VERY HIGH ENERGY GAMMA-RAY MEASUREMENTS OF BLAZARS

2008 ◽  
Vol 17 (09) ◽  
pp. 1431-1441
Author(s):  
BERRIE GIEBELS
Keyword(s):  
Black Hole ◽  
Gamma Ray ◽  
High Energy ◽  
The Status ◽  
Relativistic Flow ◽  
Very High Energy ◽  
Acceleration Zone ◽  
Energy Gamma ◽  
Γ Rays ◽  
Very High

The origin of γ-rays emitted by blazars is widely attributed to radiative cooling of the most energetic particles in a relativistic flow, which itself is thought to originate from the surroundings of a supermassive black hole. The linkage between the accreting gas, the black hole, jet formation, and the observed radiation from the jet, are still very difficult to establish. The most energetic γ-rays are likely to be produced close to the comptonizing particles acceleration zone, and are therefore a unique probe of the underlying physical mechanisms at play. This report contains a review of the status of the field of Very High Energy (VHE) γ-ray astronomy, in the light of measurements from the current generation of Atmospheric Čerenkov Telescopes (ACTs), which have dramatically changed our view of blazars over the last years, and given us new insights about the blazar phenomenon.

scholarly journals Very High Energy Gamma-Ray Radiation from the Stellar Mass Black Hole Binary Cygnus X-1

2007 ◽  
Vol 665 (1) ◽  
pp. L51-L54 ◽  
Author(s):  
J. Albert ◽  
E. Aliu ◽  
H. Anderhub ◽  
P. Antoranz ◽  
A. Armada ◽  
...  
Keyword(s):  
Black Hole ◽  
Gamma Ray ◽  
High Energy ◽  
Stellar Mass ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Black Hole Binary ◽  
Very High

scholarly journals Very high energy gamma-rays from flat spectrum radio quasars

2014 ◽  
Vol 10 (S313) ◽  
pp. 27-32
Author(s):  
Elina Lindfors
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
High Energy Gamma ◽  
Spectrum Radio ◽  
Very High Energy ◽  
Energy Gamma ◽  
Emission Models ◽  
Γ Rays ◽  
Very High

AbstractThe detection of Flat Spectrum Radio Quasars (FSRQs) in the Very High Energy (VHE, E>100 GeV) range is challenging, mainly because of their steep soft spectra and distance. Nevertheless four FSRQs are now known to be VHE emitters. The detection of the VHE γ-rays has challenged the emission models of these sources. The sources are also found to exhibit very different behavior. I will give an overview of what is known about the VHE emission of these sources and about the multiwavelength signatures that are connected to the VHE gamma-ray emission.

scholarly journals Detection of very-high-energy gamma-ray transients with monitoring facilities

2020 ◽  
Vol 497 (3) ◽  
pp. 3142-3148
Author(s):  
G La Mura ◽  
G Chiaro ◽  
R Conceição ◽  
A De Angelis ◽  
M Pimenta ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Field Of View ◽  
Telescope Array ◽  
Monitoring Strategies ◽  
Very High Energy ◽  
Energy Gamma ◽  
Γ Rays ◽  
Near Future ◽  
Very High

ABSTRACT The observation of very-high-energy γ-rays (VHE γ-rays, $E \gt 100\,$ GeV) has ledto the identification of extremely energetic processes and particle-acceleration sites both within our Galaxy and beyond. It is expected that VHE facilities, such as the Cherenkov Telescope Array, will explore these sources with an unprecedented level of detail. However, the transient and unpredictable nature of many important processes means that their observation requires the development of proper monitoring strategies. In this study, we estimate the properties of VHE transients that can be effectively detected by monitoring facilities. We use data collected by the Fermi-LAT instrument during its monitoring campaign to select events that are probably associated with VHE emission. We use this sample to estimate the frequency, the luminosity and the time-scales of various transients, focusing on blazar flares and gamma-ray bursts. We discuss how the balance between the field of view, sensitivity and duty cycle of an observatory affects the likelihood of detecting transients that occur at the inferred rates, and we conclude by describing the contribution that current and near-future monitoring facilities can make to the identification and study of VHE transient emission.

scholarly journals A STRONG RADIO BRIGHTENING AT THE JET BASE OF M 87 DURING THE ELEVATED VERY HIGH ENERGY GAMMA-RAY STATE IN 2012

2014 ◽  
Vol 788 (2) ◽  
pp. 165 ◽  
Author(s):  
K. Hada ◽  
M. Giroletti ◽  
M. Kino ◽  
G. Giovannini ◽  
F. D'Ammando ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Very High

scholarly journals Future science issues for Galactic very-high-energy gamma-ray astronomy

2008 ◽  
Author(s):  
Diego F. Torres ◽  
Felix A. Aharonian ◽  
Werner Hofmann ◽  
Frank Rieger
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Astronomy ◽  
High Energy Gamma ◽  
Future Science ◽  
Very High Energy ◽  
Energy Gamma ◽  
Very High
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