Upper limit to the number of galactic sources of ultra-high-energy gamma-rays

1989 ◽  
Vol 8 (2) ◽  
pp. 159-160 ◽  
Author(s):  
D. J. Bird ◽  
R. W. Clay ◽  
P. G. Edwards
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Galactic Plane ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Upper Limits ◽  
Energy Gamma ◽  
Galactic Sources ◽  
Cosmic Ray Flux

AbstractThe extreme isotropy of cosmic ray events allows one to put upper limits on any possible non-isotropic contribution to the flux. In particular, one can investigate any excess of events which may be confined to the galactic plane. Such extra events would be expected from galactic ultra-high-energy (UHE) gamma-ray sources. Under the assumption of an isotropic cosmic ray flux, recent Buckland Park data place a 95% confidence level limit on the total southern hemisphere (declination −15° to −55°) flux of UHE gamma-rays at between 0.6 and 6 equivalent Cygnus X-3 sources, depending on assumptions concerning the gamma-ray spectrum.

Development of the Buckland Park Cosmic Ray Air Shower Array for Ultra High Energy Gamma Ray Astronomy

1986 ◽  
Vol 6 (3) ◽  
pp. 335-338 ◽  
Author(s):  
D. Ciampa ◽  
R. W. Clay ◽  
C. L. Corani ◽  
P. G. Edwards ◽  
J. R. Patterson
Keyword(s):  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Gamma Ray Astronomy ◽  
Air Shower ◽  
High Energy Gamma ◽  
Energy Gamma ◽  
Shower Array ◽  
Air Shower Array

AbstractThe Buckland Park air shower array is being developed particularly for use as an ultra-high-energy gamma ray astronomy telescope. The properties of this instrument are described with an emphasis on improvements being made to its angular resolution. Some early data are presented to illustrate the way in which the data obtained will be used.

Diffuse Gamma Rays of Galactic and Extragalactic Origin: Preliminary Results from EGRET

1996 ◽  
Vol 168 ◽  
pp. 279-288
Author(s):  
P. Sreekumar ◽  
D.A. Kniffen
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Emission Model ◽  
Diffuse Emission ◽  
Interstellar Gas ◽  
Cosmic Ray Interactions ◽  
Galactic Model ◽  
Energy Gamma

The all-sky survey in high energy gamma rays (E>30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma Ray Observatory provides for the first time an opportunity to examine in detail diffuse gamma-ray emission of extra-galactic origin. The observed diffuse emission at high galactic latitudes is generally assumed to have a galactic component arising from cosmic-ray interactions with the local interstellar gas and radiation, in addition to an isotropic component presumably of extragalactic origin. The galactic component can be estimated from a model of the interstellar medium and cosmic-ray distribution. Since the derived extragalactic spectrum depends very much on the success of our galactic model, the consistency of the galactic diffuse emission model is examined both spectrally and spatially with existing EGRET observations. In conjunction with this model, EGRET observations of the high latitude emission are used to examine the flux and spectrum of the residual extragalactic emission. This residual emission could be either truly diffuse in origin or could arise from accumulated emission from unresolved sources particularly in the light of EGRET observations showing the presence of numerous gamma-ray bright active galactic nuclei.

Search for Ultra High Energy Gamma Rays from Centaurus A

1990 ◽  
Vol 8 (3) ◽  
pp. 266-267 ◽  
Author(s):  
D. J. Bird ◽  
R. W. Clay
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Significant Excess ◽  
Show Evidence ◽  
Energy Gamma ◽  
Period Data ◽  
One Year ◽  
Centaurus A

AbstractAn analysis has been made of events recorded in one year from the direction of the active galaxy Centaurus A using the Buckland Park UHE gamma-ray telescope. No statistically significant excess was observed over this period. Data collected between 1984 and 1989 show evidence for an excess of events from this direction at shower sizes in the range of 2 × 105 to 5 × 105 particles.

scholarly journals High-energy gamma- and cosmic-ray observations with future space-based GAMMA-400 gamma-ray telescope

2019 ◽  
Vol 208 ◽  
pp. 14004 ◽  
Author(s):  
N.P. Topchiev ◽  
A.M. Galper ◽  
I.V. Arkhangelskaja ◽  
A.I. Arkhangelskiy ◽  
A.V. Bakaldin ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Electron Positron ◽  
Future Space ◽  
Long Time ◽  
Energy Gamma ◽  
Celestial Sphere ◽  
Better Than

