• X. Zhang

      Articles written in Journal of Astrophysics and Astronomy

    • Multi-Wavelength Variability in PKS 2155-304

      Y. G. Zheng L. Zhang X. Zhang H. J. Ma

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      We study multi-wavelength variability in BL Lacertae object PKS 2155-304 in the frame of the time dependent one-zone synchrotron self-Compton (SSC) model, where stochastic particle acceleration is taken into account. In this model, a homogeneously and isotropically spherical structure is assumed, the Fokker–Planck type equation which describes the evolution of the particles energy is numerically solved, and the synchrotron and self-Compton components from the spherical blob are calculated. Our results can reproduce observed spectra energy distribution (SED) and give definite predictions for the flux and spectral variability of PKS 2155-304.We find that particle injection rate, magnetic field and Doppler factor in the acceleration zone are important parameters for explaining its flaring behaviour.

    • 𝛾-Rays Radiation of High Redshift Fermi Blazars

      W. G. Liu S. H. Fu X. Zhang L. Ma Y. B. Li D. R. Xiong

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      Based on the 31 high redshift (𝑧 > 2) Flat Spectral Radio Quasars (FSRQs), which is from the second Fermi-LAT AGNs catalogue (2LAC), we studied the correlation between flux densities (𝐹R, 𝐹K, 𝐹𝛾) in the radio, infrared and 𝛾-ray wave bands. We found that there is a significant positive correlation between 𝐹𝛾 and 𝐹R, and a weak anticorrelation between 𝐹𝛾 and 𝐹K in the average state. For high redshift blazars, we argue that the seed photon of 𝛾-ray emission mainly comes from the jet itself and partially from the dusty torus.

    • Spectral Energy Distributions of XBLs, RBLs and FSRQs

      Y. Y. Bao L. E. Chen H. Z. Li Z. Y. Peng X. Zhang

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      We have collected a sample of 86 blazars and analysed the redshift 𝑧, the accretion rate 4$\dot{m}$ and the spectral index of the sample.

  • Journal of Astrophysics and Astronomy | News

    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

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