scholarly journals Cygnus X-3 and Other Ultra-High-Energy γ-Ray Sources

1987 ◽  
Vol 125 ◽  
pp. 521-533
Author(s):  
John J. Barnard
Keyword(s):  
Theoretical Models ◽  
High Energy ◽  
Current Status ◽  
Ultra High Energy ◽  
X Ray ◽  
Air Shower ◽  
Γ Rays ◽  
Γ Ray ◽  
High Energy Particles

Recently, several binary X-ray sources have been found to be sources of ultra high energy γ-ray emission. Air shower observations indicate photon energies >∼ 1015 eV. We review the current status of observations from the source Cygnus X-3, and compare this data with that from the sources Hercules X-1, Vela X-1, and LMC X-4. Current theoretical models for the production of γ-rays and the acceleration of high energy particles are discussed and the consequences for the evolution of such systems are examined.

Ultra-High Energy γ-Ray Astronomy using an EAS Array: Search for Emission From 100 MeV Sources

1984 ◽  
Vol 5 (4) ◽  
pp. 586-589 ◽  
Author(s):  
R. J. Protheroe ◽  
R. W. Clay
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Significant Excess ◽  
Extensive Air Shower ◽  
Air Shower ◽  
Secondary Particles ◽  
Γ Rays ◽  
Γ Ray ◽  
The University

Recently, a new branch of astronomy has emerged following the detection of ultra-high energy (UHE) γ-ray emission from Cygnus X-3 by Samorski and Stamm (1983). This discovery was made using the extensive air shower (EAS) array of the University of Kiel, Germany. Such arrays are designed to detect EAS, the cascades of secondary particles (mainly electrons and protons), which are generated in the atmosphere by the interaction of cosmic ray nuclei of energy greater than ˜ 1015 eV. These arrays are also sensitive to EAS initiated by primary γ-rays and, depending on their design, have angular resolutions as good as the SAS-II and COS-B γ-ray telescopes which operated at ˜ 100 MeV energies. At present, there is no effective way to veto proton or nucleus-initiated EAS and so one must look for a significant excess of EAS from within a cone of resolution centred on a suspected source direction.

scholarly journals Pulsed γ-ray emission from magnetar 1E 2259+586

2012 ◽  
Vol 8 (S291) ◽  
pp. 555-557
Author(s):  
J. H. K. Wu ◽  
C. Y. Hui ◽  
R. H. H. Huang ◽  
A. K. H. Kong ◽  
K. S. Cheng ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Theoretical Models ◽  
High Energy ◽  
Large Area ◽  
Strong Magnetic Fields ◽  
X Ray ◽  
Γ Rays ◽  
Γ Ray ◽  
High Energy Emission ◽  
Intensive Search

AbstractAnomalous X-ray pulsars (AXPs) are thought to be magnetars which are young isolated neutron stars with extremely strong magnetic fields of >1014 Gauss. Their tremendous magnetic fields inferred from the spin parameters provide a huge energy reservoir to power the observed X-ray emission. High-energy emission above 0.3 MeV has never been detected despite intensive search. Here, we present the possible Fermi Large Area Telescope (LAT) detection of γ-ray pulsations above 200 MeV from the AXP, 1E 2259+586, which puts the current theoretical models of γ-ray emission mechanisms of magnetars into challenge. We speculate that the high-energy γ-rays originate from the outer magnetosphere of the magnetar.

scholarly journals Ultra-high-energy cosmic rays in the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 432-433
Author(s):  
R. J. Protheroe
Keyword(s):  
Synchrotron Radiation ◽  
High Energy ◽  
Magellanic Clouds ◽  
Ultra High Energy ◽  
Microwave Background ◽  
X Ray ◽  
High Energy Cosmic Rays ◽  
Γ Rays ◽  
Γ Ray ◽  
X Ray Binaries

Ultra-high-energy (UHE) γ-rays have been detected from several X-ray binaries. UHE γ-rays from sources in the LMC will interact in the microwave background producing electrons which emit synchrotron radiation in the X-ray and γ-ray bands. This radiation might be observable.

