We developed a 3-D elastic Boundary Element Method (BEM) computer code, called AstroSeis, to model seismic wavefields in a body with an arbitrary shape, such as an asteroid. Besides the AstroSeis can handle arbitrary surface topography, it can deal with a liquid core in an asteroid model. Both the solid and liquid domains are homogenous in our current code. For seismic sources, we can use single forces or moment tensors. The AstroSeis is implemented in the frequency domain and the frequency-dependent Q can be readily incorporated. The code is in MATLAB and it is straightforward to set up the model to run our code. The frequency-domain calculation is advantageous to study the long-term elastic response of a celestial body due to a cyclic force such as the tidal force with no numerical dispersion issue suffered by many other methods requiring volume meshing. Our AstroSeis has been benchmarked with other methods such as normal modes summation and the direct solution method (DSM). This open-source AstroSeis will be a useful tool to study the interior and surface processes of asteroids.

中文翻译：

---

AstroSeis：不规则小行星和天体地震波场的 3D 边界元建模代码

我们开发了一种名为 AstroSeis 的 3-D 弹性边界元方法 (BEM) 计算机代码，用于模拟具有任意形状的物体（例如小行星）中的地震波场。除了 AstroSeis 可以处理任意表面地形外，它还可以处理小行星模型中的液体核心。在我们当前的代码中，固体域和液体域都是同质的。对于震源，我们可以使用单个力或力矩张量。AstroSeis 是在频域中实现的，并且可以很容易地合并与频率相关的 Q。代码在 MATLAB 中，设置模型以运行我们的代码很简单。频域计算有利于研究由循环力（例如潮汐力）引起的天体的长期弹性响应，而没有许多其他需要体网格划分的方法所遇到的数值色散问题。我们的 AstroSeis 已使用其他方法进行了基准测试，例如正常模式求和和直接求解方法 (DSM)。这个开源的 AstroSeis 将成为研究小行星内部和表面过程的有用工具。