1. Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger ObservatoryRoberta Colalillo, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2023, objavljeni znanstveni prispevek na konferenci Opis: The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gammarays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very
different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle. Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays, surface detectors, extensive air shower, terrestrial gamma-ray flashes Objavljeno v RUNG: 23.01.2024; Ogledov: 1491; Prenosov: 7 Celotno besedilo (1,04 MB) Gradivo ima več datotek! Več... |
2. Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger ObservatoryOlena Tkachenko, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2023, objavljeni znanstveni prispevek na konferenci Opis: In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (�max) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with �max distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energydependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations
of the proton-proton cross-sections from low-energy accelerator data. Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays, extensive air shower, hadronic interactions, cross-section, Xmax Objavljeno v RUNG: 23.01.2024; Ogledov: 2140; Prenosov: 6 Celotno besedilo (917,40 KB) Gradivo ima več datotek! Več... |
3. 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: 1782; Prenosov: 7 Celotno besedilo (827,67 KB) Gradivo ima več datotek! Več... |
4. 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, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays (UHECR), extensive air showers, Auger Surface Detector (SD) array, depth
of shower maximum Objavljeno v RUNG: 21.12.2020; Ogledov: 3066; Prenosov: 69 Celotno besedilo (850,78 KB) |
5. The muon component of extensive air showers above 10[sup]17.5 eV measured with the Pierre Auger ObservatoryFederico Sánchez, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: ultra-high energy cosmic rays, Pierre Auger Observatory, extensive air showers, muon shower component Objavljeno v RUNG: 29.11.2020; Ogledov: 3487; Prenosov: 0 Gradivo ima več datotek! Več... |
6. CORSIKA Simulation of the Telescope Array Surface DetectorT. Abu-Zayyad, Jon Paul Lundquist, 2014, izvirni znanstveni članek Opis: The Telescope Array is the largest experiment studying ultra-high energy cosmic rays in the northern hemisphere. The detection area of the experiment consists of an array of 507 surface detectors, and a fluorescence detector divided into three sites at the periphery. The viewing directions of the 38 fluorescence telescopes point over the air space above the surface array. In this paper, we describe a technique that we have developed for simulating the response of the array of surface detectors of the Telescope Array experiment. The two primary components of this method are (a) the generation of a detailed CORSIKA Monte Carlo simulation with all known characteristics of the data, and (b) the validation of the simulation by a direct comparison with the Telescope Array surface detector data. This technique allows us to make a very accurate calculation of the acceptance of the array. We also describe a study of systematic uncertainties in this acceptance calculation. Ključne besede: cosmic ray, extensive air shower, simulation, surface detector Objavljeno v RUNG: 19.05.2020; Ogledov: 3307; Prenosov: 0 Gradivo ima več datotek! Več... |
7. The surface detector array of the Telescope Array experimentT. Abu-Zayyad, Jon Paul Lundquist, 2012, izvirni znanstveni članek Opis: The Telescope Array (TA) experiment, located in the western desert of Utah, USA, is designed for the observation of extensive air showers from extremely high energy cosmic rays. The experiment has a surface detector array surrounded by three fluorescence detectors to enable simultaneous detection of shower particles at ground level and fluorescence photons along the shower track. The TA surface detectors and fluorescence detectors started full hybrid observation in March, 2008. In this article we describe the design and technical features of the TA surface detector. Ključne besede: Ultra-high energy cosmic rays, Telescope Array experiment, Extensive air shower array Objavljeno v RUNG: 19.05.2020; Ogledov: 3454; Prenosov: 0 Gradivo ima več datotek! Več... |
8. Study of Ultra-High Energy Cosmic Ray composition using Telescope Array’s Middle Drum detector and surface array in hybrid modeR.U. Abbasi, Jon Paul Lundquist, 2015, izvirni znanstveni članek Opis: Previous measurements of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly’s Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory, but utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in some, but not all, respects in methodology to PAO, and good agreement is evident between data and a light, largely protonic, composition when comparing the measurements to predictions obtained with the QGSJetII-03 and QGSJet-01c models. These models are also in agreement with previous HiRes stereo measurements, confirming the equivalence of the stereo and hybrid methods. The data is incompatible with a pure iron composition, for all models examined, over the available range of energies. The elongation rate and mean values of are in good agreement with Pierre Auger Observatory data. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique. Ključne besede: Ultra-High Energy Cosmic Rays, Cosmic ray composition, Atmospheric fluorescence, Extensive air shower array, Hybrid, Telescope Array Objavljeno v RUNG: 24.04.2020; Ogledov: 3842; Prenosov: 0 Gradivo ima več datotek! Več... |
9. Measurement of the energy spectrum of cosmic rays with the Pierre Auger ObservatoryVitor de Souza, Andrej Filipčič, Ahmed Saleh, Samo Stanič, Darko Veberič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2016, objavljeni znanstveni prispevek na konferenci Ključne besede: Ultra-high energy cosmic rays (UHECR), UHECR elemental composition, Pierre Auger Observatory, extensive air showers (EAS), EAS longitudinal profiles, depth of shower maximum Objavljeno v RUNG: 09.11.2016; Ogledov: 5291; Prenosov: 0 Gradivo ima več datotek! Več... |
10. Initial results of a direct comparison between the Surface Detectors of the Pierre Auger Observatory and the Telescope ArrayR. Takeishi, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The Pierre Auger Observatory (Auger) in Mendoza, Argentina and
the Telescope Array (TA) in Utah, USA aim at unraveling the
origin and nature of Ultra-High Energy Cosmic Rays (UHECR).
At present, there appear to be subtle differences between Auger
and TA results and interpretations. Joint working groups have
been established and have already reported preliminary
findings. From an experimental standpoint, the Surface
Detectors (SD) of both experiments make use of different
detection processes not equally sensitive to the components of
the extensive air showers making it to the ground. In particular, the muonic component of the shower measured at
ground level can be traced back to the primary composition,
which is critical for understanding the origin of UHECRs.
In order to make direct comparisons between the SD detection
techniques used by Auger and TA, a joint SD experimental
research program is being developed. In the first phase,
two Auger SD stations were deployed at the TA Central Laser
Facility to compare station-level responses. This paper
concentrates on the results obtained with the first Auger SD
station (an “Auger North” design), which has been operating
since October 2014. The second Auger SD station, identical to
the ones being operated at Auger in Argentina (an “Auger South”
design), was just deployed in June 2015. The second phase of
this research program will be to co-locate six Auger North SD
stations with TA stations in the field to compare event-level
responses. Ključne besede: Ultra-High Energy Cosmic Rays, Pierre Auger Observatory, Telescope Array, extensive air showers, secondary cosmic rays, muonic shower component, surface detectors Objavljeno v RUNG: 08.03.2016; Ogledov: 5579; Prenosov: 191 Celotno besedilo (1,42 MB) |