标题： 解析核心塌缩超新星：对流是关键吗？ I. 即时对流 显示英文标题

标题： Deciphering Core Collapse Supernovae: Is Convection the Key? I. Prompt Convection

摘要： 我们耦合了二维流体力学与详细的单群限制性扩散中微子输运，以研究核心坍缩超新星中的触发对流。 我们的初始条件、时变边界条件以及用于计算中微子加热、冷却和去轻子化率的中微子分布，均来自实施多群限制性扩散中微子输运和一维流体力学的一维模拟。 对于15和25倍太阳质量模型（分别代表具有紧凑铁核和扩展铁核的两类恒星），我们探讨了触发对流的发展与演化及其对激波动力学的影响。 在没有中微子输运的情况下，两种模型的触发对流发展和耗散的时间尺度均为$\sim$15 毫秒。 触发对流在激波后播种对流，导致激波球对称性的扭曲，但平均而言，激波半径未显著增强。 在存在中微子输运的情况下，触发对流速度相对于整体流入速度太小，无法引起显著的熵和轻子对流传输。 一个简单的解析模型支持我们的数值结果，表明包括输运会将对流增长率和渐近速度降低4到250倍。 显示英文摘要

摘要： We couple two-dimensional hydrodynamics to detailed one-dimensional multigroup flux-limited diffusion neutrino transport to investigate prompt convection in core collapse supernovae. Our initial conditions, time-dependent boundary conditions, and neutrino distributions for computing neutrino heating, cooling, and deleptonization rates are obtained from one-dimensional simulations that implement multigroup flux-limited diffusion neutrino transport and one-dimensional hydrodynamics. The development and evolution of prompt convection and its ramifications for the shock dynamics are investigated for both 15 and 25 solar mass models, representative of the two classes of stars with compact and extended iron cores, respectively. In the absence of neutrino transport, prompt convection develops and dissipates on a time scale $\sim$15 ms for both models. Prompt convection seeds convection behind the shock, which causes distortions in the shock's sphericity, but on the average, the shock radius is not boosted significantly. In the presence of neutrino transport, prompt convection velocities are too small relative to bulk inflow velocities to result in any significant convective transport of entropy and leptons. A simple analytical model supports our numerical results, indicating that the inclusion of transport reduces the convection growth rates and asymptotic velocities by factors of 4--250.