91. The fitting procedure for longitudinal shower profiles observed with the fluorescence detector of the Pierre Auger ObservatoryJ. A. Bellido, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2023, objavljeni znanstveni prispevek na konferenci Opis: The Pierre Auger Observatory uses fluorescence telescopes in conjunction with ground level
particle detectors to measure high-energy cosmic rays and reconstruct, with greater precision,
their arrival direction, their energy and the depth of shower maximum. The depth of shower
maximum is important to infer cosmic ray mass composition. The fluorescence detector is
capable of directly measuring the longitudinal shower development, which is used to reconstruct
the cosmic ray energy and the atmospheric depth of shower maximum. However, given the limited
field of view of the fluorescence detector, the shower profile is not always fully contained within
the detector observation volume. Therefore, considerations need to be taken in order to reconstruct
some events. In this contribution we will describe the method that the Pierre Auger Collaboration
uses to reconstruct the longitudinal profiles of showers and present the details of its performance,
namely its resolution and systematic uncertainties.
Ključne besede: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, longitudinal shower profiles
Objavljeno v RUNG: 20.09.2023; Ogledov: 1731; Prenosov: 7
 Celotno besedilo (827,67 KB)
Gradivo ima več datotek! Več... |
92. GCOS - The Global Cosmic Ray ObservatoryJoerg R. Hoerandel, Serguei Vorobiov, Danilo Zavrtanik, 2021, objavljeni znanstveni prispevek na konferenci (vabljeno predavanje) Opis: Nature is providing particles with energies exceeding 100 EeV. Their existence imposes immediate questions: Are they ordinary particles, accelerated in extreme astrophysical environments, or are they annihilation or decay products of super-heavy dark matter or other exotic objects? If the particles are accelerated in extreme astrophysical environments, are their sources related to those of high-energy neutrinos, gamma rays, and/or gravitational waves, such as the recently observed mergers of compact objects? The particles can also be used to study physics processes at extreme energies; is Lorentz invariance still valid? Are the particles interacting according to the Standard
Model or are there new physics processes? The particles can be used to study hadronic interactions (QCD) in the kinematic forward direction; what is the cross section of protons at center-of-mass energies sqrt(s) > 100 TeV?
These questions are addressed at present by installations like the Telescope Array and the Pierre Auger Observatory. After the year 2030, a next-generation observatory will be needed to study the physics and properties of the highest-energy particles in Nature, building on the knowledge harvested from the existing observatories. It should have an aperture at least an order of magnitude bigger than the existing observatories.
Recently, more than 200 scientists from around the world came together to discuss the future of the
field of multi-messenger astroparticle physics beyond the year 2030. Ideas have been discussed
towards the physics case and possible scenarios for detection concepts of the Global Cosmic Ray
Observatory - GCOS. A synopsis of the key results discussed during the brainstorming workshop
will be presented.
Ključne besede: ultra-high-energy cosmic rays, Pierre Auger Observatory, Telescope Array, Global Cosmic Ray
Observatory (GCOS) project
Objavljeno v RUNG: 13.09.2023; Ogledov: 1458; Prenosov: 7
Celotno besedilo (5,89 MB)
Gradivo ima več datotek! Več... |
93. The UHECR-FR0 radio galaxy connection : a multi-messenger study of energy spectra/composition emission and intergalactic magnetic field propagationJon Paul Lundquist, Lukas Merten, Serguei Vorobiov, Margot Boughelilba, Anita Reimer, Paolo Da Vela, Fabrizio Tavecchio, Giacomo Bonnoli, Chiara Righi, 2023, objavljeni znanstveni prispevek na konferenci Opis: This study investigates low luminosity Fanaroff-Riley Type 0 (FR0) radio galaxies as a potentially
significant source of ultra-high energy cosmic rays (UHECRs). Due to their much higher prevalence
in the local universe compared to more powerful radio galaxies (about five times more than
FR-1s), FR0s may provide a substantial fraction of the total UHECR energy density. To determine
the nucleon composition and energy spectrum of UHECRs emitted by FR0 sources, simulation
results from CRPropa3 are fit to Pierre Auger Observatory data. The resulting emission spectral
indices, rigidity cutoffs, and nucleon fractions are compared to recent Auger results. The FR0 simulations
include the approximately isotropic distribution of FR0 galaxies and various intergalactic
magnetic field configurations (including random and structured fields) and predict the fluxes of
secondary photons and neutrinos produced during UHECR propagation through cosmic photon
backgrounds. This comprehensive simulation allows for investigating the properties of the FR0
sources using observational multi-messenger data.
Ključne besede: ultra-high energy cosmic rays, UHECR propagation, CRPropa, active galactic nuclei, jetted AGN, FR0 radio galaxies, Pierre Auger Observatory, UHECR energy spectrum
Objavljeno v RUNG: 24.08.2023; Ogledov: 1785; Prenosov: 5
Celotno besedilo (1,12 MB)
Gradivo ima več datotek! Več... |
94. Constraining the sources of ultra-high-energy cosmic rays across and above the ankle with the spectrum and composition data measured at 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: In this work we present the interpretation of the energy spectrum and mass composition data as measured by the Pierre Auger Collaboration above 6 × 10[sup]17 eV. We use an astrophysical model with two extragalactic source populations to model the hardening of the cosmic-ray flux at around 5 × 10[sup]18 eV (the so-called "ankle" feature) as a transition between these two components. We find our data to be well reproduced if sources above the ankle emit a mixed composition with a hard spectrum and a low rigidity cutoff. The component below the ankle is required to have a very soft spectrum and a mix of protons and intermediate-mass nuclei. The origin of this intermediate-mass component is not well constrained and it could originate from either Galactic or extragalactic sources. To the aim of evaluating our capability to constrain astrophysical models, we discuss the impact on the fit results of the main experimental systematic uncertainties and of the assumptions about quantities affecting the air shower development as well as the propagation and redshift distribution of injected ultra-high-energy cosmic rays (UHECRs).
Ključne besede: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, UHECR propagation, UHECR energy spectrum, UHECR mass composition
Objavljeno v RUNG: 18.08.2023; Ogledov: 1598; Prenosov: 11
Celotno besedilo (2,39 MB)
Gradivo ima več datotek! Več... |
95. 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: 1613; Prenosov: 14
Celotno besedilo (2,46 MB)
Gradivo ima več datotek! Več... |
96. |
97. 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: 1946; Prenosov: 0
Gradivo ima več datotek! Več... |
98. 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: 1997; Prenosov: 0
Gradivo ima več datotek! Več... |
99. 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: 2054; Prenosov: 19
Celotno besedilo (8,87 MB)
Gradivo ima več datotek! Več... |
100. 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: 2373; Prenosov: 0
Gradivo ima več datotek! Več... |
