of the calibration constants is studied as a function of time from 2014 to 2020. There is no relevant ageing effect over a timescale of 10 years, showing that radio detectors could help to monitor possible ageing effects of other detector systems during long-term operations, stressing their importance in determining an absolute energy scale.
Ključne besede: Pierre Auger Observatory, ultra-high-energy cosmic rays, extensive air showers, engineering radio array
Objavljeno v RUNG: 03.10.2024; Ogledov: 423; Prenosov: 1
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92. Measuring the muon content of inclined air showers using AERA and the particle detector of the Pierre Auger ObservatoryP. Abreu, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2023, objavljeni znanstveni prispevek na konferenci Opis: A first measurement of the muon content of air showers using hybrid measurements combining radio and particle detection is presented. For inclined air showers with zenith angles above 60°,
the water-Cherenkov detector (WCD) of the Pierre Auger Observatory performs an almost pure measurement of the muonic component, whereas the Auger Engineering Radio Array (AERA) allows reconstructing the electromagnetic energy independently using the radio emission of
the air shower.
The analysis of more than six years of AERA data shows a deficit of muons predicted by all current-generation hadronic interaction models for energies between 4 EeV and 20 EeV. This deficit, already observed in previous analyses of Auger, is now confirmed for the first time with radio data. This analysis is limited by low statistics of only 59 high-quality events due to the small area of AERA of 17 km² and the high energy threshold of 4 EeV originating from the WCD reconstruction.
With the AugerPrime Radio Detector currently being deployed, this analysis can be extended to the highest energies to allow for in-depth tests of hadronic interaction models with large statistics.
Ključne besede: Pierre Auger Observatory, ultra-high-energy cosmic rays, extensive air showers, engineering radio array
Objavljeno v RUNG: 03.10.2024; Ogledov: 421; Prenosov: 1
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94. Chemical interactions at the interface of Au on ▫$Bi_2 Se_3$▫ topological insulatorMatjaž Valant, Sandra Gardonio, Saul Estandia, Mattia Fanetti, Andrey Vladimirovich Matetskiy, Polina M. Sheverdyaeva, Paolo Moras, Vasiliki Tileli, 2024, izvirni znanstveni članek Objavljeno v RUNG: 01.10.2024; Ogledov: 436; Prenosov: 4
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95. Genre rules as the framework for preservation and study of new media literature : predavanje na Festivalu novomedijske kulture Speculum Artium, lecture series New technologies, new perspectivesAleš Vaupotič, 2024, vabljeno predavanje na konferenci brez natisa Opis: At its core, human epistemology is based on two pillars: sense experience (consider the Humean empiricism, or phenomenology) and set-theory based logic. Quine in “Epistemology Naturalized” understands a human as a natural transformer of a meager input from senses into a torrential output of descriptions. For him also Carnap’s rational reconstruction (a logical reconstruction of the world from sense data) can be construed as creative and imaginative mechanical simulations, of the transformations from the world of experiential implications into various languages. Such a detached and rule-governed idea of games as playful alternative worlds, possibly in a reduced state as argued by Huizinga, can provide an important perspective on algorithms of new media literature, as well as its other features. Rules for particular works are summarized in genre-constructs, which will be considered for the domain where new media and literature intersect. The genres can be derived form literary traditions, and from the basic aspects of new media art that encompass the algorithmic building of communication artifacts from (more or less vast) archives of utterances in various media, and of other data. Espen Aarseth’s theory considered cybertext a perspective for the study of literature, and not a particular genre (Cybertext, 5). Finally, there is an important problem that needs to be addressed: today, several generations of work by digital media artists are firmly in the past, while media art remains synonymous with “new” and “emergent,” and the growing vastness of the loss consequently goes unacknowledged. The genre-rules based approach attempts to tackle the preservation issue by identifying the key elements of individual works that need to be recorded and preserved. The descriptions are already interpretations with an intrinsic goal of making the works re-enactable and accessible to the audiences of the future. The pilot project of preserving the Nation – Culture project by Vuk Ćosić (2000) will be outlined in the conclusion. (ARIS J7-3158, Sustainable Digital Preservation of the Slovenian New Media Art) / Aleš Vaupotič is a literary comparatist, media theorist, and new-media artist. He works at the Research Centre for Humanities at the University of Nova Gorica. Between 2021 and 2023 he was the director of the Museum of Modern Art in Ljubljana, and in 2022 the commissioner for the Slovenian Pavilion at the Venice Biennial. He is currently the project leader in an interdisciplinary research project Sustainable Digital Preservation of the Slovenian New Media Art. Among his research foci are the theory of discourse, semiotics, comparative art studies, new-media theory, methodology of digital humanities and realism in the arts. His monograph Vprašanje realizma (The Question of Realism, 2019) explores the continuities and shifts between traditional and new media.
Ključne besede: genres, new media art, cultural heritage preservation
Objavljeno v RUNG: 30.09.2024; Ogledov: 445; Prenosov: 2
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97. Search for photons above ▫$10^{18}$▫ eV by simultaneously measuring the atmospheric depth and the muon content of air showers at the Pierre Auger ObservatoryA. Abdul Halim, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2024, izvirni znanstveni članek Opis: The Pierre Auger Observatory is the most sensitive instrument to detect photons with energies above 10[sup]17 eV. It measures extensive air showers generated by ultrahigh energy cosmic rays using a hybrid technique that exploits the combination of a fluorescence detector with a ground array of particle detectors. The signatures of a photon-induced air shower are a larger atmospheric depth of the shower maximum (�max) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced cascades. In this work, a new analysis technique in the energy interval between 1 and 30 EeV (1 EeV=10[sup]18 eV) has been developed by combining the fluorescence detector-based measurement of �max with the specific features of the surface detector signal through a parameter related to the air shower muon content, derived from the universality of the air shower development. No evidence of a statistically significant signal due to photon primaries was found using data collected in about 12 years of operation. Thus, upper bounds to the integral photon flux have been set using a detailed calculation of the detector exposure, in combination with a data-driven background estimation. The derived 95% confidence level upper limits are 0.0403, 0.01113, 0.0035, 0.0023, and 0.0021 km[sup]−2 sr[sup]−1 yr[sup]−1 above 1, 2, 3, 5, and 10 EeV, respectively, leading to the most stringent upper limits on the photon flux in the EeV range. Compared with past results, the upper limits were improved by about 40% for the lowest energy threshold and by a factor 3 above 3 EeV, where no candidates were found and the expected background is negligible. The presented limits can be used to probe the assumptions on chemical composition of ultrahigh energy cosmic rays and allow for the constraint of the mass and lifetime phase space of super-heavy dark matter particles.
Ključne besede: ultra-high-energy photons, ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers
Objavljeno v RUNG: 30.09.2024; Ogledov: 544; Prenosov: 2
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