VLBI Observations of the Most Radio-Loud, Narrow-Line Quasar SDSS J094857.3 + 002225
VLBI Observations of the Most Radio-Loud, Narrow-Line Quasar SDSS J094857.3 + 002225
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DOI：
10.1093/pasj/58.5.829
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发表时间：
2006-08
影响因子：
2.3
通讯作者：
A. Doi;H. Nagai;K. Asada;S. Kameno;K. Wajima;M. Inoue
中科院分区：
文献类型：
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作者：
A. Doi;H. Nagai;K. Asada;S. Kameno;K. Wajima;M. Inoue
我们利用甚长基线阵（VLBA）在1.7-15.4GHz波段观测了窄线类星体SDSS J094857.3+002225，它是箭线Seyfert 1星系（NLS 1 s）中射电能量最高的一个。这是第一个甚长基线干涉测量（VLBI）的无线电响亮NLS调查1。我们独立地发现了（1）非常高的亮度温度，从它的紧凑性在VLBA图像和（2）通量变化之间的VLBA观测和我们的其他观测与VLBA和甚大阵列（VLA）。多普勒因子大于2.7-5.5，以满足在静止帧的亮度温度的固有限制。这是NLS 1中高度相对论性非热喷流的证据。我们认为多普勒因子是决定NLS 1射电响度的重要参数之一。SDSS J094857.3+002225的吸积盘可能处于非常高的状态，而不是高/软状态，这与具有强烈射电爆发和超光速喷流的X射线双星（如GRS 1915+105）类似。
We observed the narrow-line quasar SDSS J094857.3+002225, which is known to have the highest radio loudnessin thenarrow-line Seyfert 1 galaxies(NLS1s), at 1.7–15.4GHz withthe VeryLong BaselineArray (VLBA). This is the first very-long-baseline interferometry (VLBI) investigation of a radio-loud NLS1. We independently discovered (1) very high brightness temperatures from its compactness in a VLBA image and (2) flux variation among the VLBA observation and our other observations with the VLBA and the Very Large Array (VLA). A Doppler factor larger than 2.7–5.5 was required to meet an intrinsic limit of brightness temperature in the rest frame. This is evidence for highly relativistic nonthermal jets in an NLS1. We suggest that the Doppler factor is one of the most important parameters in the determination of the radio loudness of NLS1s. The accretion disk of SDSS J094857.3+002225 is probably in a very high state, rather than the high/soft state, by analogy with X-ray binaries with strong radio outbursts and superluminal jets, such as GRS 1915+105.