中等质量恒星星风物质损失的机制

The Mechanism of the Mass-loss of Stellar Wind for Intermediate-mass Stars

在考虑引力对星风物质损失的制约效果及辐射压与湍流压对其扰动效果的同时,通过引入可压缩流机制,考虑了恒星外壳对流区对星风物质损失的促进作用,从而建立了新的星风物质损失公式.之后,通过对3～5 M_⊙恒星理论模型的星风物质损失率计算,发现:从主序直至中心氦核燃烧结束阶段,新的星风物质损失公式计算所得星风物质损失率与经典星风物质损失公式计算结果几乎一致;而在TP-AGB阶段,应用新的星风物质损失公式计算的恒星模型则不受光度影响产生了持续的较大的星风物质损失,比较符合实际观测结果.

Simultaneously considering the effects of the restriction of the gravitation, the perturbation from the radiation pressure and the turbulence pressure, and the promotion from the convective region in the outer shell of a star by introducing the compressible fluid mechanism, a new formula of the mass-loss of stellar wind is built up in this paper. The stars with initial masses in the range of 3 ≤ M/M⊙ ≤ 5 have evolved from the main-sequence phase to the end of asymptotic giant branch （AGB）. The mass-loss rates with the new formula are in excellent agreement with those with the classical mass-loss formula from the main-sequence phase to the stage of the end of the central helium burning. However, the fluctuation of mass-loss rate with the classical formula has arisen at the end of AGB because of the effect of the surface luminosity. On the contrary, the continuous major mass-loss has been obtained with the new formula at the end of AGB. It is concluded that the mass-loss derived with the new formula is comparatively consistent with the observational results.