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相关论文: Time-Dependent Models for Blazar Emissions with th…

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Observations of blazar flaring states reveal remarkably different variability time scales. Especially rapid flares with flux doubling time scales of the order of minutes have been puzzling for quite some time. Many modeling attempts use the…

高能天体物理现象 · 物理学 2015-06-11 Michael Zacharias , Reinhard Schlickeiser

We perform time-dependent, spatially-resolved simulations of blazar emission to evaluate several flaring scenarios related to magnetic-field amplification and enhanced particle acceleration. The code explicitly accounts for…

Context. The origin of blazar variability, seen from radio up to gamma rays, is still a heavily debated matter and broadband flares offer a unique testbed towards a better understanding of these extreme objects. Such an energetic outburst…

The flat-spectrum radio quasar 3C~454.3 throughout the years has presented very high activity phases (flares) in which the different wavebands increase their flux dramatically. In this work, we perform multiwavelength analysis from radio to…

高能天体物理现象 · 物理学 2021-01-06 Raúl Antonio Amaya-Almazán , Vahram Chavushyan , Victor Manuel Patiño-Álvarez

Astrophysical models for the high-energy emission of blazars are reviewed. Blazars ejecting relativistic radio jets at small angles to the line-of-sight are the only type of active galactic nuclei (AGN) discovered above 100 MeV. The…

天体物理学 · 物理学 2007-05-23 Karl Mannheim

Detection of hard X-ray spectrum (spectral index < 2) from the kilo-parsec scale jet of active galactic nuclei cannot be accounted to the synchrotron emission mechanism from the electron distribution responsible for the radio/optical…

高能天体物理现象 · 物理学 2023-08-02 Amal A. Rahman , S. Sahayanathan , Malik Zahoor , P. A Subha

It is proposed that the spectra of so called 'MeV blazars' can be explained in terms of previously developed models of the external comptonization of accretion disk radiation provided that the structure of the inner and outer parts of the…

天体物理学 · 物理学 2020-11-25 W. Bednarek

It is well known that the flat radio spectrum is a common property in the spectral energy distribution of blazars. Although the one-zone leptonic models are generally successful in explaining the multi-wave band emission, they are…

高能天体物理现象 · 物理学 2021-06-02 Rui Xue , Ze-Rui Wang

Fermi Gamma ray Space Telescope measurements of spectra, variability time scale, and maximum photon energy give lower limits to the apparent jet powers and, through gammagamma opacity arguments, the bulk Lorentz factors of relativistic…

高能天体物理现象 · 物理学 2010-12-01 Charles D. Dermer , Soebur Razzaque

We present centimeter-band total flux density and linear polarization light curves illustrating the signature of shocks during radio band outbursts associated in time with gamma-ray flares detected by the Fermi LAT. The general…

高能天体物理现象 · 物理学 2011-11-01 M. F. Aller , P. A. Hughes , H. D. Aller , A. P. Marscher , S. G. Jorstad , T. Hovatta , M. C. Aller

We investigate the evolution of spectral energy distribution (SED) and underlying electron energy distribution (EED) by modeling the nearly simultaneous broadband spectra of selected bright 4FGL blazars, in the context of a combined cooling…

高能天体物理现象 · 物理学 2025-09-04 Muhammad S. Anjum , Shu-Jin Hou , Liang Chen , Zhigang Li , Minfeng Gu

Context. Blazars are among the most energetic objects in the Universe. In 2008 August, Fermi/LAT detected the blazar PKS 1502+106 showing a rapid and strong gamma-ray outburst followed by high and variable flux over the next months. This…

高能天体物理现象 · 物理学 2016-01-27 V. Karamanavis , L. Fuhrmann , T. P. Krichbaum , E. Angelakis , J. Hodgson , I. Nestoras , I. Myserlis , J. A. Zensus , A. Sievers , S. Ciprini

Sudden jets of collimated plasma arise from many locations on the Sun, including active regions. The magnetic field along which a jet emerges is often open to interplanetary space, offering a clear "escape route" for any flare-accelerated…

太阳与恒星天体物理 · 物理学 2018-11-07 Lindsay Glesener , Gregory D. Fleishman

Transition blazars exhibit a shift from one subclass to the next during different flux states. It is therefore crucial to study them to understand the underlying physics of blazars. We probe the origin of the multi-wavelength emission from…

高能天体物理现象 · 物理学 2023-11-17 Ashwani Pandey , Pankaj Kushwaha , Paul J. Wiita , Raj Prince , Bozena Czerny , C. S. Stalin

The emission of the so-called extreme blazars challenges the particle acceleration models. The hardness of its spectrum, $<2$, demands extreme parameters using the standard one-zone SSC model in the high energy band. Some authors use both…

高能天体物理现象 · 物理学 2021-08-27 E. Aguilar-Ruiz , N. Fraija

Blazars are an extreme subclass of active galactic nuclei. Their rapid variability, luminous brightness, superluminal motion, and high and variable polarization are probably due to a beaming effect. However, this beaming factor (or Doppler…

高能天体物理现象 · 物理学 2017-02-21 J. H. Fan , J. H. Yang , H. B. Xiao , C. Lin , D. Constantin , G. Y. Luo , Z. Y. Pei , J. M. Hao , Y. W. Mao

We reexamine stochastic Fermi acceleration (STFA) in the low energy (Newtonian) regime in the context of solar flares. The particle energization rate depends a dispersive term and a coherent gain term. The energy dependence of pitch angle…

天体物理学 · 物理学 2009-11-10 Robert Selkowitz , Eric G. Blackman

Using public \fermi LAT and \swift BAT observations, we constructed the first sample of blazars selected at both hard X-rays and gamma-rays. Studying its spectral properties, we find a luminosity dependence of the spectral slopes at both…

宇宙学与河外天体物理 · 物理学 2017-02-22 R. M. Sambruna , D. Donato , M. Ajello , L. Maraschi , the GSFC BAT Team

We extend our approach of modeling spectral energy distribution (SED) and lightcurves of blazars to include external Compton (EC) emission due to inverse Compton scattering of an external anisotropic target radiation field. We describe the…

高能天体物理现象 · 物理学 2015-06-19 Manasvita Joshi , Alan P. Marscher , Markus Boettcher