scholarly journals An Upper Limit on the Strength of the Extragalactic Magnetic Field from Ultra-high-energy Cosmic-Ray Anisotropy

2018 ◽  
Vol 861 (1) ◽  
pp. 3 ◽  
Author(s):  
J. D. Bray ◽  
A. M. M. Scaife
2019 ◽  
Vol 216 ◽  
pp. 02012
Author(s):  
T. Marshalkina ◽  
P.A. Bezyazeekov ◽  
N.M. Budnev ◽  
D. Chernykh ◽  
O. Fedorov ◽  
...  

The Tunka Radio Extension (Tunka-Rex) is a digital antenna array for the detection of radio emission from cosmic-ray air showers in the frequency band of 30 to 80 MHz and for primary energies above 100 PeV. The standard analysis of Tunka-Rex includes events with zenith angle of up to 50?. This cut is determined by the efficiency of the external trigger. However, due to the air-shower footprint increasing with zenith angle and due to the more efficient generation of radio emission (the magnetic field in the Tunka valley is almost vertical), there are a number of ultra-high-energy inclined events detected by Tunka-Rex. In this work we present a first analysis of a subset of inclined events detected by Tunka-Rex. We estimate the energies of the selected events and test the efficiency of Tunka-Rex antennas for detection of inclined air showers.


2019 ◽  
Vol 210 ◽  
pp. 04004
Author(s):  
Martin Erdmann ◽  
Lukas Geiger ◽  
David Schmidt ◽  
Martin Urban ◽  
Marcus Wirtz

We present a novel approach to search for origins of ultra-high energy cosmic rays. In a simultaneous fit to all observed cosmic rays we use the galactic magnetic field as a mass spectrometer and adapt the nuclear charges such that their extragalactic arrival directions are concentrated in as few directions as possible. During the fit the nuclear charges are constraint by the individual energy and shower depth measurements. We show in a simulated astrophysical scenario that source directions can be reconstructed even within a substantial isotropic background.


2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Marcus Wirtz ◽  
Teresa Bister ◽  
Martin Erdmann

AbstractWe present a novel method to search for structures of coherently aligned patterns in ultra-high energy cosmic-ray arrival directions simultaneously across the entire sky. This method can be used to obtain information on the Galactic magnetic field, in particular the integrated component perpendicular to the line of sight, from cosmic-ray data only. Using a likelihood-ratio approach, neighboring cosmic rays are related by rotatable, elliptically shaped density distributions and the significance of their alignment with respect to circular distributions is evaluated. In this way, a vector field tangential to the celestial sphere is fitted which approximates the local deflections in cosmic magnetic fields if significant deflection structures are detected. The sensitivity of the method is evaluated on the basis of astrophysical simulations of the ultra-high energy cosmic-ray sky, where a discriminative power between isotropic and signal-induced scenarios is found.


2019 ◽  
Vol 210 ◽  
pp. 02001
Author(s):  
Sergey Ostapchenko

The differences between contemporary Monte Carlo generators of high energy hadronic interactions are discussed and their impact on the interpretation of experimental data on ultra-high energy cosmic rays (UHECRs) is studied. Key directions for further model improvements are outlined. The prospect for a coherent interpretation of the data in terms of the UHECR composition is investigated.


2011 ◽  
Vol 20 (03) ◽  
pp. 299-317
Author(s):  
E. STRAZZERI ◽  
O. CATALANO ◽  
B. SBARUFATTI

In the context of detection of Ultra High Energy Cosmic Ray (UHECR) showers from space the details of fluorescence light production and transmission in the atmosphere are given. An analytical model of the fluorescence yield, in dependence on nitrogen molecular parameters and the atmospheric conditions, is presented. Seasonal and geographical variations of the total fluorescence photon yield between 300 nm and 400 nm in air excited by 0.85 MeV electrons are shown as a function of the altitude, using different atmospheric models. In the frame of a satellite-based UHECR experiment the fluorescence yield has been corrected by the overall atmospheric transmission which takes into account, in the simplest approximation, the wavelength-dependent scattering and absorption of the fluorescence light from air molecules, from stratospheric ozone, and from aerosol. The effect of the atmospheric attenuation on the fluorescence yield is shown as a function of the altitude of the emission point of light.


2021 ◽  
Vol 128 ◽  
pp. 102564
Author(s):  
Lukas Merten ◽  
Margot Boughelilba ◽  
Anita Reimer ◽  
Paolo Da Vela ◽  
Serguei Vorobiov ◽  
...  

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