论文标题
行星星云的中央恒星的恒星风模型
Stellar wind models of central stars of planetary nebulae
论文作者
论文摘要
快速线驱动的恒星风在行星星云的演变中起着重要作用。我们提供行星星云中央恒星的全球热星风模型。这些模型预测风结构，包括质量减少速率，终端速度和来自基本恒星参数的新兴通量。我们将风码应用于对应于渐近巨型分支和白矮人相之间进化阶段的参数。我们研究金属性和风质不均匀性（结块）对风能的影响。恒星离开渐近巨型分支之后，线驱动的风很早就出现了（最初以$ t_ \ rm {eff} \ oit10 \，$ kk），并在白矮人冷却轨道上褪色（低于$ t_ \ rm {eff} = 105 \，$ kk）。他们的质量损失率主要是凭借出色的发光度缩放，因此，在从赫尔茨斯普朗·罗塞尔图的红色到蓝色部分的过渡期间，质量损失率仅略有变化。单调行为有以下两个例外：双重性的跳高约为$ 20 \ $ kk，由于铁电离的变化，质量减少率降低了几倍（在进化过程中），而额外的最高最高为$ t_ \ rm {eff} = 40-50-50-50-50-50-50-50 \，$ kk。另一方面，终端速度从大约几百美元{km} \，\ rm {s}^{ - 1} $增加到几千$ \ rm {km} \，\ rm {km} \，\ rm {s}^{s}^{ - 1}^{ - 1} $ senlar a rad s n of stellar aftelrar rad s nius conellar rad rad rad s nipe s nipe s nipe s nipe s nipe s of stellar rad rad rad rad rad rad rad rad rad rad rad rad rad rad rad rad rad rad rad rad rad rad s nius。在双重速度跳跃时，风最终速度也显着增加。派生的风参数合理地与观测值一致。在双侧跳跃的热侧，结块的效果比在凉爽的一侧更强。派生的拟合与风参数可用于进化模型和行星星云形成的研究。预测的质量减少率的跃升性会导致额外的行星星云外观出现。
Fast line-driven stellar winds play an important role in the evolution of planetary nebulae. We provide global hot star wind models of central stars of planetary nebulae. The models predict wind structure including the mass-loss rates, terminal velocities, and emergent fluxes from basic stellar parameters. We applied our wind code for parameters corresponding to evolutionary stages between the asymptotic giant branch and white dwarf phases. We study the influence of metallicity and wind inhomogeneities (clumping) on the wind properties. Line-driven winds appear very early after the star leaves the asymptotic giant branch (at the latest for $T_\rm{eff}\approx10\,$kK) and fade away at the white dwarf cooling track (below $T_\rm{eff}=105\,$kK). Their mass-loss rate mostly scales with the stellar luminosity and, consequently, the mass-loss rate only varies slightly during the transition from the red to the blue part of the Hertzsprung-Russell diagram. There are the following two exceptions to the monotonic behavior: a bistability jump at around $20\,$kK, where the mass-loss rate decreases by a factor of a few (during evolution) due to a change in iron ionization, and an additional maximum at about $T_\rm{eff}=40-50\,$kK. On the other hand, the terminal velocity increases from about a few hundreds of $\rm{km}\,\rm{s}^{-1}$ to a few thousands of $\rm{km}\,\rm{s}^{-1}$ during the transition as a result of stellar radius decrease. The wind terminal velocity also significantly increases at the bistability jump. Derived wind parameters reasonably agree with observations. The effect of clumping is stronger at the hot side of the bistability jump than at the cool side. Derived fits to wind parameters can be used in evolutionary models and in studies of planetary nebula formation. A predicted bistability jump in mass-loss rates can cause the appearance of an additional shell of planetary nebula.
