scholarly journals VERY HIGH-ENERGY NEUTRINOS FROM SLOWLY DECAYING, MASSIVE DARK MATTER AS A SOURCE OF EXPLOSIVE ENERGY FOR GAMMA-RAY BURSTS

2003 ◽  
Vol 18 (07) ◽  
pp. 477-489
Author(s):  
SAUL BARSHAY ◽  
GEORG KREYERHOFF
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Dense Matter ◽  
High Energy ◽  
Wide Distribution ◽  
Gamma Ray Bursts ◽  
Moderate Degree ◽  
X Rays ◽  
Very High Energy ◽  
Total Energies

We consider a speculative model for gamma-ray bursts (GRB), which predicts that the total kinetic energy in the ejected matter is less than the total energy in the gamma rays. There is also secondary energy in X-rays, which are emitted contemporaneously with the gamma rays. The model suggests that bremsstrahlung and Compton up-scattering by very energetic electrons, are important processes for producing the observed burst radiation. The dynamics naturally allows for the possibility of a moderate degree of beaming of matter and radiation in some gamma-ray bursts. GRB are predicted to have an intrinsically wide distribution in total energies, in particular, on the low side. They are predicted to occur at large redshifts, z ~ 8, in local regions of dense matter.

Very high-energy gamma rays from gamma-ray bursts

2007 ◽  
Vol 365 (1854) ◽  
pp. 1343-1356 ◽  
Author(s):  
Paula M Chadwick
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Gamma Ray Burst ◽  
Gamma Ray Astronomy ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Very High

Very high-energy (VHE) gamma-ray astronomy has undergone a transformation in the last few years, with telescopes of unprecedented sensitivity having greatly expanded the source catalogue. Such progress makes the detection of a gamma-ray burst at the highest energies much more likely than previously. This paper describes the facilities currently operating and their chances for detecting gamma-ray bursts, and reviews predictions for VHE gamma-ray emission from gamma-ray bursts. Results to date are summarized.

scholarly journals e±-rich GRB Fireball and Infrared Flashes

2003 ◽  
Vol 214 ◽  
pp. 331-332
Author(s):  
Zhuo Li ◽  
Z. G. Dai ◽  
T. Lu
Keyword(s):  
Gamma Ray ◽  
Lorentz Factor ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Rapid Response ◽  
Model Parameters ◽  
Wide Range ◽  
Very High Energy ◽  
Very High

Gamma-ray bursts (GRBs) are believed to originate from ultra-relativistic fireballs, with initial Lorentz factor η ∼ 102 − 103. However very high energy photons may still suffer from γγ interaction. We show here that in a wide range of model parameters, the resulting pairs may dominate electrons associated with the fireball baryons. This may provide an explanation for the rarity of prompt optical detections. A rapid response to the GRB trigger at the IR band would detect such a strong flash.

scholarly journals Very High Energy Gamma Rays from Plerions: CANGAROO Results

1998 ◽  
Vol 188 ◽  
pp. 125-128
Author(s):  
T. Kifune
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
Current Status ◽  
Emission Region ◽  
Thermal Processes ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Very High

The current status of very high energy gamma ray astronomy (in ~ 1 TeV region) is described by using as example results of CANGAROO (Collaboration of Australia and Nippon for a GAmma Ray Observatory in the Outback). Gamma rays at TeV energies, emitted through inverse Compton effect of electrons or π0 decay from proton interaction, provide direct evidence on “hot” non-thermal processes of the Universe, as well as environmental features, such as the strength of magnetic field in the emission region, for the non-thermal processes.

scholarly journals Physical Constraints on Models of Gamma-Ray Bursters

1986 ◽  
Vol 89 ◽  
pp. 305-321
Author(s):  
Richard I. Epstein
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
Burst Source ◽  
Gamma Ray Burst ◽  
Physical Constraints ◽  
Low Energies ◽  
Energy Gamma ◽  
Photon Interactions

AbstractThe power per logarithmic bandwidth in gamma-ray burst spectra generally increases rapidly with energy through the x-ray range and does not cut off sharply above a few MeV. This spectral form indicates that a very small fraction of the energy from a gamma-ray burst source is emitted at low energies or is reprocessed into x-rays and that the high-energy gamma rays are not destroyed by photon-photon interactions. The implications are that the emission mechanism for the gamma-ray bursts is not synchrotron radiation from electrons that lose most of their energy before being re-accelerated and that either the regions from which the gamma rays are emitted are large compared to the size of a neutron star or the emission is collimated and beamed away from the stellar surface.

scholarly journals The Flare of 1989 September 9, 09:09 UT: Does Coronal Loop Collision Initiate Efficient Gamma-Ray Emission?

1994 ◽  
Vol 142 ◽  
pp. 707-711
Author(s):  
H. Aurass ◽  
A. Hofmann ◽  
E. Rieger
Keyword(s):  
Current Sheet ◽  
Gamma Rays ◽  
Coronal Loop ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
Subject Headings ◽  
Γ Ray ◽  
Gamma Ray Emission ◽  
Magnetogram Data

AbstractVector magnetogram data and Hα pictures together with data published by Chupp et al. lead us to conjecture that in the presented case a contact between the rising two-ribbon flare current sheet and a coronal loop connecting two nearby plage regions initiates efficient high-energy γ-ray emission.Subject headings: Sun: corona — Sun: flares — Sun: X-rays, gamma rays

scholarly journals GAMMA RAY BURSTS AND PARTICLE PHYSICS

1995 ◽  
Vol 10 (38) ◽  
pp. 2897-2913
Author(s):  
DAVID B. CLINE
Keyword(s):  
Black Hole ◽  
Particle Physics ◽  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Primordial Black Hole ◽  
Black Hole Evaporation ◽  
Very High Energy ◽  
Fine Time ◽  
Made In

We provide a brief review of the current situation concerning gamma ray bursts, with emphasis on the role that particle physics may play in the interesting phenomena. The current understanding of GRB origins allows for a large range of physical processes from primordial black hole evaporation to neutron star and black hole collisions. There does not seem to be a simple standard luminosity function and the burst times range from ms to 1000 s of seconds five orders of magnitude. It is likely that some type of fireball model is needed to explain the GRBs. No counterparts of GRB have been detected. We indicate some ways in which progress can be made in either the study of the fine time structure (~μs) or the detection of very high energy photons (>100 GeV to >100 TeV). We also indicate how a small but unique class of the GRB could come from primordial black hole evaporation.

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