scholarly journals Doppler Boosting Effect on the Jet Radiation of Gamma-Ray Bursts and Active Galactic Nuclei

2016 ◽  
Vol 12 (S324) ◽  
pp. 82-84
Author(s):  
Xiao-Li Huang ◽  
Hai-Ming Zhang ◽  
Shu-Qing Zhong ◽  
En-Wei Liang

AbstractHigh energy photon radiations of gamma-ray bursts (GRBs) and active galactic nuclei (AGNs) are dominated by their jet radiations. It was suggested that relativistic jets powered by different mass-scale black holes may share the same physical laws. A tight relation among the peak luminosity, the peak photon energy in the νfν spectrum, and the initial Lorentz factor is found for GRBs. With samples of GeV-TeV BL Lacs, FSRQs, and NLS1 galaxies, we show that these sources do not follow this relation. This may be attributed to the jet geometry and continuous/episodic jet as well as radiation physics for different kinds of sources.

2016 ◽  
Vol 12 (S324) ◽  
pp. 11-18
Author(s):  
Elina Lindfors

AbstractActive galactic nuclei, hosting supermassive black holes and launching relativistic jets, are the most numerous objects on the gamma-ray sky. At the other end of the mass scale, phenomena related to stellar mass black holes, in particular gamma-ray bursts and microquasars, are also seen on the gamma-ray sky. While all of them are thought to launch relativistic jets, the diversity even within each of these classes is enormous. In this review, I will discuss recent very high energy gamma-ray results that underline both the similarity of the black hole systems, as well as their diversity.


Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Yoshiyuki Inoue ◽  
Dmitry Khangulyan ◽  
Akihiro Doi

To explain the X-ray spectra of active galactic nuclei (AGN), non-thermal activity in AGN coronae such as pair cascade models has been extensively discussed in the past literature. Although X-ray and gamma-ray observations in the 1990s disfavored such pair cascade models, recent millimeter-wave observations of nearby Seyferts have established the existence of weak non-thermal coronal activity. In addition, the IceCube collaboration reported NGC 1068, a nearby Seyfert, as the hottest spot in their 10 yr survey. These pieces of evidence are enough to investigate the non-thermal perspective of AGN coronae in depth again. This article summarizes our current observational understanding of AGN coronae and describes how AGN coronae generate high-energy particles. We also provide ways to test the AGN corona model with radio, X-ray, MeV gamma ray, and high-energy neutrino observations.


2013 ◽  
Vol 9 (S298) ◽  
pp. 427-427
Author(s):  
Jinzhong Liu ◽  
Yu Zhang ◽  
Guojie Feng ◽  
Chunhai Bai

AbstractA one-meter wide field astronomical telescope with Alt-Az mount, putting in work at prime focus with field corrector, is located at the Nanshan site of Xinjiang Astronomical Observatory. The Nanshan One meter Wide-field Telescope (hereafter NOWT) provides excellent optical quality, pointing accuracy and tracking accuracy. The main scientific goals of NOWT are supernovae, gamma-ray bursts, novae, variable stars, and active galactic nuclei. It is worthwhile to point out that the sky background at the Nanshan is a classic optical site.


2021 ◽  
Vol 2021 (01) ◽  
pp. 038-038
Author(s):  
Wei Zhu ◽  
Zechun Zheng ◽  
Peng Liu ◽  
Lihong Wan ◽  
Jianhong Ruan ◽  
...  

2021 ◽  
Author(s):  
Xiang-Yu Wang

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.


2003 ◽  
Vol 214 ◽  
pp. 331-332
Author(s):  
Zhuo Li ◽  
Z. G. Dai ◽  
T. Lu

Gamma-ray bursts (GRBs) are believed to originate from ultra-relativistic fireballs, with initial Lorentz factor η ∼ 102 − 103. However very high energy photons may still suffer from γγ interaction. We show here that in a wide range of model parameters, the resulting pairs may dominate electrons associated with the fireball baryons. This may provide an explanation for the rarity of prompt optical detections. A rapid response to the GRB trigger at the IR band would detect such a strong flash.


2019 ◽  
Vol 207 ◽  
pp. 03001 ◽  
Author(s):  
Ludwig Rauch

The IceCube neutrino observatory has discovered a flux of extragalactic neutrinos. However, the origin of these neutrinos is still unknown. Among the possible candidates are Gamma-Ray Bursts (GRBs), Core-Collapse Supernovae (SNe), Active Galactic Nuclei (AGN) and Tidal Disruption Events (TDEs) - all are accompanied by a characteristic optical counterpart. The goal of this study is thus to identify the neutrino sources by detecting their optical counterparts with the Zwicky Transient Facility (ZTF). ZTF features a high cadence northern-sky survey enabling realtime correlation of optical transients with high-energy neutrino candidates. In this talk I will highlight the multimessenger potential of ZTF for an online neutrino correlation study with Ice- Cube.


2013 ◽  
Vol 774 (1) ◽  
pp. L5 ◽  
Author(s):  
Jin Zhang ◽  
En-Wei Liang ◽  
Xiao-Na Sun ◽  
Bing Zhang ◽  
Ye Lu ◽  
...  

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