• Si-Le He

      Articles written in Journal of Astrophysics and Astronomy

    • Ratio of the Core to the Extended Emissions in the Comoving Frame for Blazars

      Yun-Tian Li Shao-Yu Fu Huan-Jian Feng Si-Le He Chao Lin Jun-Hui Fan Denise Costantin Yu-Tao Zhang

      More Details Abstract Fulltext PDF

      In a two-component jet model, the emissions are the sum of the core and extended emissions: $S^{\mathrm{ob}}=S_{\mathrm{core}}^{\mathrm{ob}}+S_{\mathrm{ext}}^{\mathrm{ob}}$, with the core emissions, $S_{\mathrm{core}}^{\mathrm{ob}}= f S_{\mathrm{ext}}^{\mathrm{ob}}\delta ^{q}$ being a function of the Doppler factor $\delta$, the extended emission $S_{\mathrm{ext}}^{\mathrm{ob}}$, the jet type dependent factor q, and the ratio of the core to the extended emissions in the comoving frame, f. The f is an unobservable but important parameter. Following our previous work, we collect 65 blazars with available Doppler factor $\delta$, superluminal velocity $\beta _{\mathrm{app}}$, and core-dominance parameter, R, and calculated the ratio, f, and performed statistical analyses. We found that the ratio, f, in BL Lacs is on average larger than that in FSRQs. We suggest that the difference of the ratio f between FSRQs and BL Lacs is one of the possible reasons that cause the difference of other observed properties between them. We also find some significant correlations between $\log f$ and other parameters, including intrinsic (de-beamed) peak frequency, $\log \nu _{\mathrm{p}}^{\mathrm{in}}$, intrinsic polarization, $\log P^{\mathrm{in}}$, and core-dominance parameter, $\log R$, for the whole sample. In addition, we show that the ratio, f, can be estimated by R.

  • 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.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.