论文标题
隔离星系的SPH模拟中的尘埃扩散
Dust diffusion in SPH simulations of an isolated galaxy
论文作者
论文摘要
我们使用$ n $ body/平滑的粒子 - 杂草动力学代码{\ sc gadget-4}来计算晶粒尺寸分布（GSD）的演变（GSD）。将完整的GSD在带有30箱的对数间隔网格上进行采样，并使用最先进的恒星形成和反馈模型，使用银河系的流体动力和化学演化来自我计算。在该模型的先前版本中，GSD倾向于略微偏向更大的晶粒，而灭绝曲线的趋势比观测值倾向。这项工作通过考虑亚网格尺度上的湍流来考虑灰尘和金属的扩散，并引入了多相亚网格模型，从而使从弥散到密集气体的更平滑过渡。我们表明，扩散可以显着增强小晶粒的产生，并以银河系方式与观察到的尘埃灭绝曲线提高一致性。
We compute the evolution of the grain size distribution (GSD) in a suite of numerical simulations of an isolated Milky-Way-like galaxy using the $N$-body/smoothed-particle-hydrodynamics code {\sc Gadget-4}. The full GSD is sampled on a logarithmically spaced grid with 30 bins, and its evolution is calculated self-consistently with the hydrodynamical and chemical evolution of the galaxy using a state-of-the-art star formation and feedback model. In previous versions of this model, the GSD tended to be slightly biased towards larger grains and the extinction curve had a tendency to be flatter than the observations. This work addresses these issues by considering the diffusion of dust and metals through turbulence on subgrid scales and introducing a multi-phase subgrid model that enables a smoother transition from diffuse to dense gas. We show that diffusion can significantly enhance the production of small grains and improve the agreement with the observed dust extinction curve in the Milky Way.
