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’.

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.

URANIUM MEASUREMENT BY AIRBORNE GAMMA‐RAY SPECTROMETRY

Geophysics ◽  
1975 ◽  
Vol 40 (3) ◽  
pp. 503-519 ◽  
Author(s):  
R. L. Grasty
Keyword(s):  
Point Source ◽  
Gamma Ray ◽  
Radioactive Decay ◽  
High Energy ◽  
Gamma Ray Spectrometry ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Airborne Measurement ◽  
Decay Series ◽  
Different Depths

In the airborne measurement of uranium, window type gamma‐ray spectrometers are used and it is necessary to correct for scattered high energy radiation from thallium 208 in the thorium decay series. This radiation can be scattered in the crystal, in the ground, and in the air. A theory, analogous to the theory of radioactive decay, is developed; it can adequately explain the spectrum buildup in the uranium window for a point source of thorium oxide immersed to different depths in water and for a detector above the water. The theory is extended to predict the buildup as a function of altitude for detectors of different sizes and shows that errors in the airborne measurement of uranium can be, significant if no allowance is made for radiation scattered in the ground and in the air.

scholarly journals LECX: a cubesat experiment to detect and localize cosmic explosions in hard X-rays

2020 ◽  
Vol 493 (4) ◽  
pp. 4852-4860
Author(s):  
J Braga ◽  
O S C Durão ◽  
M Castro ◽  
F D’Amico ◽  
P E Stecchini ◽  
...  
Keyword(s):  
Gravitational Wave ◽  
Gamma Ray ◽  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Compact Objects ◽  
X Rays ◽  
X Ray ◽  
Competitive Capabilities ◽  
Cosmic Explosions

ABSTRACT With the advent of the nanosat/cubesat revolution, new opportunities have appeared to develop and launch small (∼1000 cm3), low-cost (∼US$ 1M) experiments in space in very short time frames (∼2  yr). In the field of high-energy astrophysics, in particular, it is a considerable challenge to design instruments with compelling science and competitive capabilities that can fit in very small satellite buses, such as a cubesat platform, and operate them with very limited resources. Here, we describe a hard X-ray (30–200 keV) experiment, LECX (‘Localizador de Explosões Cósmicas de Raios X’ – Locator of X-Ray Cosmic Explosions), that is capable of detecting and localizing within a few degrees events like gamma-ray bursts and other explosive phenomena in a 2U-cubesat platform, at a rate of ∼5 events per year. In the current gravitational wave era of astronomy, a constellation or swarm of small spacecraft carrying instruments such as LECX can be a very cost-effective way to search for electromagnetic counterparts of gravitational wave events produced by the coalescence of compact objects.

HIGH ENERGY RADIATION FROM GEMINGA (1E0630+178)

1993 ◽  
Vol 02 (04) ◽  
pp. 401-412
Author(s):  
PING-WAI KWOK
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
High Energy Radiation ◽  
Energy Radiation

Geminga is one of the brightest gamma-ray sources in the sky but its nature was a mystery for almost two decades. In this article we review the discovery of Geminga and the attempts to identify its nature as a radio-quiet pulsar. We will discuss some of the interpretations and implications.

scholarly journals Solar Flares: High-Energy Radiation and Particles

1989 ◽  
Vol 104 (1) ◽  
pp. 323-345 ◽  
Author(s):  
Erich Rieger
Keyword(s):  
Particle Acceleration ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Review Paper ◽  
Interplanetary Space ◽  
High Energy ◽  
Solar Disc ◽  
High Energy Radiation ◽  
Energy Radiation

AbstractDue to the Sun's proximity flares can be investigated in the gamma-ray regime and flare generated particles can be measured in space and related to particular events. In this review paper we focus on the problem of particle acceleration by using as observational ingredients: the fluxes and spectra of particles inferred from gamma-ray measurements and observed in interplanetary space, the temporal characteristics of flares at high-energy X- and gamma-rays and the distribution of gamma-ray flares over the solar disc.

Sign in / Sign up

Export Citation Format

Share Document