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1.
Expected performance of the Auger Radio Detector
Felix Schlüter, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2023, objavljeni znanstveni prispevek na konferenci

Opis: The Auger Radio Detector (RD) will increase the sky coverage and overall aperture for mass- sensitive measurements of ultra-high-energy cosmic rays with the Pierre Auger Observatory. The installation of over 1600 dual-polarized short aperiodic loaded loop antennas (SALLAs) on an area of about 3000 sq. km will enable the detection of highly inclined air showers via the emitted electromagnetic radiation in coincidence with the Auger water-Cherenkov detector array (SD). The combination of complementary information from both detectors yields a strong sensitivity to the mass composition of cosmic rays. We will present the expected performance of the RD to detect and reconstruct inclined air showers. This study features comprehensive sets of Monte-Carlo generated air showers, utilizes a complete description of the instrumental response of the radio antennas, and in-situ recorded background. The estimation of an energy- and direction-dependent aperture yields an expectation of about 3900 events with energies above 10[sup]19 eV being detected during 10 years of operation. From a full event reconstruction, we quantify the achievable energy resolution to be better than 10% at and beyond 10[sup]19 eV. With this at hand, the potential to measure the number of muons and discriminate between different cosmic-ray primaries in combination with the SD using inclined air showers is presented. The discrimination between proton- and iron-induced air showers yields a figure-of-merit of 1.6.
Ključne besede: Pierre Auger Observatory, ultra-high-energy cosmic rays, extensive air showers, Auger Radio Detector, Auger water-Cherenkov detector array, mass-sensitive UHECR measurements
Objavljeno v RUNG: 03.10.2024; Ogledov: 207; Prenosov: 0
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2.
Absolute calibration and investigation of ageing of the AERA radio detectors
Rogerio 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: 205; Prenosov: 0
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3.
Measuring the muon content of inclined air showers using AERA and the particle detector of the Pierre Auger Observatory
P. 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: 181; Prenosov: 0
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Investigation of multi-messenger properties of FR0 radio galaxy emitted ultra-high energy cosmic rays
Jon Paul Lundquist, Lukas Merten, Serguei Vorobiov, Margot Boughelilba, Albert Reimer, Paolo Da Vela, F. Tavecchio, G. Bonnoli, C. Righi, 2023, objavljeni znanstveni prispevek na konferenci

Opis: Low luminosity Fanaroff-Riley type 0 (FR0) radio galaxies are amongst potential contributors to the observed flux of ultra-high energy cosmic rays (UHECRs). Due to FR0s’ much higher abundance in the local universe than more powerful radio galaxies (e.g., about five times more ubiquitous at redshifts z≤0.05 than FR1s), they could provide a substantial fraction of the total UHECR energy density. In the presented work, we determine the mass composition and energy spectrum of UHECRs emitted by FR0 sources by fitting simulation results from the CRPropa3 framework to the recently published Pierre Auger Observatory data. The resulting emission spectral characteristics (spectral indices, rigidity cutoffs) and elemental group fractions are compared to the Auger results. The FR0 simulations include the approximately isotropic distribution of FR0s extrapolated from the measured FR0 galaxy properties and various extragalactic magnetic field configurations, including random and large-scale structured fields. We predict the fluxes of secondary photons and neutrinos produced during UHECR propagation through cosmic photon backgrounds. The presented results allow for probing the properties of the FR0 radio galaxies as cosmic-ray sources using observational high-energy multi-messenger data.
Ključne besede: ultra-high energy cosmic rays, UHECRs, Pierre Auger Observatory, UHECR propagation, UHECR interactions, UHECR energy spectrum, UHECR mass composition, UHECR sources, Fanaroff-Riley (FR) radio galaxies, FR0 galaxies
Objavljeno v RUNG: 24.01.2024; Ogledov: 1299; Prenosov: 40
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7.
Radio interferometry applied to air showers recorded by the Auger engineering radio array
H. Schoorlemmer, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2023, objavljeni znanstveni prispevek na konferenci

Opis: A new radio interferometric technique was recently developed that takes into account time lags caused by the three-dimensional dependency of the refractive index in the atmosphere. It enables us to track the extensive air shower while it propagates through the atmosphere. Using this technique, properties of the air shower can be estimated, like the depth of maximum and the axis of propagation. In order to apply this method, strict constraints on the time-synchronisation between radio antennas in an array must be satisfied. In this contribution, we show that the Auger Engineering Radio Array can meet these timing criteria by operating a time reference beacon. We will show how this enables us to reconstruct air shower properties using the radio interferometric technique.
Ključne besede: ultra-high energy cosmic rays, Pierre Auger Observatory, Auger engineering radio array, radio interferometry
Objavljeno v RUNG: 23.01.2024; Ogledov: 1353; Prenosov: 5
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8.
Status and expected performance of the AugerPrime radio detector
Jannis Pawlowsky, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2023, objavljeni znanstveni prispevek na konferenci

