151. Measurement of the fluctuations in the number of muons in extensive air showers with the Pierre Auger ObservatoryA. Aab, Andrej Filipčič, Gašper Kukec Mezek, Jon Paul Lundquist, Samo Stanič, Marta Trini, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2021, original scientific article Keywords: ultra-high energy cosmic rays, extensive air showers (EAS), EAS muonic component, hadronic interaction models, Pierre Auger Observatory Published in RUNG: 29.04.2021; Views: 2239; Downloads: 0 This document has many files! More... |
152. Calibration of the underground muon detector of the Pierre Auger ObservatoryA. Aab, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Marta Trini, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2021, original scientific article Abstract: To obtain direct measurements of the muon content of extensive air showers with energy above 10[sup]16.5 eV, the Pierre Auger Observatory is currently being equipped with an underground muon detector (UMD), consisting of 219 10 m[sup]2-modules, each segmented into 64 scintillators coupled to silicon photomultipliers (SiPMs). Direct access to the shower muon content allows for the study of both of the composition of primary cosmic rays and of high-energy hadronic interactions in the forward direction. As the muon density can vary between tens of muons per m[sup]2 close to the intersection of the shower axis with the ground to much less than one per m[sup]2 when far away, the necessary broad dynamic range is achieved by the simultaneous implementation of two acquisition modes in the read-out electronics: the binary mode, tuned to count single muons, and the ADC mode, suited to measure a high number of them. In this work, we present the end-to-end calibration of the muon detector modules: first, the SiPMs are calibrated by means of the binary channel, and then, the ADC channel is calibrated using atmospheric muons, detected in parallel to the shower data acquisition. The laboratory and field measurements performed to develop the implementation of the full calibration chain of both binary and ADC channels are presented and discussed. The calibration procedure is reliable to work with the high amount of channels in the UMD, which will be operated continuously, in changing environmental conditions, for several years. Keywords: ultra-high energy cosmic rays, extensive air showers (EAS), EAS muonic component, Pierre Auger Observatory, underground muon detector, detector calibration Published in RUNG: 14.04.2021; Views: 2800; Downloads: 139 Link to full text This document has many files! More... |
153. Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagationH. Abdalla, H. Abe, Fabio Acero, A. Acharyya, R. Adam, Christopher Eckner, Samo Stanič, Serguei Vorobiov, Gabrijela Zaharijas, Marko Zavrtanik, Danilo Zavrtanik, Miha Živec, 2021, original scientific article Abstract: The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for γ astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of γ cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of γ absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift z=2 and to constrain or detect γ halos up to intergalactic-magnetic-field strengths of at least 0.3 pG . Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from γ astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of γ cosmology. Keywords: Cherenkov Telescope Array, active galactic nuclei, gamma-ray experiments, axions, extragalactic magnetic fields Published in RUNG: 02.03.2021; Views: 2382; Downloads: 71 Link to full text This document has many files! More... |
154. Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centreA. Acharyya, R. Adam, C. Adams, I. Agudo, A. Aguirre-Santaella, Christopher Eckner, Samo Stanič, Serguei Vorobiov, Gabrijela Zaharijas, Marko Zavrtanik, Danilo Zavrtanik, Miha Živec, 2021, original scientific article Keywords: dark matter, gamma ray, astrophysics Published in RUNG: 26.02.2021; Views: 2491; Downloads: 141 Link to full text This document has many files! More... |
155. Scrutinizing FR 0 radio galaxies as ultra-high-energy cosmic ray source candidatesLukas Merten, Margot Boughelilba, Anita Reimer, Paolo Da Vela, Serguei Vorobiov, Fabrizio Tavecchio, Giacomo Bonnoli, Jon Paul Lundquist, Chiara Righi, 2021, original scientific article Abstract: Fanaroff-Riley (FR) 0 radio galaxies compose a new class of radio galaxies, which are usually weaker but much more numerous than the well-established class of FR 1 and FR 2 galaxies. The latter classes have been proposed as sources of the ultra-high-energy cosmic rays (UHECRs) with energies reaching up to eV. Based on this conjecture, the possibility of UHECR acceleration and survival in an FR 0 source environment is examined in this work.
