光学薄冷却曲线对凝结形成的影响：利用热不稳定性的个例研究
Effect of optically thin cooling curves on condensation formation: Case study using thermal instability
摘要：
在许多天体物理环境中都观测到了非引力引起的凝聚。这种结构是由于光学薄辐射发射的能量损失而形成的。在数值模拟中通常使用预先计算的冷却曲线，而不是求解完整的辐射转移方程。在文献中，存在各种各样的冷却曲线，它们经常被用作毫无疑问的成分。我们确定的光学薄冷却曲线上的冷凝的形成和演变的效果。我们进行了一个案例研究，使用热不稳定性作为一种机制，形成原位冷凝。我们比较了二维数值模拟与不同的冷却曲线，使用相互作用的慢磁流体动力学（MHD）波作为触发器的热不稳定性。此外，我们还讨论了一种自举测度来研究热不稳定性的远非线性区域。在附录中，我们包括了MPI-AMRVAC中实现的所有冷却曲线的细节，并简要讨论了用于热不稳定性的慢MHD波设置的流体动力学变体。对于所有测试的冷却曲线，形成冷凝。然而，热不稳定性的增长率是不同的。此外，所形成的冷凝物的形态变化很大。我们发现破碎的冷却曲线的低温处理的影响。冷凝形成的冷却曲线消失的温度低于20 000 K似乎是更稳定的动力学不稳定性。在流体动力学的情况下，非线性制度和破碎的MHD的情况下有很大的不同。我们提倡使用基于精确计算和最新原子参数和太阳丰度的现代冷却曲线。我们的自助程序可以用于未来的多维模拟，研究精细结构的动力学在太阳能电池。
英文摘要：
Non-gravitationally induced condensations are observed in many astrophysical environments. Such structures are formed due to energy loss by optically thin radiative emission. Instead of solving the full radiative transfer equations, precomputed cooling curves are typically used in numerical simulations. In the literature, there exists a wide variety of cooling curves and they are quite often used as unquestionable ingredients. We determine the effect of the optically thin cooling curves on the formation and evolution of condensations. We perform a case study using thermal instability as a mechanism to form in situ condensations. We compare 2D numerical simulations with different cooling curves using interacting slow magnetohydrodynamic (MHD) waves as trigger for the thermal instability. Furthermore, we discuss a bootstrap measure to investigate the far non-linear regime of thermal instability. In the appendix, we include the details of all cooling curves implemented in MPI-AMRVAC and briefly discuss a hydrodynamic variant of the slow MHD waves setup for thermal instability. For all tested cooling curves, condensations are formed. However, the growth rates of the thermal instability are different. Also, the morphology of the formed condensation widely varies. We find fragmentation that is affected by the low-temperature treatment of the cooling curves. Condensations formed using cooling curves that vanish for temperatures lower than 20 000 K seem to be more stable against dynamical instabilities. The non-linear regime and fragmentation in the hydrodynamic case differ greatly from the MHD case. We advocate the use of modern cooling curves, based on accurate computations and up-to-date atomic parameters and solar abundances. Our bootstrap procedure can be used in future multi-dimensional simulations, to study fine-structure dynamics in solar prominences.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
