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arXiv 0804.2440astro-ph
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太阳风电荷交换X射线发射局域气泡模型的修正

Revising the Local Bubble Model due to Solar Wind Charge Exchange X-ray Emission

Robin L. Shelton

摘要:

通过对太阳附近热局域磁泡软X射线辐射的观测,对热局域磁泡进行了初步研究。通过将所有观察到的局部软X射线归因于气泡来获得测量结果。然而,越来越多的证据表明,日光层也会产生漫射X射线。其来源是太阳风离子,这些离子从另一个原子接收了一个电子。这种对局部产生的漫射X射线的另一种解释的存在,使人们对局部气泡的存在和性质提出了质疑。本文将讨论这些问题。它回顾了太阳风电荷交换(SWCX)X射线生产的文献,发现SWCX约占在低纬度地区观察到的本地1/4 keV X射线的一半。本文还对日球OVI柱密度和强度进行了预测,发现它们小于观测误差。继续相信局部气泡包含热气体的证据包括剩余的局部1/4 keV强度,观察到的局部O VI柱密度,以及用某种等离子体填充局部区域的需要。如果真正的局域气泡的亮度只有我们之前所认为的一半,那么它的电子密度和热压力是我们之前所认为的1/2,它的能量需求和发射量是我们之前所认为的1/2。这些调整可以很容易地适应,事实上,使局部气泡的压力与相邻材料的压力更加一致。对今后的工作提出了建议。

英文摘要:

The hot Local Bubble surrounding the solar neighborhood has been primarily studied through observations of its soft X-ray emission. The measurements were obtained by attributing all of the observed local soft X-rays to the bubble. However, mounting evidence shows that the heliosphere also produces diffuse X-rays. The source is solar wind ions that have received an electron from another atom. The presence of this alternate explanation for locally produced diffuse X-rays calls into question the existence and character of the Local Bubble. This article addresses these questions. It reviews the literature on solar wind charge exchange (SWCX) X-ray production, finding that SWCX accounts for roughly half of the observed local 1/4 keV X-rays found at low latitudes. This article also makes predictions for the heliospheric O VI column density and intensity, finding them to be smaller than the observational error bars. Evidence for the continued belief that the Local Bubble contains hot gas includes the remaining local 1/4 keV intensity, the observed local O VI column density, and the need to fill the local region with some sort of plasma. If the true Local Bubble is half as bright as previously thought, then its electron density and thermal pressure are 1/square-root(2) as great as previously thought, and its energy requirements and emission measure are 1/2 as great as previously thought. These adjustments can be accommodated easily, and, in fact, bring the Local Bubble's pressure more in line with that of the adjacent material. Suggestions for future work are made.

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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