Search for Ultra--High-Energy Point-Source Emission over Various Timescales

1994 ◽  
Vol 423 ◽  
pp. 714 ◽  
Author(s):  
S. Biller ◽  
D. E. Alexandreas ◽  
G. E. Allen ◽  
D. Berley ◽  
R. L. Burman ◽  
...  
Keyword(s):  
Point Source ◽  
High Energy ◽  
Ultra High Energy ◽  
Energy Point ◽  
Source Emission

scholarly journals Search for point sources of ultra-high-energy photons with the Telescope Array surface detector

2020 ◽  
Vol 492 (3) ◽  
pp. 3984-3993 ◽  
Author(s):  
R U Abbasi ◽  
M Abe ◽  
T Abu-Zayyad ◽  
M Allen ◽  
R Azuma ◽  
...  
Keyword(s):  
Point Source ◽  
Cosmic Ray ◽  
High Energy ◽  
Point Sources ◽  
Ultra High Energy ◽  
Telescope Array ◽  
Air Shower ◽  
Upper Limits ◽  
Surface Detector ◽  
Blind Search

ABSTRACT The surface detector (SD) of the Telescope Array (TA) experiment allows us to detect indirectly photons with energies of the order of 1018 eV and higher, and to separate photons from the cosmic ray background. In this paper, we present the results of a blind search for point sources of ultra-high-energy (UHE) photons in the Northern sky using the TA SD data. The photon-induced extensive air showers are separated from the hadron-induced extensive air shower background by means of a multivariate classifier based upon 16 parameters that characterize the air shower events. No significant evidence for the photon point sources is found. The upper limits are set on the flux of photons from each particular direction in the sky within the TA field of view, according to the experiment’s angular resolution for photons. The average 95 per cent confidence level upper-limits for the point-source flux of photons with energies greater than 1018, 1018.5, 1019, 1019.5 and 1020 eV are 0.094, 0.029, 0.010, 0.0073 and 0.0058 km−2yr−1, respectively. For energies higher than 1018.5 eV, the photon point-source limits are set for the first time. Numerical results for each given direction in each energy range are provided as a supplement to this paper.

scholarly journals LIMIT ON UHE NEUTRINO FLUXES FROM THE PIERRE AUGER OBSERVATORY

2013 ◽  
Vol 53 (A) ◽  
pp. 756-759
Author(s):  
S. Maldera
Keyword(s):  
Point Source ◽  
High Energy ◽  
Time Structure ◽  
Pierre Auger Observatory ◽  
Tau Leptons ◽  
Ultra High Energy ◽  
Tau Neutrinos ◽  
Surface Detector ◽  
Recorded Data ◽  
Neutrino Fluxes

The surface detector of the Pierre Auger Observatory is sensitive to Ultra High Energy (UHE) neutrinos. Neutrinos of all flavors can interact in the atmosphere producing inclined showers near the ground. Moreover, ultra high energy Earth-skimming tau neutrinos can be observed through the detection of showers induced by the decay of tau leptons created by interactions in the Earth’s crust. In both cases, neutrino showers can be identified through the time structure of the signals in the surface detector stations. Two sets of identification criteria have been designed to search for down-going and up-going neutrinos in the recorded data, with no candidates found. We will discuss the identification criteria used, and we will present the corresponding limits on the diffuse and point source neutrino fluxes.

A search of the northern sky for ultra-high-energy point sources

1991 ◽  
Vol 383 ◽  
pp. L53 ◽  
Author(s):  
D. E. Alexandreas ◽  
D. Berley ◽  
S. Biller ◽  
R. L. Burman ◽  
D. R. Cady ◽  
...  
Keyword(s):  
High Energy ◽  
Point Sources ◽  
Ultra High Energy ◽  
Energy Point

Ultra-high-energy lithium-ion batteries enabled by aligned structured thick electrode design

Rare Metals ◽  
2021 ◽  
Author(s):  
Chao-Chao Zhou ◽  
Zhi Su ◽  
Xin-Lei Gao ◽  
Rui Cao ◽  
Shi-Chun Yang ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
High Energy ◽  
Electrode Design ◽  
Ultra High Energy ◽  
Thick Electrode

scholarly journals Planck Neutrinos as Ultra High Energy Cosmic Rays

2020 ◽  
Vol 29 (1) ◽  
pp. 40-46
Author(s):  
Dmitri L. Khokhlov
Keyword(s):  
Black Holes ◽  
Cosmic Rays ◽  
Standard Model ◽  
Active Galactic Nuclei ◽  
Planck Scale ◽  
Galactic Nuclei ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
The Standard Model

AbstractThe studied conjecture is that ultra high energy cosmic rays (UHECRs) are hypothetical Planck neutrinos arising in the decay of the protons falling onto the gravastar. The proton is assumed to decay at the Planck scale into positron and four Planck neutrinos. The supermassive black holes inside active galactic nuclei, while interpreted as gravastars, are considered as UHECR sources. The scattering of the Planck neutrinos by the proton at the Planck scale is considered. The Planck neutrinos contribution to the CR events may explain the CR spectrum from 5 × 1018 eV to 1020 eV. The muon number in the Planck neutrinos-initiated shower is estimated to be larger by a factor of 3/2 in comparison with the standard model that is consistent with the observational data.

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