The hard X-ray to low-energy gamma-ray spectrum of the Crab Nebula

1989 ◽  
Vol 338 ◽  
pp. 972 ◽  
Author(s):  
G. V. Jung
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
Low Energy ◽  
X Ray ◽  
Energy Gamma ◽  
The Crab Nebula

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 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.

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.

scholarly journals Constraints on the late X-ray radiation from the low-energy gamma-ray burst of December 3, 2003: INTEGRAL data

2006 ◽  
Vol 32 (5) ◽  
pp. 297-301 ◽  
Author(s):  
S. Yu. Sazonov ◽  
A. A. Lutovinov ◽  
E. M. Churazov ◽  
R. A. Sunyaev
Keyword(s):  
Gamma Ray ◽  
Low Energy ◽  
Gamma Ray Burst ◽  
X Ray ◽  
Energy Gamma ◽  
Integral Data

scholarly journals Time-Domain Astronomy with Swift, Fermi and Lobster

2011 ◽  
Vol 7 (S285) ◽  
pp. 41-46 ◽  
Author(s):  
Neil Gehrels ◽  
Scott D. Barthelmy ◽  
John K. Cannizzo
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
Tidal Disruption ◽  
X Ray ◽  
Order Of Magnitude ◽  
New Type ◽  
The Crab Nebula ◽  
High Energy Emission ◽  
Higher Sensitivity

AbstractThe dynamic transient gamma-ray sky is revealing many interesting results, largely due to findings by Fermi and Swift. The list includes new twists on gamma-ray bursts (GRBs), a GeV flare from a symbiotic star, GeV flares from the Crab Nebula, high-energy emission from novae and supernovae, and, within the last year, a new type of object discovered by Swift—a jetted tidal disruption event. In this review we present highlights of these exciting discoveries. A new mission concept called Lobster is also described; it would monitor the X-ray sky at order-of-magnitude higher sensitivity than current missions can.

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

Low-energy cosmic X-ray measurements

1969 ◽  
Vol 47 (23) ◽  
pp. 2651-2666 ◽  
Author(s):  
A. J. Baxter ◽  
B. G. Wilson ◽  
D. W. Green
Keyword(s):  
Spectral Analysis ◽  
Energy Range ◽  
Crab Nebula ◽  
Spectral Characteristics ◽  
Low Energy ◽  
Data Recovery ◽  
X Rays ◽  
X Ray ◽  
Recovery System ◽  
The Crab Nebula

An experiment is described to investigate cosmic X rays in the energy range 0.25–12 keV. The data-recovery system and methods of spectral analysis are considered. Results are presented for the energy spectrum of the diffuse X-ray component and its distribution over the northern sky down to 1.6 keV with a limited extension at 0.27 keV.In the energy range 1.6 to 12 keV, the spectrum is represented by:[Formula: see text]although separate analyses indicate a flattening below 4.5 keV to give:[Formula: see text]and[Formula: see text]At the lowest energies, the flux appears to increase more rapidly and exhibits some anisotropy in arrival directions related to the gross galactic structure. Spectral characteristics of the Crab Nebula and Cygnus X-2 have also been determined.

Cadmium telluride for low energy gamma-ray and X-ray spectrometers

1972 ◽  
Vol 98 (3) ◽  
pp. 597-598 ◽  
Author(s):  
J.M. Palms ◽  
R.E. Wood ◽  
O.H. Puckett ◽  
K. Zanio
Keyword(s):  
Cadmium Telluride ◽  
Gamma Ray ◽  
Low Energy ◽  
X Ray ◽  
Energy Gamma
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