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Related papers: UHECR Composition Measurements Using the HiRes-II …

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We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost four thousand events above 10^18 eV observed by the fluorescence detector of the Pierre Auger…

High Energy Astrophysical Phenomena · Physics 2012-08-27 The Pierre Auger Collaboration

Ultra-high-energy cosmic rays (UHECRs) are the most energetic particles known - and yet their origin is still an open question. However, with the precision and accumulated statistics of the Pierre Auger Observatory and the Telescope Array,…

High Energy Astrophysical Phenomena · Physics 2025-11-10 Teresa Bister

The identification of potential sources of ultra-high-energy cosmic rays (UHECRs) remains challenging due to magnetic deflections and propagation losses, which are particularly strong for nuclei. In previous iterations of this work, we…

High Energy Astrophysical Phenomena · Physics 2025-09-19 Keito Watanabe , Anatoli Fedynitch , Francesca Capel , Hiroyuki Sagawa

Digital radio arrays have become an effective tool to measure air showers at energies around and above 100 PeV. Compared to optical techniques, the radio technique is not restricted to clear nights. Thanks to recent progress on…

High Energy Astrophysical Phenomena · Physics 2022-04-28 Frank G. Schröder

The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for a next-generation UHECR observatory, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of…

We present in this paper mid-infrared (5-8~$\mu$m) spectroscopy toward the massive young binary W3~IRS~5, using the EXES spectrometer in high-resolution mode ($R\sim$50,000) from the NASA Stratospheric Observatory for Infrared Astronomy…

In this paper we introduce a new multiparametric technique that attempts to tackle simultaneously the problems of composition determination and hadronic interaction uncertainty. Employing simulations of a real world detector under its…

Astrophysics · Physics 2009-11-13 A. D. Supanitsky , G. Medina-Tanco , A. Etchegoyen

We present a novel catalog-independent method, based on a scale dependent approach, to detect anisotropy signatures in the arrival direction distribution of the ultra highest energy cosmic rays (UHECR). The method provides a good…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 M. De Domenico , H. Lyberis , A. Insolia , M. Scuderi

The Pierre Auger and Telescope Array joint Working Group on the UHECR energy spectrum was established in 2012 to analyze energy scale uncertainties in both experiments and to in vestigate their systematic differences, particularly in the…

We present a technique to measure chemical composition and particle cross-section of ultra-high energy cosmic rays using radio data. We relate the geometry of the radio footprint on the ground to the depth of the extensive air shower…

High Energy Astrophysical Phenomena · Physics 2013-12-03 Konstantin Belov

The brightest southern quasar above redshift $z=1$, HE 0515$-$4414, with its strong intervening metal absorption-line system at $z_{abs}=1.1508$, provides a unique opportunity to precisely measure or limit relative variations in the…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-07 Srđan M. Kotuš , Michael T. Murphy , Robert F. Carswell

The influence of ultra-high energy cosmic rays (UHECRs) and decaying dark matter particles on the emission and absorption characteristics of neutral hydrogen in 21 cm at redshifts $z = 10-50$ is considered. In presence of UHECRs 21 cm can…

Astrophysics · Physics 2008-11-26 Yu. A. Shchekinov , E. O. Vasiliev

We report on the first results obtained with the IceTop air shower array on the cosmic ray energy spectrum and mass composition in the range of 1 PeV to 80 PeV. IceTop is the surface detector of the IceCube neutrino telescope currently…

Astrophysics · Physics 2019-08-13 Hermann Kolanoski

As potential progenitors of several exotic phenomena including gravitational wave sources, magnetic stars, and Be stars, close massive binary systems probe a crucial area of the parameter space in massive star evolution. Despite the…

We investigate the propagation of ultraheavy (UH) nuclei as ultrahigh-energy cosmic rays (UHECRs). We show that their energy loss lengths at $\lesssim300$ EeV are significantly longer than those of protons and intermediate-mass nuclei, and…

High Energy Astrophysical Phenomena · Physics 2026-05-13 B. Theodore Zhang , Kohta Murase , Nick Ekanger , Mukul Bhattacharya , Shunsaku Horiuchi

We suggest a new approach to study the cosmis ray (CR) mass composition in the energy region from 30 TeV/nucleus up to the "knee" region, i.e. up to a few PeV/nucleus, using an array of imaging atmospheric Cherenkov telescopes (IACTs) of a…

Astrophysics · Physics 2009-11-07 F. A. Aharonian , V. V. Bugayov , J. Kettler , A. V. Plyasheshnikov , H. J. Voelk

Measurements of the products of UHECR interactions with the Earth's atmosphere, as obtained in Extended Air Shower experiments, offer important information concerning hadronic interactions, which for some aspects overlaps and for many…

High Energy Physics - Phenomenology · Physics 2025-01-03 Maria Vittoria Garzelli

Taking advantage of recent technical progress which has overcome some of the difficulties encountered in the 1960's in the radio detection of extensive air showers induced by ultra high energy cosmic rays (UHECR), a new experimental…

The Fluorescence detector Array of Single-pixel Telescopes aims to deploy an array of simplified, autonomous fluorescence telescopes over an area of $\sim60,000$ km$^{2}$ to observe ultra-high energy cosmic rays. The unprecedented size of…

Instrumentation and Methods for Astrophysics · Physics 2025-10-28 Fraser Bradfield