A low-energy gamma-ray observation of the Crab Nebula

1977 ◽  
Vol 212 ◽  
pp. 704 ◽  
Author(s):  
P. Mandrou ◽  
M. Niel ◽  
G. Vedrenne ◽  
A. Dupont
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
Low Energy ◽  
Energy Gamma ◽  
The Crab Nebula

scholarly journals Gamma-Ray Spectrometry of Galactic Sources in the Energy Range 0.2–3.0 MeV

1971 ◽  
Vol 41 ◽  
pp. 45-57 ◽  
Author(s):  
A Bui-Van ◽  
G. Vedrenne ◽  
P. Mandrou
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Signal To Noise Ratio ◽  
Crab Nebula ◽  
Low Energy ◽  
Gamma Ray Spectrometry ◽  
Angular Aperture ◽  
Energy Gamma ◽  
Galactic Sources ◽  
The Crab Nebula

A low energy gamma-ray telescope (0.2–3 MeV) has been studied in our laboratory. It is made up of an active honeycomb collimator of Nai(T1), with a geometrical angular aperture of 1.5°, and of a detector composed of 73 Nai(T1) sticks (0.5 cm diam.–5 cm length) incorporated in a plastic gabarit used in anticoincidence.The directivity of the telescope is obtained at low energy by the collimator, and at higher energy by the directivity which exists in the gamma-ray interaction through the Compton and photoelectric effects. The electrons emitted in these interactions which are not contained in the sticks of Nai(T1) are detected by the plastic anticoincidence scintillator. Only laboratory tests are presented here, for the study of the galactic gamma-rays, however, the system must subsequently be protected by a 4 cm thick anticoincidence well. In fact the detector directivity enables a great increase in the signal to noise ratio to be expected without greatly increasing the thickness of the shielding.According to the results obtained the estimation of the minimum exposure time for the ‘Crab Nebula’ would be about 2h30m to have a signal at 1 MeV with 2σ of confidence above the background.

Measurements of low-energy gamma radiation from the Crab Nebula and from pulsar NP 0532

1975 ◽  
Vol 202 ◽  
pp. 502 ◽  
Author(s):  
G. D. Walraven ◽  
R. D. Hall ◽  
C. A. Meegan ◽  
P. L. Coleman ◽  
D. H. Shelton ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Crab Nebula ◽  
Low Energy ◽  
Energy Gamma ◽  
The Crab Nebula

scholarly journals High‐Energy Gamma‐Ray Observations of the Crab Nebula and Pulsar with the Solar Tower Atmospheric Cerenkov Effect Experiment

2001 ◽  
Vol 547 (2) ◽  
pp. 949-958 ◽  
Author(s):  
S. Oser ◽  
D. Bhattacharya ◽  
L. M. Boone ◽  
M. C. Chantell ◽  
Z. Conner ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
High Energy Gamma ◽  
Energy Gamma ◽  
The Crab Nebula ◽  
Cerenkov Effect ◽  
Effect Experiment

scholarly journals Impact of H.E.S.S. Lidar profiles on Crab Nebula data

2019 ◽  
Vol 197 ◽  
pp. 01001 ◽  
Author(s):  
Justine Devin ◽  
Johan Bregeon ◽  
Georges Vasileiadis ◽  
Yves Gallant
Keyword(s):  
Energy Range ◽  
Photon Energy ◽  
Gamma Ray ◽  
Crab Nebula ◽  
Systematic Errors ◽  
High Energy ◽  
Atmospheric Composition ◽  
Direct Impact ◽  
Energy Gamma ◽  
The Crab Nebula

The H.E.S.S. experiment in Namibia is a high-energy gamma-ray telescope sensitive in the energy range from 30 GeV to a several tens of TeV, that uses the atmospheric Cherenkov technique to detect showers developed within the atmosphere. The elastic lidar, installed on the H.E.S.S. site, allows to reduce the systematic errors related to the atmospheric composition uncertainties thanks to the estimation of the extinction profile for the Cherenkov light (300-650 nm). The latter has a direct impact on the reconstructed parameters, such as the photon energy and the source flux. In this paper we report on physics results obtained on the Crab Nebula spectrum using the lidar profiles obtained at the H.E.S.S. site.

scholarly journals The Crab Pulsar and Nebula as Seen in Gamma-Rays

Universe ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 448
Author(s):  
Elena Amato ◽  
Barbara Olmi
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
Crab Pulsar ◽  
Gamma Ray Astronomy ◽  
Very High Energy ◽  
Energy Gamma ◽  
The Crab Nebula ◽  
The Impact ◽  
Very High

Slightly more than 30 years ago, Whipple detection of the Crab Nebula was the start of Very High Energy gamma-ray astronomy. Since then, gamma-ray observations of this source have continued to provide new surprises and challenges to theories, with the detection of fast variability, pulsed emission up to unexpectedly high energy, and the very recent detection of photons with energy exceeding 1 PeV. In this article, we review the impact of gamma-ray observations on our understanding of this extraordinary accelerator.

The ultra-high energy gamma-ray burst from the Crab Nebula observed by the Baksan EAS array

1992 ◽  
Vol 18 (4) ◽  
pp. L83-L88 ◽  
Author(s):  
V V Alexeenko ◽  
Y M Andreyev ◽  
A E Chudakov ◽  
Y S Elensky ◽  
A S Lidvansky ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
Ultra High Energy ◽  
Gamma Ray Burst ◽  
High Energy Gamma ◽  
Energy Gamma ◽  
The Crab Nebula

A Search for Ultra–High‐Energy Gamma‐Ray Emission from the Crab Nebula and Pulsar

1997 ◽  
Vol 481 (1) ◽  
pp. 313-326 ◽  
Author(s):  
A. Borione ◽  
M. A. Catanese ◽  
M. C. Chantell ◽  
C. E. Covault ◽  
J. W. Cronin ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Gamma ◽  
Energy Gamma ◽  
Gamma Ray Emission ◽  
The Crab Nebula

scholarly journals Synchrotron Radiation in High Magnetic Fields

1971 ◽  
Vol 46 ◽  
pp. 314-320
Author(s):  
D. F. Falla ◽  
A. Evans
Keyword(s):  
Synchrotron Radiation ◽  
Magnetic Fields ◽  
Gamma Ray ◽  
Radiation Power ◽  
Crab Nebula ◽  
Low Energy ◽  
High Magnetic Fields ◽  
X Ray ◽  
The Crab Nebula ◽  
Fundamental Mechanism

We suggest that if there exist within the Crab Nebula localised condensations of material containing high magnetic fields, (≫ 1 G), the rapidly evolving synchrotron radiation power spectrum emitted by a single electron can give a radiation continuum with a spectral index having a unique value similar to that observed in the optical and low-energy X-ray regions. One implication of this result is that a simple comparison between the observed fluxes of optical and gamma radiation emitted by the Nebula is no longer meaningful, so that one cannot draw any immediate conclusion regarding the fundamental mechanism of electron and gamma ray production.

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