Ground-based Gamma-ray Astronomy

1993 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
R.W. Clay ◽  
B.R. DawSOn

AbstractGround-based gamma-ray astronomy has slowly developed over the past quarter of a century to a position now where a number of sources are known to produce gamma-rays in the energy range 1011eV to 1018eV. The observations are difficult, with exceptional signal to noise problems, but improved techniques are now allowing observers to proceed with confidence. In this paper the physical bases of the observations are emphasised to show the important issues in the field and the present state of the observations is indicated.

2005 ◽  
Vol 20 (29) ◽  
pp. 7016-7019 ◽  
Author(s):  
A. MISHEV ◽  
S. MAVRODIEV ◽  
J. STAMENOV

We present a new method for ground based gamma ray astronomy based only on atmospheric Cherenkov light flux analysis. The Cherenkov light flux densities in extensive air showers initiated by different primaries are simulated in the energy range 100 GeV – 100 PeV for different primaries using the CORSIKA 6.003 code at (536 g/cm2). An approximation of lateral distribution of Cherenkov light flux densities in EAS is obtained using a nonlinear fit such as Breit-Wigner. The simulated and reconstructed events are compared and the accuracy in energy and primary mass reconstruction are obtained.


Nearly twenty years ago, G. D. Rochester and I organized a Discussion Meeting here on the origin of the cosmic radiation. P art of that meeting was devoted to primary gamma rays, and this meeting was followed a few years later by a meeting devoted entirely to gamma ray astronomy. At that time gamma rays represented a ‘new window on the Universe’. Now it is the turn of neutrinos to move into that slot, although it must be said that neutrino astronomy is not as far on as gamma ray astronomy was at that stage. Nevertheless, the subject has started and has already thrown up some dramatic questions, questions of interest to both astronomer and elementary particle physicist. In the more conventional astronomies, the Sun appears to be quite well behaved, and reasonably understood, with the interests of many centring on more distant and ‘dramatic’ objects, such as supernovae and extragalactic sources. With neutrinos, however, supernovae seem to be well behaved — at the superficial level, at least and based on one event — but the Sun does not. The remarkable deficit in solar neutrino flux recorded by Davis and collaborators over the past decades has been confirmed and we look forward to hearing the details of these confirmations, as well as the energy dependence of the flux and its comparison with expectation.


1994 ◽  
Vol 144 ◽  
pp. 635-639
Author(s):  
J. Baláž ◽  
A. V. Dmitriev ◽  
M. A. Kovalevskaya ◽  
K. Kudela ◽  
S. N. Kuznetsov ◽  
...  

AbstractThe experiment SONG (SOlar Neutron and Gamma rays) for the low altitude satellite CORONAS-I is described. The instrument is capable to provide gamma-ray line and continuum detection in the energy range 0.1 – 100 MeV as well as detection of neutrons with energies above 30 MeV. As a by-product, the electrons in the range 11 – 108 MeV will be measured too. The pulse shape discrimination technique (PSD) is used.


1982 ◽  
Vol 199 (3) ◽  
pp. 585-596 ◽  
Author(s):  
J.M. Lavigne ◽  
M. Niel ◽  
G. Vedrenne ◽  
C. Doulade ◽  
G. Giordano ◽  
...  

2017 ◽  
Author(s):  
David Sarria ◽  
Francois Lebrun ◽  
Pierre-Louis Blelly ◽  
Remi Chipaux ◽  
Philippe Laurent ◽  
...  

