VLBI Observations of Gamma-Ray-quiet Active Galactic Nuclei: Comparing Radio-Core Brightness Temperatures
VLBI Observations of Gamma-Ray-quiet Active Galactic Nuclei: Comparing Radio-Core Brightness Temperatures
复制标题
伽马射线安静活动星系核的 VLBI 观测：比较射电核心亮度温度
DOI：
10.1086/305494
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
J. Quick
中科院分区：
文献类型：
--
作者：
S. Tingay;D. Murphy;J. Lovell;M. Costa;P. McCulloch;P. Edwards;D. Jauncey;J. Reynolds;A. Tzioumis;E. King;D. Jones;R. Preston;D. Meier;T. V. van Ommen;G. Nicolson;J. Quick
我们目前VLBI和澳大利亚望远镜紧凑阵列图像和推导源帧无线电核心亮度温度为三个突出的，平谱河外射电源，值得注意的是，因为他们还没有被检测到的伽马射线源EGRET仪器。无线电核心的亮度温度进行了讨论，作为相对论光束的指标。EGRET识别和伽马射线安静，无线电大声AGN的源帧无线电核心亮度温度的比较表明，很大范围内的聚束特性可能存在，独立的伽马射线发射水平。这种比较表明，虽然在EGRET确认的活动星系核中，射电辐射和伽马射线辐射之间有很强的关系，而且许多EGRET确认的活动星系核显示出相对论性聚束的证据，但几乎没有证据表明伽马射线辐射的强度和射电辐射聚束的程度之间存在一一对应的关系。
We present VLBI and Australia Telescope Compact Array images and derive source-frame radio-core brightness temperatures for three prominent, flat-spectrum extragalactic radio sources, notable because they have not been detected as gamma-ray sources with the EGRET instrument. Radio-core brightness temperatures are discussed as an indicator of relativistic beaming. A comparison of source-frame radio-core brightness temperatures for EGRET-identified and gamma-ray-quiet, radio-loud AGNs shows that a wide range in beaming properties is likely to exist, independent of the level of gamma-ray emission. This comparison suggests that, although there is a strong relationship between radio emission and gamma-ray emission in EGRET-identified AGNs, and many EGRET-identified AGNs show evidence for relativistic beaming, there is little evidence for a one-to-one correspondence between the strength of gamma-ray emission and the degree of beaming of the radio emission.