Observation of transient high-energy emission features in the spectra of black hole candidates and the Crab Nebula by Granat/SIGMA

1994 ◽  
Vol 92 ◽  
pp. 411 ◽  
Author(s):  
M. Gilfanov ◽  
E. Churazov ◽  
R. Sunyaev ◽  
N. Khavenson ◽  
B. Novikov ◽  
...  
Keyword(s):  
Black Hole ◽  
Crab Nebula ◽  
High Energy ◽  
Energy Emission ◽  
The Crab Nebula ◽  
High Energy Emission ◽  
Black Hole Candidates

scholarly journals Time-Domain Astronomy with Swift, Fermi and Lobster

2011 ◽  
Vol 7 (S285) ◽  
pp. 41-46 ◽  
Author(s):  
Neil Gehrels ◽  
Scott D. Barthelmy ◽  
John K. Cannizzo
Keyword(s):  
Gamma Ray ◽  
Crab Nebula ◽  
High Energy ◽  
Tidal Disruption ◽  
X Ray ◽  
Order Of Magnitude ◽  
New Type ◽  
The Crab Nebula ◽  
High Energy Emission ◽  
Higher Sensitivity

AbstractThe dynamic transient gamma-ray sky is revealing many interesting results, largely due to findings by Fermi and Swift. The list includes new twists on gamma-ray bursts (GRBs), a GeV flare from a symbiotic star, GeV flares from the Crab Nebula, high-energy emission from novae and supernovae, and, within the last year, a new type of object discovered by Swift—a jetted tidal disruption event. In this review we present highlights of these exciting discoveries. A new mission concept called Lobster is also described; it would monitor the X-ray sky at order-of-magnitude higher sensitivity than current missions can.

scholarly journals HIGH-ENERGY EMISSION FROM JET–CLOUD INTERACTIONS IN AGNs

2010 ◽  
Vol 19 (06) ◽  
pp. 931-936 ◽  
Author(s):  
ANABELLA T. ARAUDO ◽  
VALENTÍ BOSCH-RAMON ◽  
GUSTAVO E. ROMERO
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Line Emission ◽  
Galactic Nuclei ◽  
Small Region ◽  
High Energy ◽  
Energy Emission ◽  
Central Regions ◽  
High Energy Emission

Active galactic nuclei present continuum and line emission. The emission lines are originated by gas located close to the central supermassive black hole. Some of these lines are broad, and would be produced in a small region called broad-line region. This region could be formed by clouds surrounding the central black hole. In this work, we study the interaction of such clouds with the base of the jets in active galactic nuclei, and we compute the produced high-energy emission. We focus on sources with low luminosities in the inner jet regions, to avoid strong gamma-ray absorption. We find that the resulting high-energy radiation may be significant in Centaurus A. Also, this phenomenon might be behind the variable gamma-ray emission detected in M87, if very large dark clouds are present. The detection of jet–cloud interactions in active galactic nuclei would give information on the properties of the jet base and the very central regions.

TeV observations of the Galactic center and starburst galaxies

2013 ◽  
Vol 9 (S303) ◽  
pp. 29-42
Author(s):  
Mathieu de Naurois
Keyword(s):  
Black Hole ◽  
Cosmic Rays ◽  
Galactic Center ◽  
High Energy ◽  
Starburst Galaxies ◽  
Energy Emission ◽  
Very High Energy ◽  
Sgr A ◽  
High Energy Emission ◽  
Very High

AbstractThe vicinity of the Galactic center harbors many potential accelerators of cosmic rays (CR) that could shine in very-high-energy (VHE) γ-rays, such as pulsar wind nebulae, supernova remnants, binary systems and the central black hole Sgr A*, and is characterized by high gas density, large magnetic fields and a high rate of starburst activity similar to that observed in the core of starburst galaxies. In addition to these astrophysical sources, annihilation of putative WIMPs concentrated in the gravitational well could lead to significant high-energy emission at the Galactic center. The Galactic center region has been observed by atmospheric Cherenkov telescopes, and in particular by the H. E. S. S. array in Namibia for the last ten years above 150 GeV. This large data set, comprising more than 200 hours of observations, led to the discovery of a point-like source spatially compatible with the supermassive black hole Sgr A*, and to an extended diffuse emission, correlated with molecular clouds and attributed to the interaction of cosmic rays with the interstellar medium. Over the same time period, two starburst galaxies, namely M 82 and NGC 253, were detected at TeV energies after very deep exposures. Results from these ten years of observations of the Galactic center region and starburst galaxies at TeV energies are presented, and implications for the various very-high-energy emission mechanisms are discussed.

scholarly journals The connection between radio and high energy emission in black hole powered systems in the SKA era

2015 ◽  
Author(s):  
Marcello Giroletti ◽  
Monica Orienti ◽  
Filippo D'Ammando ◽  
Francesco Massaro ◽  
Gino Tosti ◽  
...  
Keyword(s):  
Black Hole ◽  
High Energy ◽  
Energy Emission ◽  
High Energy Emission

High‐Energy Emission from the TeV Blazar Markarian 501 during Multiwavelength Observations in 1996

1999 ◽  
Vol 514 (1) ◽  
pp. 138-147 ◽  
Author(s):  
J. Kataoka ◽  
J. R. Mattox ◽  
J. Quinn ◽  
H. Kubo ◽  
F. Makino ◽  
...  
Keyword(s):  
High Energy ◽  
Energy Emission ◽  
High Energy Emission ◽  
Multiwavelength Observations

scholarly journals HIGH-ENERGY EMISSION OF GRB 130427A: EVIDENCE FOR INVERSE COMPTON RADIATION

2013 ◽  
Vol 776 (2) ◽  
pp. 95 ◽  
Author(s):  
Yi-Zhong Fan ◽  
P. H. T. Tam ◽  
Fu-Wen Zhang ◽  
Yun-Feng Liang ◽  
Hao-Ning He ◽  
...  
Keyword(s):  
High Energy ◽  
Energy Emission ◽  
Inverse Compton ◽  
High Energy Emission
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