Young radio sources at high-energies and the γ-ray CSO PKS 1718–649

2018 ◽  
Vol 14 (S342) ◽  
pp. 176-179
Author(s):  
Giulia Migliori
Keyword(s):  
Radio Galaxy ◽  
Radio Galaxies ◽  
High Energy ◽  
Radio Sources ◽  
Host Galaxies ◽  
X Ray ◽  
High Energies ◽  
Γ Rays ◽  
Γ Ray ◽  
High Energy Emission

AbstractObservations at high-energies are important to define the first stages of the evolution of extragalactic radio sources and to characterize the interstellar medium of their host galaxies. In some of the X-ray-observed Compact Symmetric Objects (CSOs, among the youngest and most compact radio galaxies), we measured values of the total hydrogen column densities large enough to slow or prevent the radio source growth. The γ-ray window has the potential to constrain the non-thermal contribution of jets and lobes to the total high-energy emission. However, so far, young radio sources remain elusive in γ-rays, with only a handful of detections (or candidates) reported by Fermi. I present our γ-ray study of the CSO PKS 1718–649, and draw comparison with the restarted, γ-ray detected, radio galaxy 3C 84.

The spectrum of γ rays in the energy range 1011 to 1013 eV at an atmospheric depth of 200 g/cm2, and pion generation in high-energy nucleon interactions

1968 ◽  
Vol 46 (10) ◽  
pp. S700-S705 ◽  
Author(s):  
A. V. Apanasenko ◽  
L. T. Baradzei ◽  
E. A. Kanevskaya ◽  
V. V. Rykov ◽  
Yu. A. Smorodin ◽  
...  
Keyword(s):  
Energy Range ◽  
High Energy ◽  
Nucleon Interaction ◽  
Nuclear Emulsions ◽  
X Ray ◽  
Black Spots ◽  
Γ Rays ◽  
Γ Ray ◽  
Using Data ◽  
Electron Photon

The problem of the existence of a change of slope in the γ-ray spectrum in the atmosphere is of considerable interest in connection with conclusions about the change in the character of the nucleon interaction. Up to now this problem has not been solved experimentally. In this report the γ-ray spectrum in the 1011–1013 eV energy range has been obtained using data from X-ray films and nuclear emulsions exposed on board an airplane at a pressure of 200 g/cm2. The total exposure was 425 hours∙m2. The energies of the electron–photon cascades initiated by γ rays were determined in the X-ray films by measuring the photometric densities of the black spots, and in nuclear emulsions by counting the electron tracks near the cascade axis. The integral spectrum has a power-law form with an exponent of 1.7–1.9. A change in slope in the spectrum was not found. Thus, a mechanism generating pions with energies proportional to the initial nucleon energies exists up to nucleon energies of ~1014 eV. The analysis of the accompaniment of γ rays by "families" shows that in one-third of the cases the energy of the most energetic π0 meson is at least five times that of the next π0 meson. In the remaining two-thirds of the cases the π0 mesons have comparable energies.

scholarly journals VHE GAMMA-RAYS FROM GALACTIC X-RAY BINARY SYSTEMS

2008 ◽  
Vol 17 (10) ◽  
pp. 1849-1858 ◽  
Author(s):  
J. M. PAREDES
Keyword(s):  
Gamma Rays ◽  
Binary Systems ◽  
High Energy ◽  
X Ray ◽  
Very High Energy ◽  
Γ Rays ◽  
Γ Ray ◽  
Tev Gamma Rays ◽  
X Ray Binaries ◽  
Very High

The detection of TeV gamma-rays from LS 5039 and the binary pulsar PSR B1259–63 by HESS, and from LS I +61 303 and the stellar-mass black hole Cygnus X-1 by MAGIC, provides clear evidence of very efficient acceleration of particles to multi-TeV energies in X-ray binaries. These observations demonstrate the richness of nonthermal phenomena in compact galactic objects containing relativistic outflows or winds produced near black holes and neutron stars. I review here some of the main observational results on very high energy (VHE) γ-ray emission from X-ray binaries, as well as some of the proposed scenarios to explain the production of VHE γ-rays. I put special emphasis on the flare TeV emission, suggesting that the flaring activity might be a common phenomena in X-ray binaries.

