121. Search for photons above ▫$10^19$▫ eV with the surface detector of the Pierre Auger ObservatoryP. Abreu, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2023, izvirni znanstveni članek Opis: We use the surface detector of the Pierre Auger Observatory to search for air showers initiated by photons with an energy above 10[sup]19 eV. Photons in the zenith angle range from 30 deg. to 60 deg. can be identified in the overwhelming background of showers initiated by charged cosmic rays through the broader time structure of the signals induced in the water-Cherenkov detectors of the array and the steeper lateral distribution of shower particles reaching ground. Applying the search method to data collected between January 2004 and June 2020, upper limits at 95% CL are set to an E[sup]-2 diffuse flux of ultra-high energy photons above 10[sup]19 eV, 2 × 10[sup]19 eV and 4 × 10[sup]19 eV amounting to 2.11 × 10[sup]-3, 3.12 × 10[sup]-4 and 1.72 × 10[sup]-4 km-2 sr-1 yr-1, respectively. While the sensitivity of the present search around 2 × 10[sup]19 eV approaches expectations of cosmogenic photon fluxes in the case of a pure-proton composition, it is one order of magnitude above those from more realistic mixed-composition models. The inferred limits have also implications for the search of super-heavy dark matter that are discussed and illustrated. Ključne besede: ultra-high-energy cosmic rays, UHE photons, Pierre Auger Observatory, extensive air showers, water Cherenkov detectors Objavljeno v RUNG: 18.08.2023; Ogledov: 716; Prenosov: 8 Celotno besedilo (2,46 MB) Gradivo ima več datotek! Več... |
122. Search for ultra-high-energy photons from gravitational wave sources with the Pierre Auger ObservatoryA. Abdul Halim, P. Abreu, M. Aglietta, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2023, izvirni znanstveni članek Ključne besede: visokoenergijski fotoni, gravitacijski valovi, observatorij P. Auger Objavljeno v RUNG: 21.07.2023; Ogledov: 762; Prenosov: 4 Celotno besedilo (636,37 KB) Gradivo ima več datotek! Več... |
123. Sensitivity of the Cherenkov Telescope Array to TeV photon emission from the Large Magellanic CloudA. Acharyya, R. Adam, Saptashwa Bhattacharyya, Samo Stanič, Veronika Vodeb, Serguei Vorobiov, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Miha Živec, 2023, izvirni znanstveni članek Opis: A deep survey of the Large Magellanic Cloud at ∼ 0.1−100 TeV photon energies with the Cherenkov Telescope Array is planned.
We assess the detection prospects based on a model for the emission of the galaxy, comprising the four known TeV emitters,
mock populations of sources, and interstellar emission on galactic scales. We also assess the detectability of 30 Doradus and SN 1987A, and the constraints that can be derived on the nature of dark matter. The survey will allow for fine spectral studies of N 157B, N 132D, LMC P3, and 30 Doradus C, and half a dozen other sources should be revealed, mainly pulsar-powered
objects. The remnant from SN 1987A could be detected if it produces cosmic-ray nuclei with a flat power-law spectrum at high energies, or with a steeper index 2.3−2.4 pending a flux increase by a factor > 3−4 over ∼ 2015−2035. Large-scale interstellar emission remains mostly out of reach of the survey if its > 10 GeV spectrum has a soft photon index ∼ 2.7, but degree-scale 0.1 − 10 TeV pion-decay emission could be detected if the cosmic-ray spectrum hardens above >100 GeV. The 30 Doradus star-forming region is detectable if acceleration efficiency is on the order of 1 − 10% of the mechanical luminosity and diffusion is suppressed by two orders of magnitude within < 100 pc. Finally, the survey could probe the canonical velocity-averaged cross section for self-annihilation of weakly interacting massive particles for cuspy Navarro-Frenk-White profiles. Ključne besede: very-high energy (VHE) gamma-rays, Cherenkov Telescope Array Observatory, Large Magellanic Cloud, pulsar wind nebulas, galaxiesstar-forming regions, cosmic rays, dark matter Objavljeno v RUNG: 02.06.2023; Ogledov: 1076; Prenosov: 1 Celotno besedilo (3,66 MB) |
