Japanese VLBI Network Observations of Radio-Loud Narrow-Line Seyfert 1 Galaxies
Japanese VLBI Network Observations of Radio-Loud Narrow-Line Seyfert 1 Galaxies
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DOI：
10.1093/pasj/59.4.703
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发表时间：
2007-04
影响因子：
2.3
通讯作者：
A. Doi;K. Fujisawa;M. Inoue;K. Wajima;H. Nagai;Keiichiro Harada;Kousuke Suematsu;A. Habe;
中科院分区：
文献类型：
--
作者：
A. Doi;K. Fujisawa;M. Inoue;K. Wajima;H. Nagai;Keiichiro Harada;Kousuke Suematsu;A. Habe;
利用日本VLBI网对5个射电强窄线Seyfert 1星系（NLS 1）进行了8.4 GHz的相位参考甚长基线干涉测量（VLBI）观测。在毫Jansky水平的五个目标（RXS J08066+7248、RXS J16290+4007、RXS J16333+4718、RXS J16446+2619和B3 1702+457）中的每一个都被检测到，并且在毫角秒分辨率下未被分辨，即，亮温高于10 7K。活动星系核活动的非热过程，而不是星爆，是主要负责从这些NLS 1的无线电发射。在九个已知的无线电噪声NLS 1中，包括本研究选择的那些，我们发现四个最大的无线电噪声对象都具有倒置光谱。这表明这些NLS 1可能是由于多普勒波束而产生的无线电噪声，这显然可以增强无线电功率和频谱频率。
We performed phase-reference very long baseline interferometry (VLBI) observations on five radio-loud narrow-line Seyfert 1 galaxies (NLS1s) at 8.4 GHz with the Japanese VLBI Network. Each of the five targets (RXS J08066+7248, RXS J16290+4007, RXS J16333+4718, RXS J16446+2619, and B3 1702+457) in milli-Jansky levels were detected and unresolved in milli-arcsecond resolutions, i.e., with brightness temperatures higher than 10 7 K. The nonthermal processes of active galactic nucleus activity, rather than starbursts, are predominantly responsible for the radio emissions from these NLS1s. Out of the nine known radio-loud NLS1s, including those chosen for this study, we found that the four most radio-loud objects exclusively have inverted spectra. This suggests a possibility that these NLS1s are radio-loud due to Doppler beaming, which can apparently enhance both the radio power and the spectral frequency.