In doing so, an average spectral energy distribution (SED) based on data from the FR 0 catalog (FR0CAT) is compiled. The resulting photon fields are used as targets for UHECRs, which suffer from electromagnetic pair production, photo-disintegration, photo-meson production losses, and synchrotron radiation. Multiple mechanisms are discussed to assess the UHECR acceleration probability, including Fermi-I order and gradual shear accelerations, and particle escape from the source region.
This work shows that in a hybrid scenario, combining Fermi and shear accelerations, FR 0 galaxies can contribute to the observed UHECR flux, as long as where shear acceleration starts to dominate over escape. Even in less optimistic scenarios, FR 0s can be expected to contribute to the cosmic-ray flux between the knee and the ankle. Our results are relatively robust with respect to the realized magnetic turbulence model and the speed of the accelerating shocks. Keywords: acceleration of particles, nonthermal radiation mechanisms, jets, active galaxies, cosmic rays Published in RUNG: 05.02.2021; Views: 2643; Downloads: 0 This document has many files! More... |
156. Search for Correlations of High-energy Neutrinos and Ultra-high Energy Cosmic RaysA.M. Barbano, Andrej Filipčič, Gašper Kukec Mezek, Jon Paul Lundquist, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, published scientific conference contribution Keywords: ultra-high energy cosmic rays (UHECR), high-energy neutrinos, arrival directions, correlation search, IceCube neutrino
observatory, Pierre Auger Observatory, Telescope Array, ANTARES neutrino observatory Published in RUNG: 22.12.2020; Views: 2599; Downloads: 83 Full text (400,93 KB) |
157. Working Group Report on the Combined Analysis of Muon Density Measurements from Eight Air Shower ExperimentsLorenzo Cazon, Andrej Filipčič, Gašper Kukec Mezek, Jon Paul Lundquist, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, published scientific conference contribution Keywords: extensive air showers (EAS), muon density measurements in EAS, EAS-MSU array, IceCube neutrino observatory, KASCADE-Grande, NEVOD-DECOR, Pierre Auger Observatory, SUGAR, Telescope Array, Yakutsk EAS array Published in RUNG: 22.12.2020; Views: 2323; Downloads: 85 Full text (620,78 KB) |
158. Follow-up searches for ultra-high energy neutrinos from transient astrophysical sources with the Pierre Auger ObservatoryMichael Schimp, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, published scientific conference contribution Keywords: Pierre Auger Observatory, transient astrophysical sources, binary black hole mergers, gravitational wave events, blazar TXS 0506+056, follow-up search for counterpart ultra-high energy neutrinos Published in RUNG: 21.12.2020; Views: 2606; Downloads: 71 Full text (366,82 KB) |
159. Analysis of Data from Surface Detector Stations of the AugerPrime UpgradeÁlvaro Taboada, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, published scientific conference contribution Keywords: Pierre Auger Observatory (PAO), ultra-high energy cosmic rays, AugerPrime upgrade of the PAO, Scintillator Surface Detector (SSD), Water-Cherenkov Detectors (WCDs), AugerPrime data analysis Published in RUNG: 21.12.2020; Views: 2465; Downloads: 64 Full text (2,56 MB) |
160. Estimating the Depth of Shower Maximum using the Surface Detectors of the Pierre Auger ObservatoryCarlos José Todero Peixoto, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, published scientific conference contribution Keywords: Pierre Auger Observatory, ultra-high energy cosmic rays (UHECR), extensive air showers, Auger Surface Detector (SD) array, depth
of shower maximum Published in RUNG: 21.12.2020; Views: 2317; Downloads: 66 Full text (850,78 KB) |