The formation phase of the solar nebula
The formation phase of the solar nebula
复制标题
太阳星云的形成阶段
DOI：
10.1086/168798
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
J. E. Tohline
中科院分区：
文献类型：
--
作者：
P. Bodenheimer;H. Yorke;M. Rozyczka;J. E. Tohline
给出了轴对称旋转原恒星云在有辐射输运和无磁场的情况下坍塌的流体力学计算。崩塌假设是从一个中心凝聚球开始的，半径为5×10到15厘米，平均密度为4×10到-15克/立方厘米，总质量为1个太阳质量，总角动量为10到53克平方厘米每秒。采用数值网格对距中心1~60AU的圆盘形成区进行了数值求解。频率相关的辐射传输计算表明，结构的出射光谱如何取决于相对于旋转轴的视角，以及观测到的等光线轮廓应该如何取决于波长和视角。原恒星的中心部分，在1AU的内部，不是数值解析的，而是近似模拟的。在计算结束时，我们发现这个区域的质量为0.6个太阳质量，转动能与引力能之比约为0.4，大到足以产生不稳定的非轴对称微扰。虽然根据局部Toomre判据，圆盘的引力是稳定的，但中心的非轴对称结构很可能导致角动量输运。参考文献77篇。
Hydrodynamical calculations of the collapse of an axisymmetric, rotating protostellar cloud, with radiation transport and without magnetic fields, are presented. The collapse is assumed to start from a centrally condensed sphere of radius 5 x 10 to the 15th cm, a mean density of 4 x 10 to the -15th g/cu cm, a total mass of 1 solar mass, and a total angular momentum of 10 to the 53rd g sq cm per sec. The numerical grid is chosen to resolve the region of disk formation between 1 and 60 AU from the center. Frequency-dependent radiative transfer calculations show how the emergent spectrum of the structure depends upon viewing angle with respect to the rotation axis and how the observed isophotal contours should depend on wavelength and viewing angle. The central part of the protostar, interior to 1 AU, is not resolved numerically but is modeled approximately. At the end of the calculation, this region is found to have a mass of 0.6 solar mass and a ratio of rotational to gravitational energy of about 0.4, sufficiently large to be unstable to nonaxisymmetric perturbations. Although the disk is gravitationally stable according to the local Toomre criterion, the nonaxisymmetric structure inmore » the center is likely to lead to angular momentum transport. 77 refs.« less