The future space-based GAMMA-400 gamma-ray telescope will be installed on the Navigator platform of the Russian Astrophysical Observatory. A highly elliptical orbit will provide observations for 7-10 years of many regions of the celestial sphere continuously for a long time (~ 100 days). GAMMA-400 will measure gamma-ray fluxes in the energy range from ~ 20 MeV to several TeV and electron + positron fluxes up to ~ 20 TeV. GAMMA-400 will have an excellent separation of gamma rays from the background of cosmic rays and electrons + positrons from protons and an unprecedented angular (~ 0.01° at Eγ = 100 GeV) and energy (~ 1% at Eγ = 100 GeV) resolutions better than for Fermi-LAT, as well as ground-based facilities, by a factor of 5-10. Observations of GAMMA-400 will provide new fundamental data on discrete sources and spectra of gamma-ray emission and electrons + positrons, as well as the nature of dark matter.

A search for prompt ultra-high-energy gamma rays from supernova 1987a

1987 ◽  
Vol 7 (1) ◽  
pp. 73-74 ◽  
Author(s):  
D. J. Bird ◽  
T. E. G. Bruce ◽  
D. Ciampa ◽  
R. W. Clay ◽  
C. L. Corani ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Large Magellanic Cloud ◽  
High Energy ◽  
Ultra High Energy ◽  
Air Shower ◽  
High Energy Gamma ◽  
Supernova 1987A ◽  
Upper Limits ◽  
Energy Gamma ◽  
Shower Array

AbstractA search has been made using the Buckland Park air shower array for evidence of any excess of events from the direction of the recent supernova in the Large Magellanic Cloud. Upper limits resulting from this search and their significance are discussed in this paper.

scholarly journals Upper limits on very-high-energy gamma-ray emission from core-collapse supernovae observed with H.E.S.S.

2019 ◽  
Vol 626 ◽  
pp. A57 ◽  
Author(s):  
◽  
H. Abdalla ◽  
F. Aharonian ◽  
F. Ait Benkhali ◽  
E. O. Angüner ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Core Collapse ◽  
Upper Limits ◽  
Very High Energy ◽  
Energy Gamma ◽  
Stereoscopic System ◽  
Gamma Ray Emission ◽  
Progenitor Stars

Young core-collapse supernovae with dense-wind progenitors may be able to accelerate cosmic-ray hadrons beyond the knee of the cosmic-ray spectrum, and this may result in measurable gamma-ray emission. We searched for gamma-ray emission from ten supernovae observed with the High Energy Stereoscopic System (H.E.S.S.) within a year of the supernova event. Nine supernovae were observed serendipitously in the H.E.S.S. data collected between December 2003 and December 2014, with exposure times ranging from 1.4 to 53 h. In addition we observed SN 2016adj as a target of opportunity in February 2016 for 13 h. No significant gamma-ray emission has been detected for any of the objects, and upper limits on the >1 TeV gamma-ray flux of the order of ~10−13 cm−2s−1 are established, corresponding to upper limits on the luminosities in the range ~2 × 1039 to ~1 × 1042 erg s−1. These values are used to place model-dependent constraints on the mass-loss rates of the progenitor stars, implying upper limits between ~2 × 10−5 and ~2 × 10−3 M⊙ yr−1 under reasonable assumptions on the particle acceleration parameters.

scholarly journals Monitoring of the atmospheric electric field and cosmic-ray flux for the interpretation of results in high-energy astroparticle physics experiments

2019 ◽  
Vol 197 ◽  
pp. 03001
Author(s):  
Ashot Chilingarian ◽  
Johannes Knapp ◽  
Mary Zazyan
Keyword(s):  
Electric Fields ◽  
Gamma Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Energy Spectra ◽  
Astroparticle Physics ◽  
Primary Particles ◽  
Energy Gamma ◽  
Physics Experiments ◽  
Cosmic Ray Flux

Atmospheric electric fields influence experiments using the atmosphere as a detector for very weak fluxes of highest-energy gamma rays and protons/nuclei coming from galactic and extragalactic sources. Multiplication of electrons and gamma rays in strong atmospheric electric fields change particle numbers and energy spectra of the secondary shower particles and consequently influence the reconstructed properties of the primary particles. Here, we present a MC study using the CORSIKA package to explore and quantify these effects.

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