Dynamical modeling of long-period variable star atmospheres
Dynamical modeling of long-period variable star atmospheres
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DOI：
10.1086/166378
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发表时间：
1988-06
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影响因子：
--
通讯作者：
G. Bowen
中科院分区：
文献类型：
--
作者：
G. Bowen
利用一种新的灵活的计算机程序，进行了数值计算，以研究冷脉动Mira类恒星的球形模型大气的动力学结构和行为，这些恒星的质量从0.8到2.0太阳质量，基本模式脉动周期从175到1000天。特别是，在相当大的范围内的恒星参数的基本模式和泛音模式，各种驱动振幅，以及各种假设所涉及的物理过程的模型，以周期性的驱动在其内部边界的响应进行了检查;辐射压力尘埃和随时间变化的温度松弛包括在内。在所有情况下，稳定的稳态模型与周期性冲击。冲击和尘埃都被认为是快速质量损失所必需的。激波增加了密度，从而大大增加了在寒冷的外层大气中形成的尘埃量。辐射压力加速了这些颗粒，从而驱动了一股缓慢的冷风。计算出的质量损失率似乎是正确的数量级同意与观测，并显示如何质量损失可以预期依赖于恒星参数。42篇参考文献。
Using a new flexible computer program, numerical calculations were performed to investigate the dynamical structure and behavior of a spherical model atmosphere for cool pulsating Mira-like stars with masses from 0.8 to 2.0 solar masses and fundamental-mode pulsation periods from 175 to 1000 days. In particular, the response of the model to periodic driving at its inner boundary was examined for a considerable range of stellar parameters for both fundamental and overtone modes, various driving amplitudes, and various assumptions about the physical processes involved; radiation pressure on dust and time-dependent temperature relaxation were included. Stable steady state models with periodic shocks were obtained in all cases. Both shocks and dust were found to be essential for rapid mass loss. The shocks increase the density and thus greatly increase the amount of dust formed in the cool outer atmosphere. Radiation pressure accelerates the grains, which drive a slow cool wind. Calculated mass-loss rates appear to be of the right order of magnitude to agree with observations and show how mass loss can be expected to depend on the stellar parameters. 42 references.