Accurate modeling of galaxy formation in a hierarchical, cold dark matter universe requires the use of sufficiently high-resolution merger trees to obtain convergence in the predicted properties of galaxies. When semi-analytic galaxy formation models are applied to cosmological N-body simulation merger trees, it is often the case that those trees have insufficient resolution to give converged galaxy properties. We demonstrate a method to augment the resolution of N-body merger trees by grafting in branches of Monte Carlo merger trees with higher resolution, but which are consistent with the pre-existing branches in the N-body tree. We show that this approach leads to converged galaxy properties.

中文翻译：

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通过增加N体合并树实现星系形成模型的收敛

在分层的冷暗物质宇宙中对星系形成进行精确建模需要使用足够高分辨率的合并树，以使星系的预测属性收敛。将半解析星系形成模型应用于宇宙N体模拟合并树时，通常情况下，这些树的分辨率不足以提供聚合的星系特性。我们演示了一种方法，该方法通过以更高的分辨率嫁接在蒙特卡罗合并树的分支中来增加N体合并树的分辨率，但该方法与N体树中现有的分支一致。我们证明了这种方法导致了聚合星系特性。