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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, published scientific conference contribution

Abstract: 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.
Keywords: 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
Published in RUNG: 24.01.2024; Views: 677; Downloads: 39
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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, published scientific conference contribution

Abstract: 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.
Keywords: ultra-high energy cosmic rays, Pierre Auger Observatory, Auger engineering radio array, radio interferometry
Published in RUNG: 23.01.2024; Views: 687; Downloads: 4
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5.
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, published scientific conference contribution

Abstract: 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.
Keywords: ultra-high energy cosmic rays, Pierre Auger Observatory, radio detector, air shower
Published in RUNG: 23.01.2024; Views: 571; Downloads: 5
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6.
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, published scientific conference contribution

Abstract: 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.
Keywords: pierre auger observatory, auger engineering radio array, ultra-high energy cosmic rays, radio detectors
Published in RUNG: 22.01.2024; Views: 653; Downloads: 34
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Hevreka (Supernove tipa 1a)
Tanja Petrushevska, Japelj Jure, radio or television broadcast, podcast, interview, press conference

Abstract: 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.
Keywords: radio, intervju, supernova
Published in RUNG: 24.11.2023; Views: 680; Downloads: 2
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8.
Monte Carlo simulations for the Pierre Auger Observatory using the VO auger grid resources
E. Santos, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, published scientific conference contribution

Abstract: The Pierre Auger Observatory, located near Malargüe, Argentina, is the world’s largest cosmic-ray detector. It comprises a 3000 km^2 surface detector and 27 fluorescence telescopes, which measure the lateral and longitudinal distributions of the many millions of air-shower particles produced in the interactions initiated by a cosmic ray in the Earth’s atmosphere. The determination of the nature of cosmic rays and studies of the detector performances rely on extensive Monte Carlo simulations describing the physics processes occurring in extensive air showers and the detector responses. The aim of the Monte Carlo simulations task is to produce and provide the Auger Collaboration with reference libraries used in a wide variety of analyses. All multipurpose detector simulations are currently produced in local clusters using Slurm and HTCondor. The bulk of the shower simulations are produced on the grid, via the Virtual Organization auger, using the DIRAC middleware. The job submission is made via python scripts using the DIRAC-API. The Auger site is undergoing a major upgrade, which includes the installation of new types of detectors, demanding increased simulation resources. The novel detection of the radio component of extensive air showers is the most challenging endeavor, requiring dedicated shower simulations with very long computation times, not optimized for the grid production. For data redundancy, the simulations are stored on the Lyon server and the grid Disk Pool Manager and are accessible to the Auger members via iRODS and DIRAC, respectively. The CERN VMFile System is used for software distribution where, soon, the Auger Offline software will also be made available.
Keywords: Pierre Auger Observatory, indirect detection, fluorescence detection, surface detection, radio detection, ultra-high energy, cosmic rays, Monte Carlo simulation, computing resources, compute clusters, high capacity storage
Published in RUNG: 04.10.2023; Views: 844; Downloads: 7
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9.
Expected performance of the AugerPrime Radio Detector
F. Schlüter, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, published scientific conference contribution

Abstract: The AugerPrime Radio Detector will significantly increase the sky coverage of mass-sensitive measurements of ultra-high energy cosmic rays with the Pierre Auger Observatory. The detection of highly inclined air showers with the world’s largest 3000km^2 radio-antenna array in coincidence with the Auger water-Cherenkov detector provides a clean separation of the electromagnetic and muonic shower components. The combination of these highly complementary measurements yields a strong sensitivity to the mass composition of cosmic rays. We will present the first results of an end-to-end simulation study of the performance of the AugerPrime Radio Detector. The study features a complete description of the AugerPrime radio antennas and reconstruction of the properties of inclined air showers, in particular the electromagnetic energy. The performance is evaluated utilizing a comprehensive set of simulated air showers together with recorded background. The estimation of an energy- and direction-dependent aperture yields an estimation of the expected 10-year event statistics. The potential to measure the number of muons in air showers with the achieved statistics is outlined. Based on the achieved energy resolution, the potential to discriminate between different cosmic-ray primaries is presented.
Keywords: Pierre Auger Observatory, AugerPrime, indirect detection, radio detection, radio antenna array, ultra-high energy, cosmic rays, air-shower muons, composition
Published in RUNG: 04.10.2023; Views: 835; Downloads: 6
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10.
First results from the AugerPrime Radio Detector
T. Fodran, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, published scientific conference contribution

Abstract: The Pierre Auger Observatory investigates the properties of the highest-energy cosmic rays with unprecedented precision. The aim of the AugerPrime upgrade is to improve the sensitivity to the primary particle type. The improved mass sensitivity is the key to exploring the origin of the highest-energy particles in the Universe. The purpose of the Radio Detector (as part of AugerPrime) is to extend the sensitivity of the mass measurements to zenith angles in the range from 65° to 85°. A radio antenna, sensitive in two polarization directions and covering a bandwidth from 30 to 80 MHz, will be added to each of the 1661 surface detector stations over the full 3000 km^2 area, forming the world’s largest radio array for the detection of cosmic particles. Since November 2019, an engineering array comprised of ten stations has been installed in the field. The radio antennas are calibrated using the Galactic (diffuse) emission. The sidereal modulation of this signal is monitored continuously and is used to obtain an end-to-end calibration from the receiving antenna to the ADC in the read-out electronics. The calibration method and first results will be presented. The engineering array is also fully integrated in the data acquisition of the Observatory and records air showers regularly. The first air showers detected simultaneously with the water-Cherenkov detectors and the Radio Detectors will be presented. Simulations of the detected showers, based on the reconstructed quantities, have been conducted with CORSIKA/CoREAS. A comparison of the measured radio signals with those predicted by simulations exhibits satisfying agreement.
Keywords: Pierre Auger Observatory, AugerPrime, indirect detection, radio detection, radio antenna array, surface detection, ground array, ultra-high energy, cosmic rays, galactic radio emission
Published in RUNG: 04.10.2023; Views: 785; Downloads: 6
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