Evidence for Solar-Wind Charge-Exchange X-Ray Emission from the Earth's Magnetosheath(Chapter 4. Warm and Hot IntraGalactic Medium, The Extreme Universe in the Suzaku Era)
Evidence for Solar-Wind Charge-Exchange X-Ray Emission from the Earth's Magnetosheath(Chapter 4. Warm and Hot IntraGalactic Medium, The Extreme Universe in the Suzaku Era)
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DOI：
10.1143/ptps.169.71
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发表时间：
2006-09
影响因子：
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通讯作者：
R. Fujimoto;K. Mitsuda;D. McCammon;Y. Takei;M. Bauer;Y. Ishisaki;F. Scott Porter;H. Yamaguchi;K. Hayashida;N. Yamasaki
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文献类型：
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作者：
R. Fujimoto;K. Mitsuda;D. McCammon;Y. Takei;M. Bauer;Y. Ishisaki;F. Scott Porter;H. Yamaguchi;K. Hayashida;N. Yamasaki
我们报告了2005年9月2日在朱竹北黄道极观测的长期增强（LTE）中，在459eV明显探测到cvi 4p到1s的过渡线。观测到的谱线强度与367eV的cvi 2p ~ 1s谱线强度相当。这是电荷交换过程的有力证据。此外，ovii、oviii、nex、a和MgXI系也有明显的增强。在750-900eV范围内也有一些特征，可能是由于Fe L线，O VIII的高阶跃迁（3p到1s和6p到1s）和Ne IX线的一些组合。从x射线强度与太阳风通量在大约半天的时间尺度上的相关性以及x射线强度的短期（~ 10分钟）变化来看，这些谱线很可能是由太阳风重离子与地球磁鞘中的中性物质相互作用引起的。硬幂律成分也是解释LTE频谱所必需的。它的起源尚不清楚。我们的结果表明，太阳活动可以显著污染Suzaku宇宙x射线光谱低于1keV。提出了在扩大污染源观测中识别这类污染的建议。
We report an apparent detection of the C VI 4p to 1s transition line at 459eV, during a long-term enhancement (LTE) in the Suzaku north ecliptic pole observation of 2005 September 2. The observed line intensity is comparable to that of the C VI 2p to 1s line at 367eV. This is strong evidence for the charge-exchange process. In addition, O VII, O VIII ,N eX ,a nd MgXI lines showed clear enhancements. There are also features in the 750–900eV range that could be due to some combination of Fe L lines, higher order transitions of O VIII (3p to 1s and 6p to 1s), and a Ne IX line. From the correlation of the X-ray intensity with the solar-wind flux on time scales of about half a day, and from the short-term (∼ 10minutes) variations of the X-ray intensity, these lines most likely arise from solar-wind heavy ions interacting with neutral material in the Earth’s magnetosheath. A hard power-law component is also necessary to explain the LTE spectrum. Its origin is not yet known. Our results indicate that solar activity can significantly contaminate Suzaku cosmic X-ray spectra below ∼ 1keV. Recommendations are provided for recognizing such contamination in observations of extended sources.