Physical Sciences: Two New Point Sources of High Energy Cosmic Gamma Rays

Nature ◽  
1971 ◽  
Vol 231 (5302) ◽  
pp. 372-375 ◽  
Author(s):  
G. M. FRYE ◽  
P. A. ALBATS ◽  
A. D. ZYCH ◽  
J. A. STAIB ◽  
V. D. HOPPER ◽  
...  
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
Point Sources ◽  
Physical Sciences

scholarly journals Modeling Gamma-Ray SEDs and Angular Extensions of Extreme TeV Blazars from Intergalactic Proton-Initiated Cascades in Contemporary Astrophysical EGMF Models

Universe ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 220
Author(s):  
Emil Khalikov
Keyword(s):  
Gamma Rays ◽  
Large Scale ◽  
Gamma Ray ◽  
High Energy ◽  
Cascade Model ◽  
Point Sources ◽  
Spectral Energy ◽  
Observation Data ◽  
Cherenkov Telescopes ◽  
The Universe

The intrinsic spectra of some distant blazars known as “extreme TeV blazars” have shown a hint at an anomalous hardening in the TeV energy region. Several extragalactic propagation models have been proposed to explain this possible excess transparency of the Universe to gamma-rays starting from a model which assumes the existence of so-called axion-like particles (ALPs) and the new process of gamma-ALP oscillations. Alternative models suppose that some of the observable gamma-rays are produced in the intergalactic cascades. This work focuses on investigating the spectral and angular features of one of the cascade models, the Intergalactic Hadronic Cascade Model (IHCM) in the contemporary astrophysical models of Extragalactic Magnetic Field (EGMF). For IHCM, EGMF largely determines the deflection of primary cosmic rays and electrons of intergalactic cascades and, thus, is of vital importance. Contemporary Hackstein models are considered in this paper and compared to the model of Dolag. The models assumed are based on simulations of the local part of large-scale structure of the Universe and differ in the assumptions for the seed field. This work provides spectral energy distributions (SEDs) and angular extensions of two extreme TeV blazars, 1ES 0229+200 and 1ES 0414+009. It is demonstrated that observable SEDs inside a typical point spread function of imaging atmospheric Cherenkov telescopes (IACTs) for IHCM would exhibit a characteristic high-energy attenuation compared to the ones obtained in hadronic models that do not consider EGMF, which makes it possible to distinguish among these models. At the same time, the spectra for IHCM models would have longer high energy tails than some available spectra for the ALP models and the universal spectra for the Electromagnetic Cascade Model (ECM). The analysis of the IHCM observable angular extensions shows that the sources would likely be identified by most IACTs not as point sources but rather as extended ones. These spectra could later be compared with future observation data of such instruments as Cherenkov Telescope Array (CTA) and LHAASO.

scholarly journals Search for astrophysical PeV gamma rays from point sources with Carpet-2

2019 ◽  
Vol 207 ◽  
pp. 03004 ◽  
Author(s):  
D. D. Dzhappuev ◽  
I. M. Dzaparova ◽  
E. A. Gorbacheva ◽  
I. S. Karpikov ◽  
M. M. Khadzhiev ◽  
...  
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
Point Sources ◽  
Muon Detector ◽  
Air Shower ◽  
Early Results ◽  
Upper Limits ◽  
Shower Array ◽  
Air Shower Array

Early results of the search for Eγ > 1 PeV cosmic photons from point sources with the data of Carpet–2, an air-shower array equipped with a 175 m2 muon detector, are presented. They include 95% CL upper limits on PeV photon fluxes from stacked directions of high-energy IceCube neutrino events and from four predefined sources, Crab, Cyg X-3, Mrk 421 and Mrk 501. An insignificant excess of events from Mrk 421 will be further monitored. Prospects of the use of the upgraded installation, Carpet–3 (410 m2 muon detector), scheduled to start data taking in 2019, for searches of Eγ > 100 TeV photons, are briefly discussed.

SEARCH FOR BURST SIGNALS FROM POINT SOURCES

2005 ◽  
Vol 20 (29) ◽  
pp. 6962-6964
Author(s):  
◽  
P. LE COULTRE
Keyword(s):  
Gamma Rays ◽  
Time Windows ◽  
High Energy ◽  
Muon Flux ◽  
Point Sources ◽  
Source Position ◽  
High Energy Gamma ◽  
Sky Survey ◽  
Energy Gamma ◽  
Underground Muon

A sky survey for flaring point sources emitting high energy gamma rays has been performed with the L 3+ C underground muon spectrometer at LEP, CERN. Data were collected from mid July to October 1999 and from April to November 2000. No signal excesses in any direction have been found with muons above 20, 30, 50 and 100 GeV within one day and longer time windows. The steady muon flux sensitivity is of the order of a few times 10-9 cm-2 s-1 for muon energies above 20 GeV, and between 2 × 10-11 and 5 × 10-10 cm -2 s -1 for muon energies above 20 GeV depending on the source position.

