Extragalactic Background Light and energy spectra of Active Galactic Nuclei 3c454.3 and 1739+522 with high red shifts

2009 ◽  
Vol 196 ◽  
pp. 251-254
Author(s):  
V.G. Sinitsyna ◽  
A.A. Malyshko ◽  
F.I. Musin ◽  
S.I. Nikolsky ◽  
V.Y. Sinitsyna
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Energy Spectra ◽  
Extragalactic Background Light ◽  
Background Light

Chapter 3 Extra-galactic Gamma-Ray Sources

2021 ◽  
Author(s):  
Xiang-Yu Wang
Keyword(s):  
Active Galactic Nuclei ◽  
Lower Energy ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
Starburst Galaxies ◽  
Gamma Ray Bursts ◽  
Cherenkov Detector ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Water Cherenkov Detector

Abstract Extra-galactic gamma-ray sources, such as gamma-ray bursts, active galactic nuclei, starburst galaxies, are interesting and important targets for LHAASO observations. In this chapter, the prospects of detecting these sources with LHAASO and their physical implications are studied. The upgrade plan for the Water Cherenkov Detector Array (WCDA), which aims to enhance the detectability of relatively lower energy photons, is also presented. In addition, a study on constraining the extragalactic background light with LHAASO observation of blazars is presented.

High‐Energy Spectra of Active Galactic Nuclei. II. Absorption in Seyfert Galaxies

1997 ◽  
Vol 113 (2) ◽  
pp. 311-331 ◽  
Author(s):  
A. Malizia ◽  
L. Bassani ◽  
J. B. Stephen ◽  
G. Malaguti ◽  
G. G. C. Palumbo
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
High Energy ◽  
Energy Spectra

Perspective of detecting very high energy gamma-ray emission from active galactic nuclei with Large High Altitude Air Shower Observatory (LHAASO)

2016 ◽  
Vol 25 (01) ◽  
pp. 1650006 ◽  
Author(s):  
Yi Zhao ◽  
Qiang Yuan ◽  
Xiao-Jun Bi ◽  
Feng-Rong Zhu ◽  
Huan-Yu Jia
Keyword(s):  
High Altitude ◽  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Large Area ◽  
Extragalactic Background Light ◽  
Air Shower ◽  
Very High Energy ◽  
Very High

The detectability of active galactic nuclei (AGN), a major class of [Formula: see text]-ray emitters in the sky, by the newly planned Chinese project, Large High Altitude Air Shower Observatory (LHAASO), is investigated. The expectation is primarily based on the AGN catalog of Fermi Large Area Telescope (Fermi-LAT), with an extrapolation to the very high energy (VHE) range taking into account the absorption effect by the extragalactic background light (EBL). It is found that LHAASO may have the potential to detect more than several tens of the Fermi detected AGN, basically BL Lacertaes, with one-year sky survey. The capability of measuring the energy spectrum and light curve are also discussed.

scholarly journals EGRET High-Energy Gamma-ray Observations of AGN: Energy Spectra and Time Variability

1994 ◽  
Vol 159 ◽  
pp. 49-52 ◽  
Author(s):  
D.J. Thompson ◽  
D.L. Bertsch ◽  
B.L. Dingus ◽  
J. A. Esposito ◽  
C.E. Fichtel ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Energy Spectra ◽  
Time Variability ◽  
High Energy Gamma ◽  
Energy Gamma

The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory has detected more than 20 Active Galactic Nuclei (AGN) at photon energies above 30 MeV.

THE EXTRAGALACTIC BACKGROUND LIGHT: LOWER VERSUS UPPER LIMITS

2009 ◽  
Vol 18 (10) ◽  
pp. 1633-1637 ◽  
Author(s):  
MARTIN RAUE
Keyword(s):  
High Energy ◽  
Energy Spectra ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Upper Limits ◽  
Very High Energy ◽  
Γ Rays ◽  
Deep Source ◽  
Lower Limits ◽  
Very High

The discovery of distant sources of very high energy (VHE) γ-rays with hard energy spectra enabled to derive strong upper limits on the density of the extragalactic background light (EBL). These limits are close to the lower limits derived from deep source counts. A recent re-dertemination of the EBL contribution from resolved sources at 3.6 μm finds a higher EBL density, which is claimed to be in conflict with the assumptions utilized to derive the EBL upper limits from VHE spectra. Here, it is shown that is possible to recover the canonical Γ ~ 1.5 intrinsic spectra for such a higher EBL density.

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