Turbulence and magnetic fields in elliptical galaxies
Turbulence and magnetic fields in elliptical galaxies
复制标题
椭圆星系中的湍流和磁场
DOI：
10.1093/mnras/279.1.229
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发表时间：
1996
影响因子：
4.8
通讯作者：
A. Shukurov
中科院分区：
文献类型：
--
作者：
D. Moss;A. Shukurov
讨论了椭圆星系X射线晕中湍流和星际磁场的物理本质。湍流速度场由两个分量表示，由I型超新星驱动的声学湍流和以恒星相对于星际气体的运动为能量源的涡旋湍流。声波湍流的典型速度为60 km S-1，尺度为350 pc。对于旋涡湍流，这分别是3 km S-1和3 pc;后者的速度场预计是相当不均匀的。湍流运动驱动发电机产生，在10千秒差距的银河中心距离内，随机磁场的强度约为14 J！G在中心，并减少到1 J！在半径10千秒差距的G;相关尺度是相同的声学湍流，即几百秒差距。磁场产生的空间波动的法拉第旋转措施，其幅度为30和300 rad m- 2，观测线性分辨率为1千秒差距和0.1千秒差距，分别。
We discuss the physical nature of turbulence and interstellar magnetic fields in the X-ray haloes of elliptical galaxies. The turbulent velocity field is represented by two components, acoustic turbulence driven by type I supernovae and vortical turbulence whose energy source is the stellar motion with respect to the interstellar gas. The typical velocity of the sound-wave turbulence is 60 km S-1 and the scale is 350 pc. For the vortical turbulence, these are 3 km S-1 and 3 pc, respectively; the latter velocity field is expected to be rather inhomogeneous. The turbulent motions drive a dynamo generating, within a galactocentric distance of 10 kpc, random magnetic fields whose strength is about 14 J!G at the centre and decreases to 1 J!G at radius 10 kpc; the correlation scale is the same as that of the acoustic turbulence, i.e. a few hundred parsecs. The magnetic fields produce spatial fluctuations in the Faraday rotation measure whose amplitude is 30 and 300 rad m- 2, for observations with linear resolution 1 kpc and 0.1 kpc, respectively.