scholarly journals The Properties of the Gamma-ray Bursts with High-energy Spectral Component

2015 ◽  
Vol 74 ◽  
pp. 287-291 ◽  
Author(s):  
I.V. Arkhangelskaja
Keyword(s):  
Gamma Ray ◽  
Spectral Component ◽  
High Energy ◽  
Gamma Ray Bursts

scholarly journals THE VERY BRIGHT AND NEARBY GRB130427A: THE EXTRA HARD SPECTRAL COMPONENT AND IMPLICATIONS FOR VERY HIGH-ENERGY GAMMA-RAY OBSERVATIONS OF GAMMA-RAY BURSTS

2014 ◽  
Vol 28 ◽  
pp. 1460174
Author(s):  
PAK-HIN THOMAS TAM
Keyword(s):  
Gamma Ray ◽  
Spectral Component ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Prompt Gamma ◽  
Large Area ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Very High

The extended high-energy gamma-ray (>100 MeV) emission occurring after the prompt gamma-ray bursts (GRBs) is usually characterized by a single power-law spectrum, which has been explained as the afterglow synchrotron radiation. We report on the Fermi Large Area Telescope (LAT) observations of the >100 MeV emission from the very bright and nearby GRB 130427A, up to ~100 GeV. By performing time-resolved spectral fits of GRB 130427A, we found a strong evidence of an extra hard spectral component above a few GeV that exists in the extended high-energy emission of this GRB. This extra spectral component may represent the first clear evidence of the long sought-after afterglow inverse Compton emission. Prospects for observations at the very high-energy gamma-rays, i.e., above 100 GeV, are described.

scholarly journals Gamma-ray Bursts at the Highest Energies

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 503
Author(s):  
Lara Nava
Keyword(s):  
Gamma Ray ◽  
Current Knowledge ◽  
Spectral Component ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Special Focus ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Very High Energy ◽  
Very High

Emission from Gamma-ray bursts is thought to be powered mainly by synchrotron radiation from energetic electrons. The same electrons might scatter these synchrotron seed photons to higher (>10 GeV) energies, building a distinct spectral component (synchrotron self-Compton, SSC). This process is expected to take place, but its relevance (e.g., the ratio between the SSC and synchrotron emitted power) is difficult to predict on the basis of current knowledge of physical conditions at GRB emission sites. Very high-energy radiation in GRBs can be produced also by other mechanisms, such as synchrotron itself (if PeV electrons are produced at the source), inverse Compton on external seed photons, and hadronic processes. Recently, after years of efforts, very high-energy radiation has been finally detected from at least four confirmed long GRBs by the Cherenkov telescopes H.E.S.S. and MAGIC. In all four cases, the emission has been recorded during the afterglow phase, well after the end of the prompt emission. In this work, I give an overview, accessible also to non-experts of the field, of the recent detections, theoretical implications, and future challenges, with a special focus on why very high-energy observations are relevant for our understanding of Gamma-ray bursts and which long-standing questions can be finally answered with the help of these observations.

scholarly journals CONSTRAINING THE HIGH-ENERGY EMISSION FROM GAMMA-RAY BURSTS WITHFERMI

2012 ◽  
Vol 754 (2) ◽  
pp. 121 ◽  
Author(s):  
◽  
M. Ackermann ◽  
M. Ajello ◽  
L. Baldini ◽  
G. Barbiellini ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Energy Emission ◽  
High Energy Emission

scholarly journals Upper limits on the high-energy emission from gamma-ray bursts observed by AGILE-GRID

2012 ◽  
Vol 547 ◽  
pp. A95 ◽  
Author(s):  
F. Longo ◽  
E. Moretti ◽  
L. Nava ◽  
R. Desiante ◽  
M. Olivo ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Energy Emission ◽  
Upper Limits ◽  
High Energy Emission

Observations of high-energy gamma-ray bursts with EGRET

1995 ◽  
pp. 358-362 ◽  
Author(s):  
M. Merck ◽  
D. L. Bertsch ◽  
B. L. Dingus ◽  
C. E. Fichtel ◽  
R. C. Hartman ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
High Energy Gamma ◽  
Energy Gamma

On detection of high-energy neutrinos from sources of gamma-ray bursts

1995 ◽  
Vol 231 (1-2) ◽  
pp. 339-341 ◽  
Author(s):  
M. Ostrowski ◽  
A. A. Zdziarski
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
High Energy Neutrinos

The Search for High Energy Extended Emission by Fermi-LAT from Swift-localized Gamma-ray Bursts

2011 ◽  
Author(s):  
J. Chiang ◽  
J. L. Racusin ◽  
J. E. McEnery ◽  
J. L. Racusin ◽  
N. Gehrels ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Extended Emission
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