The Parsec-Scale Structure and Jet Motions of the TeV Blazars 1ES 1959+650, PKS 2155–304, and 1ES 2344+514
The Parsec-Scale Structure and Jet Motions of the TeV Blazars 1ES 1959+650, PKS 2155–304, and 1ES 2344+514
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DOI：
10.1086/379769
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发表时间：
2003-09
期刊：
影响因子：
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通讯作者：
B. Piner;Philip G. Edwards
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文献类型：
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作者：
B. Piner;Philip G. Edwards
作为TeV blazar喷流VLBI特性研究的一部分，我们在此提供了TeV blazar 1ES 1959 + 650、PKS 2155 - 304和1ES 2344 + 514的秒差距尺度喷流的一系列高分辨率15 GHz甚长基线阵列（VLBA）图像，线性分辨率约为0.5 pc。在1999年和2000年期间，VLBA在三个或四个时期观察到这些源中的每一个。在VLBI图像上明显缺乏任何强运动分量（与EGRET blazar中看到的快速超光速运动相反），VLBI喷流的结构可以被建模为一系列平稳的高斯分量或两个源（PKS 2155 - 304和1ES 2344 + 514）的平滑幂律。低的视速度，加上VLBI核心的亮温等波束指标，意味着VLBI射电辐射只有适度的多普勒增强，以及适度的体洛伦兹因子（δ和Γ a），与这些参数的更极端的值形成对比，这些参数被用来解释高能辐射。在秒差距尺度上没有看到移动的激波或等离子体团，这一事实表明，被认为是高能耀斑的原因的激波或等离子体团必须在VLBI图像上与核心分离之前消散。这就要求在秒差距尺度上损失大量的整体动能，并意味着比通常假设的内激波情况更高的效率。
As part of our study of the VLBI properties of TeV blazar jets, we present here a series of high-resolution 15 GHz Very Long Baseline Array (VLBA) images of the parsec-scale jets of the TeV blazars 1ES 1959+650, PKS 2155-304, and 1ES 2344+514, with linear resolutions of ~0.5 pc. Each of these sources was observed with the VLBA at three or four epochs during 1999 and 2000. There is a notable lack of any strong moving components on the VLBI images (in contrast to the rapid superluminal motions seen in EGRET blazars), and the structure of the VLBI jet can be modeled either as a series of stationary Gaussian components or as a smooth power law for two of the sources (PKS 2155-304 and 1ES 2344+514). The low apparent speeds, together with beaming indicators such as the brightness temperature of the VLBI core, imply only modest Doppler boosting of the VLBI radio emission and only modest bulk Lorentz factors (δ and Γ ≈ a few), in contrast to the more extreme values of these parameters invoked to explain the high-energy emission. The fact that no moving shocks or plasmoids are seen on the parsec scale suggests that the shocks or plasmoids that are assumed to be responsible for the high-energy flares must dissipate before they separate from the core on the VLBI images. This requires the loss of a substantial amount of bulk kinetic energy on parsec scales and implies a higher efficiency than is typically assumed for internal shock scenarios.