Search for point sources of high-energy cosmic gamma rays

1968 ◽  
Vol 46 (10) ◽  
pp. S425-S426 ◽  
Author(s):  
J. P. Delvaille ◽  
P. Albats ◽  
K. I. Greisen ◽  
H. B. Ögelman
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Galactic Disk ◽  
Crab Nebula ◽  
High Energy ◽  
Point Sources ◽  
Photon Flux ◽  
Upper Limits ◽  
Cas A ◽  
The Crab Nebula

A balloon-borne photographic spark chamber was flown at a pressure of 10 g cm−2 on 14 April 1966 from Holloman A.F.B., New Mexico. Upper limits were obtained on gamma-ray fluxes above 1 GeV from various discrete sources including Cyg A, Cas A, and the Crab nebula. Also a measurement was made on the average photon flux above 1 GeV from a portion of the galactic disk.

scholarly journals The GRAND project and GRANDProto300 experiment

2019 ◽  
Vol 210 ◽  
pp. 06007
Author(s):  
Olivier Martineau-Huynh
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
High Energy ◽  
Point Sources ◽  
Ultra High Energy ◽  
Air Showers ◽  
High Energy Cosmic Rays ◽  
Complete Measurement ◽  
Neutrino Astronomy ◽  
The Universe

The Giant Array for Neutrino Detection (GRAND) is a proposal for a giant observatory of ultra-high energy cosmic particles (neutrinos, cosmic rays and gamma rays). It will be composed of twenty subarrays of 10 000 antennas each, totaling a detection area of 200 000 km2. GRAND will reach unprecedented sensitivity to neutrinos allowing to detect cosmogenic neutrinos while its sub-degree angular resolution will also make it possible to hunt for point sources and possibly start neutrino astronomy. Combined with its gigantic exposure to ultra-high energy cosmic rays and gamma rays, GRAND will be a powerful tool to solve the century-long mistery of the nature and origin of the particles with highest energy in the Universe. On the path to GRAND, the GRANDProto300 experiment will be deployed in 2020 over a total area of 200 km2. It primarly aims at validating the detection concept of GRAND, but also proposes a rich science program centered on a precise and complete measurement of the air showers initiated by cosmic rays with energies between 1016.5 and 1018 eV, a range where we expect to observe the transition between the Galactic and extra-galactic origin of cosmic rays.

Search for point sources of neutral cosmic rays above 1012 eV

1968 ◽  
Vol 46 (10) ◽  
pp. S81-S83 ◽  
Author(s):  
Hugh S. Tornabene ◽  
Frank J. Cusimano
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Angular Resolution ◽  
High Energy ◽  
Point Sources ◽  
Half Maximum ◽  
Air Showers ◽  
Arrival Times ◽  
Right Ascension ◽  
Cerenkov Light

A new installation for the detection of Cerenkov light from extensive air showers is being used to search for point sources of high-energy neutral cosmic rays. By measuring the relative arrival times of the Cerenkov light front at four well-spaced independent light detectors, an area of sky is examined simultaneously, with angular resolution near 1.5° half-width at half-maximum and energy threshold to gamma rays near 2 × 1012 eV. Results from preliminary scans of 3C144, 3C157, 3C219, 3C274, 3C295, and the constellation of Leo near declination 20° and right ascension 1100 h are given.

Quasi-monochromatic and polarized high-energy gamma rays

1964 ◽  
Vol 83 (5) ◽  
pp. 3-34 ◽  
Author(s):  
F.R. Arutyunyan ◽  
V.A. Tumanyan
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
High Energy Gamma ◽  
Energy Gamma

scholarly journals Recent advances in radiation detection technologies enabled by metal-halide perovskites

2021 ◽  
Author(s):  
Tiebin Yang ◽  
Feng Li ◽  
Rongkun Zheng
Keyword(s):  
Gamma Rays ◽  
Performance Optimization ◽  
Radiation Detection ◽  
High Energy ◽  
Device Performance ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Halide Perovskites ◽  
Alpha Beta ◽  
Detection Technologies

Perovskite halides hold great potential for high-energy radiation detection. Recent advancements in detecting alpha-, beta-, X-, and gamma-rays by perovskite halides are reviewed and an outlook on the device performance optimization is provided.

Propagation of cosmic rays and their secondaries in the intracluster medium

2020 ◽  
Vol 15 (S359) ◽  
pp. 178-179
Author(s):  
Saqib Hussain ◽  
Rafael Alves Batista ◽  
Elisabete Maria de Gouveia Dal Pino ◽  
Klaus Dolag
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Intergalactic Medium ◽  
Three Dimensional ◽  
High Energy ◽  
Intracluster Medium ◽  
High Energy Cosmic Rays ◽  
Test Particles

AbstractWe present results of the propagation of high-energy cosmic rays (CRs) and their secondaries in the intracluster medium (ICM). To this end, we employ three-dimensional cosmological magnetohydrodynamical simulations of the turbulent intergalactic medium to explore the propagation of CRs with energies between 1014 and 1019 eV. We study the interaction of test particles with this environment considering all relevant electromagnetic, photohadronic, photonuclear, and hadronuclear processes. Finally, we discuss the consequences of the confinement of high-energy CRs in clusters for the production of gamma rays and neutrinos.

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