Abstract. With a launch expected in 2018, the TARANIS micro-satellite is dedicated to the study of transient phenomena observed in association with thunderstorms. On-board the spacecraft, XGRE and IDEE are two instruments dedicated to study Terrestrial Gamma-ray Flashes (TGFs) and associated electron beams (TEBs). XGRE can detect electrons (energy range: 1 MeV to 10 MeV) and X/gamma-rays (energy range: 20 keV to 10 MeV), with a very high counting capability (about 10 million counts per second), and the ability to discriminate one type of particle from the other. The IDEE instrument is focused on electrons in the 80 keV to 4 MeV energy range, with the ability to estimate their pitch angles. Monte-Carlo simulations of the TARANIS instruments, using a preliminary model of the spacecraft, allow sensitive area estimates for both instruments. It leads to an averaged effective area of 425 cm2 for XGRE to detect X/gamma rays from TGFs, and the combination of XGRE and IDEE gives an average effective area of 255 cm2 to detect electrons/positrons from TEBs. We then compare these performances to RHESSI, AGILE, and Fermi GBM, using performances extracted from literature for the TGF case, and with the help of Monte-Carlo simulations of their mass models for the TEB case. Combining these data with with the help of the MC-PEPTITA Monte-Carlo simulations of TGF propagation in the atmosphere, we build a self-consistent model of the TGF and TEB detection rates of RHESSI, AGILE, and Fermi. It can then be used to estimate that TARANIS should detect about 225 TGFs/year and 25 TEBs/year.


1996 ◽  
Vol 169 ◽  
pp. 437-446 ◽  
Author(s):  
Hans Bloemen

Gamma-ray astronomy has become a rich field of research and matured significantly since the launch of NASA's Compton Gamma Ray Observatory in April 1991. Studies of the diffuse γ-ray emission of the Galaxy can now be performed in far more detail and extended into the MeV regime, including both continuum and line emission. These studies provide unique insight into various aspects of the interstellar medium, in particular of the cosmic-ray component. This paper gives a brief review on the diffuse Galactic γ-ray emission and summarizes early results and prospects from the Compton Observatory.


1971 ◽  
Vol 41 ◽  
pp. 73-74
Author(s):  
H. A. Mayer-Hasselwander ◽  
K. Pinkau ◽  
K. H. Schenkl ◽  
W. Voges ◽  
H. J. Schneider

The registration of gamma rays in a spark chamber has been simulated by Monte-Carlo-calculation technique. The spark chamber pictures of these gamma-ray events having a known energy and direction of incidence have been analysed for determinability of direction of incidence. The values obtained for angular resolution depending on energy are compared with values derived by other authors.


1992 ◽  
Vol 9 ◽  
pp. 599-599
Author(s):  
R D Davies ◽  
J M Hough

The South Pole air shower experiment (SPASE), a joint Bartol Research Institute and Leeds University project, has been operational since the austral summer of 1987/88. It is a cosmic ray telescope searching for cosmic gamma rays at energies up to 1000 TeV. Although it has a relatively small area (6800 m2), it is situated at an altitude of 2800 m and has a 24 hour coverage, making it very competitive. The angular resolution of 0.°8 at 200 TeV is state-of-the-art in gamma ray astronomy. The astronomical programme includes searches for gamma ray sources, searches for anisotropy in the cosmic ray sky and measuring the energy spectrum over the range 1014-1016 eV.


Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Alexandru Mihailescu ◽  
Gheorghe Cata-Danil

AbstractFor the first time discrete gamma-rays following the nuclear reaction 170Er(p,n)170Tm with enriched target were measured with a high resolution GeHP spectrometer. Protons delivered by the Bucharest FN Tandem Van de Graaff accelerator bombarded a thin self-supporting film of enriched erbium. Measured γ-ray energies (Eγ), their relative intensities (Iγ) and corresponding excitation functions for the beam energy range 2.0–3.6 MeV are reported in the present work. The measured excitation functions were fairly well reproduced by compound nucleus calculations based on the Hauser-Feshbach formalism.


2013 ◽  
Vol 53 (A) ◽  
pp. 545-549 ◽  
Author(s):  
Aldo Morselli

Successfully launched in June 2008, the Fermi Gamma-ray Space Telescope, formerly named GLAST, has been observing the high-energy gamma-ray sky with unprecedented sensitivity in<br />the 20MeV ÷ 300 GeV energy range and electrons + positrons in the 7 GeV ÷ 1TeV range, opening a new observational window on a wide variety of astrophysical objects.


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