The Interface between the Outer Heliosphere and the Inner Local ISM: Morphology of the Local Interstellar Cloud, Its Hydrogen Hole, Str;mgren Shells, and 60Fe Accretion** Based on observations made with the NASA/ESA Hubble Space Telescope obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS AR-09525.01A. These observations are associated with programs #12475, 12596.
The Interface between the Outer Heliosphere and the Inner Local ISM: Morphology of the Local Interstellar Cloud, Its Hydrogen Hole, Str;mgren Shells, and 60Fe Accretion** Based on observations made with the NASA/ESA Hubble Space Telescope obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS AR-09525.01A. These observations are associated with programs #12475, 12596.
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DOI：
10.3847/1538-4357/ab498a
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发表时间：
2019-11-20
影响因子：
4.9
通讯作者：
Tilipman, Dennis
中科院分区：
文献类型：
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作者：
Linsky, Jeffrey L.;Redfield, Seth;Tilipman, Dennis
我们描述了外部日光层和围绕太阳的星际介质(LISM)之间的界面。内部LISM的组成部分是与外日光层接触的四个部分电离的云(本地星际云(LIC)、G云、蓝云和Aql云)，以及主要来自？；CMA的EUV辐射产生的电离气体。基于62个视线的星际吸收，我们构造了LIC的三维形状，结果表明，在？；CMA，？；CMA，和天狼星；B方向，LIC中心开始的中性氢柱密度最小。我们称这个区域为氢洞。在这个方向上，蓝云吸收的存在和LIC吸收的缺乏可以简单地用位于日光层外的蓝云来解释。我们认为蓝云的外缘是一个在H；II区高压驱动下朝向日光层的应力壳层。我们发现流经日光层的中性和电离氦的矢量与LIC流矢量不一致，附近的云间气体与？；CMA和其他恒星源的电离是一致的，不需要额外的电离源或百万度等离子体。在迎风方向，日光层正在穿过几个LISM云的环境，这可能解释了最近从南极雪地测量到的超新星喷发出的含有Fe-60的星际颗粒的涌入。
We describe the interface between the outer heliosphere and the local interstellar medium (LISM) surrounding the Sun. The components of the inner LISM are the four partially ionized clouds (the Local Interstellar Cloud (LIC), G cloud, Blue cloud, and Aql cloud) that are in contact with the outer heliosphere, and ionized gas produced by EUV radiation primarily from ?;CMa. We construct the three-dimensional shape of the LIC based on interstellar line absorption along 62 sightlines and show that in the directions of ?;CMa, ?;CMa, and Sirius;B the neutral hydrogen column density from the center of the LIC is a minimum. We call this region the ?hydrogen hole.? In this direction, the presence of Blue cloud absorption and the absence of LIC absorption can be simply explained by the Blue cloud lying just outside the heliosphere. We propose that the outer edge of the Blue cloud is a Str;mgren shell driven toward the heliosphere by high pressures in the H;ii region. We find that the vectors of neutral and ionized helium flowing through the heliosphere are inconsistent with the LIC flow vector, and that the nearby intercloud gas is consistent with ionization by ?;CMa and other stellar sources without requiring additional sources of ionization or million-degree plasma. In the upwind direction, the heliosphere is passing through an environment of several LISM clouds, which may explain the recent influx of interstellar grains containing Fe-60 from supernova ejecta measured in Antarctic snow.