scholarly journals Search for ultra-high energy radiation from gamma-ray bursts

1994 ◽  
Vol 426 ◽  
pp. L1 ◽  
Author(s):  
D. E. Alexandreas ◽  
G. E. Allen ◽  
D. Berley ◽  
S. Biller ◽  
R. L. Burman ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Ultra High Energy ◽  
High Energy Radiation ◽  
Energy Radiation

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 High-energy astrophysics and the search for sources of gravitational waves

2018 ◽  
Vol 376 (2120) ◽  
pp. 20170294 ◽  
Author(s):  
P. T. O'Brien ◽  
P. Evans
Keyword(s):  
Gravitational Wave ◽  
Short Duration ◽  
Gamma Ray ◽  
New Technology ◽  
High Energy ◽  
Compact Objects ◽  
Wide Field ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Binary Mergers

The dawn of the gravitational-wave (GW) era has sparked a greatly renewed interest into possible links between sources of high-energy radiation and GWs. The most luminous high-energy sources—gamma-ray bursts (GRBs)—have long been considered as very likely sources of GWs, particularly from short-duration GRBs, which are thought to originate from the merger of two compact objects such as binary neutron stars and a neutron star–black hole binary. In this paper, we discuss: (i) the high-energy emission from short-duration GRBs; (ii) what other sources of high-energy radiation may be observed from binary mergers; and (iii) how searches for high-energy electromagnetic counterparts to GW events are performed with current space facilities. While current high-energy facilities, such as Swift and Fermi, play a crucial role in the search for electromagnetic counterparts, new space missions will greatly enhance our capabilities for joint observations. We discuss why such facilities, which incorporate new technology that enables very wide-field X-ray imaging, are required if we are to truly exploit the multi-messenger era. This article is part of a discussion meeting issue ‘The promises of gravitational-wave astronomy’.

Daily search for emission of ultra-high-energy radiation from point sources

1993 ◽  
Vol 405 ◽  
pp. 353 ◽  
Author(s):  
D. E. Alexandreas ◽  
G. Allen ◽  
D. Berley ◽  
S. Biller ◽  
R. L. Burman ◽  
...  
Keyword(s):  
High Energy ◽  
Point Sources ◽  
Ultra High Energy ◽  
High Energy Radiation ◽  
Energy Radiation
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