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arXiv 1310.7853astro-ph.SR
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用AIA/SDO观测盘上冕洞中喷流的动力学行为

The dynamical behaviour of a jet in an on-disk coronal hole observed with AIA/SDO

K. Chandrashekhar, R. J. Morton, D. Banerjee, G. R. Gupta

摘要:

位于冕洞中的极紫外射流被认为在向日冕和太阳风提供加热物质方面起着重要作用。SDO上的多波长能力和高信噪比探测器允许对这些喷流的演化进行详细研究。我们的目标是利用SDO的能力,揭示射流动力学的信息,并获得与射流相关的等离子体特性的估计。本文研究了冕洞边界AIA/SDO极紫外喷流的动力学性质。详细讨论了射流演化过程,并测量了射流的参数,如长度、宽度、寿命、向外速度等。此外,利用自动排放测量分析来确定射流的温度和密度的估计。还观察到由射流尖顶支撑的传播横波。波的特性的测量被用于磁震学,并与发射测量结果一起用于估计射流的磁场强度。我们提出了一个详细的描述射流的演变,与新的证据等离子体流,在射流的启动之前,沿环路在射流的基础上,还发现进一步的证据表明,沿射流尖顶流包括多个,准周期性的小规模等离子体喷射事件。此外,DEM分析表明,喷流的温度为$\log{5.89\pm0.08}$ K,电子密度为$\log{8.75\pm0.05}$ cm $^{-3}$。横波的测量特性表明,当它以$\sim110$ km/s的速度沿喷流尖顶传播时,横波被严重阻尼。波参数的磁震反演提供了沿喷流尖顶的$B=1.21\pm0.2$ G值,这与以前对冕洞中开放场的估计一致。

英文摘要:

EUV jets situated in coronal holes are thought to play an important role in supplying heated material to the corona and solar wind. The multi-wavelength capabilities and high signal-to-noise of detectors on-board SDO allows for detailed study of these jet's evolution. We aim to exploit SDO's capabilities to reveal information on the jet dynamics and obtain estimates for plasma properties associated with the jet. We study the dynamics an EUV jet with AIA/SDO at a coronal hole boundary. The details of the jet evolution are discussed and measurements of the jet's parameters, e.g. length, width, life time, outward speed, are obtained. Further, automated emission measure analysis is exploited to determine estimates for the temperature and density of the jet. A propagating transverse wave supported by the jet spire is also observed. Measurement of the wave properties are exploited for magneto-seismology and are used in conjunction with the emission measure results to estimate the magnetic field strength of the jet. We present a detailed description of the jet's evolution, with new evidence for plasma flows, prior to the jet's initiation, along the loops at the base of the jet and also find further evidence that flows along the jet spire consist of multiple, quasi-periodic small-scale plasma ejection events. In addition, DEM analysis suggests that the jet has temperatures of $\log{5.89\pm0.08}$ K and electron densities of $\log{8.75\pm0.05}$ cm$^{-3}$. Measured properties of the transverse wave suggest the wave is heavily damped as it propagates along the jet spire with speeds of $\sim110$ km/s. The magneto-seismological inversion of the wave parameters provides values of $B=1.21\pm0.2$ G along the jet spire, which is in line with previous estimates for open fields in coronal holes.}

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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