arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0902.0011astro-ph.GAastro-ph.CO
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湍流介质的视线统计方法:发射和吸收线的VCS

Line-of-sight statistical methods for turbulent medium: VCS for emission and absorption lines

D. Pogosyan, A. Lazarian

摘要:

我们提出了一个概述的速度坐标谱(速度坐标谱),一种新的技术,用于研究天体物理湍流,利用多普勒展宽谱线的视线统计。我们认为检索的湍流光谱从发射强度观测的高和低的空间分辨率,并发现,即使当发射湍流体积不空间分辨的湍流允许一个研究。这为使用该技术进行河外研究开辟了有趣的前景。如果使用光学深度而不是强度,则针对光谱发射线开发的方法也适用于吸收线。点源光谱中吸收线的消除得益于有效的窄波束,并且不需要通过采样方向来密集天空覆盖。即使是强饱和的吸收线仍然携带着关于小尺度湍流的信息,尽管仅限于线的翅膀。结合不同的吸收线,人们可以开发出星际气体中湍流的复杂性断层摄影。

英文摘要:

We present an overview of the Velocity Coordinate Spectrum (VCS), a new technique for studying astrophysical turbulence that utilizes the line-of-sight statistics of Doppler-broadened spectral lines. We consider the retrieval of turbulence spectra from emission intensity observations of both high and low spatial resolution and find that the VCS allows one to study turbulence even when the emitting turbulent volume is not spatially resolved. This opens interesting prospects for using the technique for extragalactic research. VCS developed for spectral emission lines is applicable to absorption lines as well if the optical depth is used instead of intensity. VCS for absorption lines in point-source spectra benefit from effectively narrow beam and does not require dense sky coverage by sampling directions. Even strongly saturated absorption lines still carry the information about the small scale turbulence, albeit limited to the wings of a line. Combining different absorption lines one can develop tomography of the turbulence in the interstellar gas in all its complexity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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