Construction of a solar nebula model considering the effect of magnetic field

考虑磁场影响的太阳星云模型构建

基本信息

批准号：
06832011
负责人：
SEKIYA Minoru
金额：
$ 1.34万
依托单位：
KYUSHU 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：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06832011/
关键词：
solar system solar nebula magnetic field protoplanetary disk chondrule cosmic dust dust 原始式惑星系円盤ダイナモ

项目摘要

(1) Variation of the dissipation rate of the maganetic field due to the settling and the growth of the dust particles in the solar nebula is calculated. As a result, the dissipation rate of the magnetic field is found to decrease due to the settling and the growth of the dust. However, the magnetic field does not grow as to affect the evolution of the solar nebula. (2) The revision of the momentum transfer rate between an electron and a neutron is found to have little effect on the dissipation rate of the magnetic field. (3) Radiative equilibrium temperature of the solar nebula is calculated. As a result, temperature is found to be lower than of Hayashi's model (1981), and there are possibility that the nebula become unstable against convection even if it is transparent. (4) Numerical code of SPH method to calculate the evolution of the solar nebula due to eddy viscosity is developed. (5) Condition of chondrule formation is made clear, by observing compound chondrules and using the gravitational istability condition of the dust layr. Chondrules were probably made in the region much inner than the Asteroid belt. (6) Chemical reactions and condensation process on the dust particles in the protoplanetary disks are calculated. Especially, behavior of CO molecules are investigated in detail. As a result, it is found that almost all the CO molecules condense for less than 20 K, i. e. outer than 200 AU from the central star. (7) Numerical simulation of the entry of cosmic dust is performed. This simulation give the temperature experienced by a cosmic dust as a function of the entry angle and speed into the atmosphere.

（1）计算了由于沉降和太阳星云中尘埃颗粒的生长而导致的魔法场耗散速率的变化。结果，由于灰尘的沉降和生长，发现磁场的耗散速率会降低。但是，磁场不会生长，而是影响太阳星云的演变。（2）发现电子和中子之间的动量转移速率对磁场的耗散率几乎没有影响。（3）计算太阳星云的辐射平衡温度。结果，发现温度低于Hayashi模型（1981），并且即使对流透明，也有可能对对流变得不稳定。（4）开发了SPH方法的数值代码，以计算由于涡流粘度而导致的太阳星云的演变。（5）通过观察化合物软骨并使用灰尘层的重力无能条件，可以清楚地形列形成。软骨可能比小行星带的内部内部制造。（6）计算了原球磁盘中尘埃颗粒上的化学反应和凝结过程。特别是，详细研究了CO分子的行为。结果，发现几乎所有的CO分子凝结小于20 k，i。 e。来自中央恒星的外部超过200个AU。（7）进行宇宙灰尘进入的数值模拟。该模拟使宇宙灰尘的温度与入口角度和大气中的速度相关。