Very High Energy γ-rays from AGN

2002 ◽  
Vol 19 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Tadashi Kifune
Keyword(s):  
Electromagnetic Radiation ◽  
Active Galactic Nuclei ◽  
Energy Band ◽  
Galactic Nuclei ◽  
High Energy ◽  
Current Status ◽  
Very High Energy ◽  
Γ Rays ◽  
Γ Ray ◽  
Very High

AbstractEvidence of TeV γ-ray emission has been found for only a handful of active galactic nuclei, with detailed investigations limited to the blazars Mrk 421 and Mrk 501. TeV γ-ray astronomy, as the highest energy band, provides important information that is hard to obtain from longer wavelength electromagnetic radiation. The current status of TeV γ-ray studies of active galactic nuclei is summarized and our understanding of the high energy phenomena taking place in active galactic nuclei is outlined, with the prospects for future TeV γ-ray observations also considered.

scholarly journals Pulsar (and X-Star) Emission from the Magnetosphere of a Collapsed Star

1971 ◽  
Vol 46 ◽  
pp. 460-470
Author(s):  
Bruno Coppi ◽  
Attilio Ferrari
Keyword(s):  
Special Reference ◽  
Crab Nebula ◽  
Nonthermal Plasma ◽  
High Energy ◽  
Physical Characteristics ◽  
Pulsar Emission ◽  
X Ray ◽  
Γ Rays ◽  
The Crab Nebula ◽  
High Energy Particles

We propose nonthermal plasma mechanisms to account for the most evident physical characteristics of pulsar emission, including the production of X- and γ-rays and the acceleration of high-energy particles. Special reference to the Crab Nebula pulsar (NP 0532) is made and an application of the same model to other non-thermal X-ray sources is suggested.

scholarly journals Cosmic Ray Acceleration and γ Ray Induced by the Interaction of the Ejecta of SN1987A with the Magnetized Cloud

1990 ◽  
Vol 140 ◽  
pp. 359-360
Author(s):  
Hitoshi Hanami
Keyword(s):  
Physical Process ◽  
Interaction Model ◽  
Cosmic Ray ◽  
High Energy ◽  
Reverse Shock ◽  
X Ray ◽  
Acceleration Mechanism ◽  
Cosmic Ray Acceleration ◽  
Γ Rays ◽  
Γ Ray

We have studied the high energy physical process related to the cosmic ray acceleration for SN1987A. The X-ray flare observed by Ginga satellite (Makino 1988) and TeV γ-rays reported by the JANZOS collaboration (Bond et al. 1988) occurred in January, 1988. These events may be explained by the interaction of the supernova ejecta with the surrounding cloud, which induces the thermalization of shocked material and the acceleration of cosmic ray on the reverse shock at the front of cloud. Especially, the soft X-ray emission from SN1987A is well described by the interaction model of the ejecta with the circumstellar medium (Masai et al. 1988, and Yoshida and Hanami 1988). It seems to be natural to consider that the origin of the γ-ray is connected with that of the X-ray flare, since they had occurred at same time. Then, we consider about the relation of this acceleration mechanism and the evolution scenario of the progenitor.

scholarly journals LARGE SCALE AIR SHOWER SIMULATIONS AND THE SEARCH FOR NEW PHYSICS AT AUGER

2004 ◽  
Vol 19 (22) ◽  
pp. 3729-3760 ◽  
Author(s):  
ALESSANDRO CAFARELLA ◽  
CLAUDIO CORIANÒ ◽  
ALON E. FARAGGI
Keyword(s):  
Large Scale ◽  
Geometrical Structure ◽  
Theoretical Models ◽  
High Energy ◽  
New Physics ◽  
Ultra High Energy ◽  
Missing Energy ◽  
High Energy Cosmic Rays ◽  
Air Shower ◽  
Statistical Fluctuations

Large scale airshower simulations around the GZK cutoff are performed. An extensive analysis of the behaviour of the various subcomponents of the cascade is presented. We focus our investigation both on the study of total and partial multiplicities along the entire atmosphere and on the geometrical structure of the various cascades, in particular on the lateral distributions. The possibility of detecting new physics in Ultra High Energy Cosmic Rays (UHECR) at AUGER is also investigated. We try to disentangle effects due to standard statistical fluctuations in the first proton impact in the shower formation from the underlying interaction and comment on these points. We argue that theoretical models predicting large missing energy may have a chance to be identified, once the calibration errors in the energy measurements are resolved by the experimental collaborations, in measurements of inclusive multiplicities.

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