Long-term Multiband Study of High-redshift Blazar S5 0836 71
Long-term Multiband Study of High-redshift Blazar S5 0836 71
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高红移 Blazar S5 0836 71 的长期多波段研究
DOI：
10.1088/1538-3873/aaeae6
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发表时间：
2019
影响因子：
3.5
通讯作者：
Zeng Wei
中科院分区：
文献类型：
--
作者：
Yang Jianping;Yang Chuyuan;Zhou Bing;Zeng Wei
我们分析了10年来对高红移耀变体S5 0836+ 71（z= 2.172）的费米γ射线观测，该观测显示2015年发生了强烈的耀斑，其特征是γ射线通量在几天内增加了几倍。γ射线和R波段（AZT-8）之间的离散相关函数显示，γ射线变化领先R波段约75天，具有高度显著（> 99.9%置信度）的相关性。采用同步辐射自康普顿加外康普顿（EC）模型模拟了光谱能量分布，讨论了高通量态和低通量态之间跃迁的原因。在耀斑前和耀斑状态下，EC种子光子可能主要来自尘埃环而不是宽线区（BLR）的再处理发射。这意味着辐射斑点的位置在BLR之外和尘埃环面之内。从耀斑前状态到耀斑状态，δ和B减小，而N 0和γ max相应增大。模拟结果表明，发射电子总数的增加和发射电子功率谱的硬化是γ射线耀斑的主要原因。
We analyze 10 years of Fermi γ-ray observations of the high-redshift blazar S5 0836+ 71 (z= 2.172) that showed a strong flare in 2015 characterized by a several-fold increase in the γ-ray flux within a few days. The discrete correlation function between the γ-ray and the R band (AZT-8) shows a highly significant (> 99.9% confidence) correlation with the γ-ray variations leading the R band by about 75 days. The spectral energy distributions are modeled, with the adoption of a synchrotron self-Compton plus external Compton (EC) model, to discuss the reasons of transition between the low-and high-flux states. In both the pre-flare and flare states, the EC seed photons might be dominated by reprocessed emission from the dusty torus rather than the broadline region (BLR). This implies the location of radiating blob outside the BLR and inside the dusty torus. From the pre-flare state to the flare state, δ and B decrease, whereas N 0 and γ max increase accordingly. The results of the modeling suggest that the increase in the total number of emitting electrons and hardening of the power spectrum of emitting electrons are primary causes of the flare in γ-rays.