Probing the Radio Counterpart of Gamma-ray Flaring Region in 3C 84
Probing the Radio Counterpart of Gamma-ray Flaring Region in 3C 84
复制标题
探测 3C 84 中伽马射线耀斑区域的射电对应体
DOI：
10.1051/epjconf/20136104008
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
K.
中科院分区：
文献类型：
--
作者：
Nagai;H.;Orienti;M.;Kino;M.;Doi;A.;Giovannini;G.;Asada;K.;D'Ammando;F.;Haga;T.;Giroletti;M.;Hada;K.
与射电/巨椭圆星系NGC 1275有关的射电源3C 84是探测γ射线发射区射电对应物的最佳目标之一。虽然这个源在γ射线波段显示出明显的时间变化，但在γ射线变化的时间尺度上没有发现射电光变曲线的明显相关性。γ射线耀斑区的位置一直是一个悬而未决的问题。在这篇文章中，我们首先回顾了我们以前的射电观测结果。接下来，我们将根据43 GHz的甚长基线阵列（VLBA）数据展示我们的新结果。我们发现了与2005年射电爆发相关的“重启”喷流中的边缘增亮结构。在1990年代，喷流结构是脊增亮而不是边缘增亮，尽管观测是在类似的角分辨率下进行的。这表明射电喷流的横向结构形态最近确实发生了变化。这种形态的变化与γ射线通量密度的时间变化表现出有趣的一致性，即，90年代的γ通量密度比现在低7倍多。我们讨论了从脊增亮到临边增亮的转变与γ射线时间变率有关的可能性。
The radio source 3C 84 associated with the radio/giant elliptical galaxy NGC 1275 is one of the best targets to probe the radio counterpart of theγ-ray emitting region. Although this source shows clear time variability inγ-ray bands, no clear correlation in radio light curve was found on the timescale of –ray variability. The location of theγ-ray flaring region has been an open question. In this proceeding, we firstly review our previous findings from radio observations. Next we present our new results based on the Very Long Baseline Array (VLBA) data at 43 GHz. We discover the limb-brightened structure in the “restarted” jet associated with the 2005 radio outburst. In 1990s, the jet structure was rather ridge-brightening than limbbrightening, despite the observations were done with similar angular resolution. This indicates that the radio jet morphology in terms of the transverse structure has been indeed changed recently. This change in the morphology shows an interesting agreement with the time variation of theγ-ray flux density, i.e., theγ-ray flux density in 1990s was more than 7 times lower than the current one. We argue the possibility that the transition from ridge-brightening to limb-brightening is related to theγ-ray time variability.