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Origin of olivine particles in comets

彗星中橄榄石颗粒的起源

基本信息

批准号：
02640205
负责人：
MUKAI Tadashi
金额：
$ 1.09万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640205/
关键词：
comets cometary dust origin of the solar system 光散乱光学定数

项目摘要

(1)The optical constants of olivine particles were measure in the wavelengths from 7 mum to 200 mum(Mukai and Koike 1990, Icarus 87, 180). These results have confirmed the hypothesis that olivine is a carrier of a twin-peaked structure in the 10 mum region observed in several-comets.(2)Olivine particles, in general, are condenced at high temperatures(>1500 K). One possibility to explain the coexistence of olivine with icy particles inside the cometary nucleus is a radial transportation of particles near the sun to the region where the comet will be formed. We have examined the radiation pressure forces on porous aggragates to study a motion of olivine fluffy particles(Mukai et al. 1992, Astron. Astrophys. in press). It is found a significant difference of radiation forces on fluffy particles compared with those on compact spheres.(3)We have shown(Mukai 1991, IAU Col. 126, Kluwer, p. 371)that a fragmentation of fluffy dust particles due to electrostatic forces caused by electric charges on irregularly shaped particle plays an important role in the production of very small particles detected in the cometary coma of Comet P/Halley.(4)It is found(Mukai and Mukai 1990, Icarus 86, 257, Mukai et al. 1991, IAU Col. 126, Kluwer, p. 249)that these dust modelsfor fluffy aggregates can explain the photopolarimetric data observed in comets.

(1)测量了橄榄石粒子在7 ~ 200 nm波长范围内的光学常数（Mukai and Koike 1990, Icarus 87,180）。这些结果证实了橄榄石是双峰结构的载体的假设，在一些彗星上观察到的10毫米区域。(2)橄榄石颗粒一般在高温（150 ~ 1500 K）下凝结。解释彗星核内橄榄石与冰粒子共存的一种可能性是，太阳附近粒子向彗星形成区域的径向运输。我们研究了多孔聚集体上的辐射压力，以研究橄榄石蓬松颗粒的运动（Mukai et al. 1992, Astron）。12,54。在出版社)。研究发现，蓬松粒子与致密球体上的辐射力存在显著差异。(3)我们已经证明（Mukai 1991， IAU上校126，Kluwer，第371页），由于不规则形状粒子上的电荷引起的静电力导致蓬松的尘埃粒子碎裂，在p /哈雷彗星彗发中检测到的非常小的颗粒的产生中起着重要作用。(4)发现（Mukai and Mukai 1990, Icarus 85,257, Mukai et al. 1991, IAU . 126, Kluwer, p. 249）这些蓬松聚集体的尘埃模型可以解释在彗星上观测到的光偏振数据。