124. Sensitivity of the Cherenkov Telescope Array to spectral signatures of hadronic PeVatrons with application to Galactic Supernova RemnantsFabio Acero, Saptashwa Bhattacharyya, Samo Stanič, Veronika Vodeb, Serguei Vorobiov, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Miha Živec, 2023, izvirni znanstveni članek Ključne besede: gamma-rays, cosmic rays, Galactic PeVatrons, Galactic supernova remnants, Cherenkov Telescope Array Objavljeno v RUNG: 14.04.2023; Ogledov: 1122; Prenosov: 0 Gradivo ima več datotek! Več... |
125. Limits to gauge coupling in the dark sector set by the nonobservation of instanton-induced decay of super-heavy dark matter in the Pierre Auger Observatory dataP. Abreu, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2023, izvirni znanstveni članek Ključne besede: ultra-high energy cosmic rays, UHE photon flux upper limits, super-heavy dark matter models, instantons, Pierre Auger Observatory Objavljeno v RUNG: 09.02.2023; Ogledov: 1074; Prenosov: 0 Gradivo ima več datotek! Več... |
126. Cosmological implications of photon-flux upper limits at ultrahigh energies in scenarios of Planckian-interacting massive particles for dark matterP. Abreu, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2023, izvirni znanstveni članek Ključne besede: ultra-high energy, cosmic rays, Pierre Auger Observatory, UHE photon flux upper limits, super-heavy dark matter models Objavljeno v RUNG: 09.02.2023; Ogledov: 1158; Prenosov: 0 Gradivo ima več datotek! Več... |
127. A catalog of the highest-energy cosmic rays recorded during Phase I of operation of the Pierre Auger ObservatoryA. Abdul Halim, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2023, izvirni znanstveni članek Opis: A catalog containing details of the highest-energy cosmic rays recorded through the detection of extensive air
showers at the Pierre Auger Observatory is presented with the aim of opening the data to detailed examination.
Descriptions of the 100 showers created by the highest-energy particles recorded between 2004 January 1 and 2020
December 31 are given for cosmic rays that have energies in the range 78–166 EeV. Details are also given on a
further nine very energetic events that have been used in the calibration procedure adopted to determine the energy
of each primary. A sky plot of the arrival directions of the most energetic particles is shown. No interpretations of
the data are offered. Ključne besede: ultra-high-energy cosmic rays, cosmic ray air showers, experimental data, catalogs, Pierre Auger Observatory Objavljeno v RUNG: 09.02.2023; Ogledov: 1217; Prenosov: 16 Celotno besedilo (8,87 MB) Gradivo ima več datotek! Več... |
128. Searches for Ultra-High-Energy Photons at the Pierre Auger ObservatoryP. Abreu, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, pregledni znanstveni članek Opis: The Pierre Auger Observatory, being the largest air-shower experiment in the world, offers an unprecedented exposure to neutral particles at the highest energies. Since the start of data taking more than 18 years ago, various searches for ultra-high-energy (UHE, E > 10[sup]17 eV) photons have been performed: either for a diffuse flux of UHE photons, for point sources of UHE photons or for UHE photons associated with
transient events like gravitational wave events. In the present paper, we summarize these searches and review
the current results obtained using the wealth of data collected by the Pierre Auger Observatory. Ključne besede: photons, ultra-high energies, air showers, Pierre Auger Observatory, upper limits, transients Objavljeno v RUNG: 03.01.2023; Ogledov: 1313; Prenosov: 0 Gradivo ima več datotek! Več... |
129. Arrival directions of cosmic rays above 32 EeV from phase one of the Pierre Auger ObservatoryP. Abreu, M. Aglietta, J. M. Albury, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Darko Veberič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, izvirni znanstveni članek Ključne besede: Kozmični žarki, ekstremne energije, vpadne smeri, Observatorij Pierre Auger Objavljeno v RUNG: 21.09.2022; Ogledov: 1223; Prenosov: 31 Povezava na celotno besedilo Gradivo ima več datotek! Več... |
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