发表机构
Universidad Técnica Federico Santa María; Universidad de Valparaíso; Universidad Mayor; CONICET; Universidad Nacional de La Plata; Instituto de Astrofísica de La Plata（费德里科·圣玛丽亚理工大学; 瓦尔帕莱索大学; 市长大学; 国家科学技术研究委员会; 拉普拉塔国立大学; 拉普拉塔天体物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在旋转B超巨星线驱动风中引入应变限制湍流黏性，发现其作为径向制动项显著降低终速和质量损失率，但保持辐射驱动与平流主导的角动量输运。
AI 中文摘要
大质量恒星的辐射驱动风产生已知本质上是湍流的强大外流。尽管如此，标准流体动力学模型历来将宏观湍流黏性的应用限制在旋转支撑的盘上，忽略了其在风的超音速膨胀区域中的动态作用。我们评估了旋转B超巨星加速线驱动恒星外流中宏观湍流动量输运的动态相关性。我们在FARGO3D代码的稳定、时间依赖的一维m-CAK流体动力学框架内引入了一种广义的应变限制黏性方案。我们比较了无黏性、恒定黏性和应变限制模型，以分析它们对径向速度、密度分层、质量损失率和角动量输运的影响。应变限制方案产生径向结构的黏性，主要作为广泛的径向制动项。通过规定的最大混合长度限制黏性，黏性加速度相对于总辐射加速度保持次主导，但对平流加速度具有动态相关性。在最强黏性模型中，终速相对于无黏性模型在稳态下降低了约39%，质量损失率降低了约58%。流动保持辐射驱动，角动量输运仍由平流主导，维持准守恒的$v_\phi \propto r^{-1}$标度。湍流黏性对超音速线驱动风产生可测量的动态效应。当受局部宏观应变限制时，它修改径向动量平衡和由此产生的质量损失率，而不迫使风进入强黏性角动量再分布的盘状状态。
英文摘要
Radiation-driven winds from massive stars generate powerful outflows known to be intrinsically turbulent. Despite this, standard hydrodynamic models have historically restricted the application of macroscopic turbulent viscosity to rotationally supported disks, neglecting its dynamic role in the supersonic expansion regime of the wind. We evaluated the dynamical relevance of macroscopic turbulent momentum transport in accelerating line-driven stellar outflows of rotating B supergiants. We introduced a generalized strain-limited viscous prescription within a stable, time-dependent 1D m-CAK hydrodynamic framework using the FARGO3D code. We compared inviscid, constant-viscosity, and strain-limited models to analyze their effects on the radial velocity, density stratification, mass-loss rate, and angular momentum transport. The strain-limited prescription produces a radially structured viscosity that primarily acts as a broad radial braking term. With the viscosity bounded through a prescribed maximum mixing length, the viscous acceleration remains subdominant to the total radiative acceleration but is dynamically relevant to the advective acceleration. In the strongest-viscosity model, the terminal velocity decreased by $\sim 39\%$ and the mass-loss rate by $\sim 58\%$ relative to the inviscid model in the stationary state. The flow remains radiatively driven, and angular momentum transport remains dominated by advection, maintaining a quasi-conserving $v_ϕ\propto r^{-1}$ scaling. Turbulent viscosity exerts a measurable dynamic effect on supersonic line-driven winds. When bounded by the local macroscopic strain, it modifies the radial momentum balance and the resulting mass-loss rate without forcing the wind into a disk-like regime of strong viscous angular momentum redistribution.
Comments17 pages, 10 figures. Accepted for publication in The Astrophysical Journal
