| Item type |
会議発表論文 / Conference Paper(1) |
| 公開日 |
2015-03-26 |
| タイトル |
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タイトル |
Stellar-wind drag force on dust aggregates around young main-sequence stars |
|
言語 |
en |
| 言語 |
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|
言語 |
eng |
| キーワード |
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主題Scheme |
Other |
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主題 |
恒星風 |
| キーワード |
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主題Scheme |
Other |
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主題 |
ちり集合体 |
| キーワード |
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主題Scheme |
Other |
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主題 |
恒星フォトン |
| キーワード |
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主題Scheme |
Other |
|
主題 |
主系列星 |
| キーワード |
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主題Scheme |
Other |
|
主題 |
摩擦抗力 |
| キーワード |
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主題Scheme |
Other |
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主題 |
運動量輸送 |
| キーワード |
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主題Scheme |
Other |
|
主題 |
角運動量 |
| キーワード |
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主題Scheme |
Other |
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主題 |
放射圧 |
| キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
stellar wind |
| キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
dust aggregate |
| キーワード |
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言語 |
en |
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主題Scheme |
Other |
|
主題 |
stellar photon |
| キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
main sequence star |
| キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
friction drag |
| キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
momentum transfer |
| キーワード |
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言語 |
en |
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主題Scheme |
Other |
|
主題 |
angular momentum |
| キーワード |
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|
言語 |
en |
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主題Scheme |
Other |
|
主題 |
radiation pressure |
| 資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_5794 |
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資源タイプ |
conference paper |
| アクセス権 |
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アクセス権 |
metadata only access |
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アクセス権URI |
http://purl.org/coar/access_right/c_14cb |
| 著者 |
山本, 哲生
湊, 哲則
Kohler, Melanie
木村, 宏
Mann, Ingrid
Yamamoto, Tetsuo
Minato, Tetsunori
Kohler, Melanie
Kimura, Hiroshi
Mann, Ingrid
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| 著者所属 |
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北海道大学低温科学研究所 |
| 著者所属 |
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Westfalische Wilhelms Universitat Institut fur Planetologie |
| 著者所属 |
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Westfalische Wilhelms Universitat Institut fur Planetologie |
| 著者所属 |
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北海道大学低温科学研究所 |
| 著者所属 |
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Westfalische Wilhelms Universitat Institut fur Planetologie |
| 著者所属（英） |
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en |
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Institute of Low Temperature Science, Hokkaido University |
| 著者所属（英） |
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en |
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Westfalische Wilhelms Universitat Institut fur Planetologie |
| 著者所属（英） |
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en |
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Westfalische Wilhelms Universitat Institut fur Planetologie |
| 著者所属（英） |
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en |
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Institute of Low Temperature Science, Hokkaido University |
| 著者所属（英） |
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en |
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Westfalische Wilhelms Universitat Institut fur Planetologie |
| 出版者 |
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出版者 |
宇宙航空研究開発機構宇宙科学研究本部 |
| 出版者（英） |
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出版者 |
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS) |
| 書誌情報 |
第38回月・惑星シンポジウム
en : Proceedings of the 38th ISAS Lunar and Planetary Symposium
p. 122-122,
発行日 2006-03
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| 抄録（英） |
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内容記述タイプ |
Other |
|
内容記述 |
Dust particles orbiting around a star spiral into the star owing to the drag by stellar photons absorbed and scattered by the dust. This is called the Poynting-Robertson effect (PR effect). Stellar win striking dust also decrease its orbital angular momentum, which we call the plasma PR effect analogous to the photon PR effect. Both photon and plasma PR effects play a role in limiting the lifetime of dust around main-sequence stars. An evaluation of the plasma PR lifetimes requires knowledge of interaction between dust and stellar wind ions, in other words, the momentum transfer cross section. Stellar wind ions are not perfectly absorbed by a dust particle, but penetrate through it if their momentum is sufficiently large. This reduces the momentum transfer cross section of the dust as demonstrated by Minato et al. (2004), who took into account penetration of stellar wind ions for a study of the plasma PR effect. Clearly, realistic estimates of the momentum transfer cross section are the key to better understand the lifetimes of dust particles. In the previous studies concerning the plasma PR effect, dust is for simplicity assumed to be a spherical grain. However, cometary dust is often assumed as fluffy aggregates consisting of smaller grains. Fluffy aggregates of submicron grains are in fact observed as Interplanetary Dust Particles (IDPs). The fluffy structure increases their geometric cross sections compared with a spherical dust of the same volume and, in consequence, may increase their momentum transfer cross sections. If this is the case, the orbital angular momentum of dust aggregates is more efficiently lost compared to that of spherical dust particles. The importance of the plasma PR effect also depends on the stellar-wind parameters. Recently, Wood et al. (2002) have shown that the stellar wind of solar-like stars becomes weaker with the age of the star. Therefore, the plasma PR effect may even play a dominant role in determining the lifetimes of dust particles around young main-sequence stars. We study the plasma PR effect for dust aggregates and its consequences on their lifetimes. We formulate the momentum transfer cross section of a fluffy dust aggregate. We calculate the magnitude of the stellar wind pressure and plasma PR drag forces on dust aggregates to compare with the radiation pressure and photon PR drag forces. The results are applied to evaluate lifetimes for dust orbiting around young and old main-sequence stars. We show that the life time of the debris dust around a young main sequence stars is shorter by orders of magnitude than that estimated by taking account the photon PR effects alone. |
| 資料番号 |
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内容記述タイプ |
Other |
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内容記述 |
資料番号: AA0063350032 |
