Dual-Frequency VSOP Imaging of the Jet in S5 0836+710
Dual-Frequency VSOP Imaging of the Jet in S5 0836+710
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DOI：
10.1093/pasj/58.2.253
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发表时间：
2005-07
影响因子：
2.3
通讯作者：
P. Astron;Soc;Japan.;A. Lobanov;T. Krichbaum;A. Witzel;J. Zensus
中科院分区：
文献类型：
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作者：
P. Astron;Soc;Japan.;A. Lobanov;T. Krichbaum;A. Witzel;J. Zensus
发光高红移（z =2）。17) 1997年10月，用1.6GHz和5GHz的VSOP观测到类星体S5 0836+710。我们在这里报告了一张以前未发表的1.6GHz数据图像，并比较了这颗类星体在两个频率下的相对论性喷流的结构。我们提供了一个光谱指数图像，追踪了距离原子核40毫弧秒的射流的光谱特性。图像中观测到的弯曲射流脊线和光谱指数分布可以用马赫数为~ 6的相对论性流出中出现的开尔文-亥姆霍兹不稳定性来描述。在这个描述中，射流的整体脊线是由开尔文-亥姆霍兹不稳定性的螺旋表面模式形成的，而嵌入流中的平坦光谱指数区域对应于不稳定性的椭圆表面模式产生的压力增强。目前还不能排除涉及一系列缓慢消散的冲击的另一种解释。
The luminous high-redshift (z =2 .17) quasar S5 0836+710 was observed in 1997 October with the VSOP at 1.6GHz and 5GHz. We report here a previously unpublished image made from the data at 1.6GHz, and compare the structure of a relativistic jet in this quasar at two frequencies. We present a spectral index image tracing the spectral properties of the jet up to ∼ 40 milliarcsec distance from the nucleus. The curved jet ridge line observed in the images and the spectral index distribution can be described by a Kelvin–Helmholtz instability developing in a relativistic outflow with a Mach number of ∼ 6. In this description, the overall ridge line of the jet is formed by the helical surface mode of the Kelvin–Helmholtz instability, while areas of flatter spectral index embedded into the flow correspond to pressure enhancements produced by the elliptical surface mode of the instability. An alternative explanation involving a sequence of slowly dissipating shocks cannot be ruled out at this point.