Opis: The ongoing AugerPrime upgrade of the Pierre Auger Observatory will yield sensitivity and precision for measuring ultra-high energy (UHE) cosmic rays that are significantly improved over the baseline design. A key part is the installation of the Radio Detector (RD), consisting of loop antennas mounted on top of each of the 1660 water-Cherenkov detectors (WCD). These antennas, with polarizations both parallel and perpendicular to Earth’s magnetic field, are sensitive to inclined air showers and will also improve the sky coverage and exposure of the observatory. Of special interest is the great sensitivity to the electromagnetic component of air showers, yielding new information for the reconstruction of the primary mass, energy and arrival direction. Complementing traditional particle detectors like the WCD, the combination of both yields new opportunities to detect rare primary particles, e.g. UHE photons and neutrinos with a large identification probability. Here we present the status and future prospects of the RD.With mass production and deployment ongoing, we showair shower statistics and reconstructions of the already installed detector stations. We detail the layout and integration of the RD, demonstrating the potential of the observatory including radio measurements and RD triggering, especially to detect air showers with weak particle footprints. We show that the new trigger enables the measurement of events for which traditional particle detectors are less sensitive.
Ključne besede: ultra-high energy cosmic rays, Pierre Auger Observatory, radio detector, air shower
Objavljeno v RUNG: 23.01.2024; Ogledov: 1108; Prenosov: 6
.pdf Celotno besedilo (7,29 MB)
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9.
Long-term calibration and stability of the Auger Engineering Radio Array using the diffuse Galactic radio emission
R. M. de Almeida, Andrej Filipčič, Jonathan Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2023, objavljeni znanstveni prispevek na konferenci

Opis: The Auger Engineering Radio Array (AERA), part of the Pierre Auger Observatory, is currently the largest facility to measure radio emissions from ultra-high energy extensive air showers. It comprises 153 autonomous radio-detector stations, covering an area of 17 km^2, and measures radio waves in the frequency range from 30 to 80 MHz. An accurate description of the detector response is necessary to interpret the data collected by the stations correctly. Previously, this was achieved by measuring the analog chain in the laboratory and simulating and measuring the directional response of the antenna. In this work, we perform an absolute calibration using the continuously monitored sidereal modulation of the diffuse Galactic radio emission. The calibration is performed by comparing the average spectra recorded by the stations with a model of the full radio sky propagated through the system response, including the antenna, filters, and amplifiers. We describe the method to determine the calibration constants for each antenna and present the corresponding results. Furthermore, the behavior of the calibration constants is studied as a function of time. There is no relevant aging effect over a timescale of a decade, which shows that radio detectors could help monitor possible aging effects of other detector systems during long-term operations, stressing their importance in determining an absolute energy scale.
Ključne besede: pierre auger observatory, auger engineering radio array, ultra-high energy cosmic rays, radio detectors
Objavljeno v RUNG: 22.01.2024; Ogledov: 1414; Prenosov: 35
.pdf Celotno besedilo (1,03 MB)
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10.
Hevreka (Supernove tipa 1a)
Tanja Petrushevska, Japelj Jure, radijska ali televizijska oddaja, podkast, intervju, novinarska konferenca

Opis: V vesolju tudi poka kot za stavo. Zvezde, ki večino življenja ne počnejo nič drugega kot spreminjajo vodik v helij, si včasih zaželijo pozornosti in eksplodirajo kot supernove. Zvezda kar naenkrat postana svetlejša od celotne galaksije, zato supernove vidimo tudi, ko eksplodirajo daleč, daleč stran. Astronomi vesoljski ognjemet seveda z veseljem opazujejo. Supernove namreč niso zgolj izjemno svetle, ampak igrajo pomembno vlogo pri številnih procesih v vesolju. Kozmične eksplozije so različnih tipov in okusov, verjetno najbolj slavne med njimi pa so supernove tipa 1a. Te nam je približala doktorica Tanja Petrushevska, docentka na Fakulteti za naravoslovje Univerze v Novi Gorici. Pred mikrofon jo je povabil dr. Jure Japelj.
Ključne besede: radio, intervju, supernova
Objavljeno v RUNG: 24.11.2023; Ogledov: 1128; Prenosov: 4
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