The fragility of thin discs in galaxies - I. Building tailored N -body galaxy models
The fragility of thin discs in galaxies - I. Building tailored N -body galaxy models
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星系中薄盘的脆弱性 - I. 构建定制的 N 体星系模型
DOI：
10.1093/mnras/stad419
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发表时间：
2023
影响因子：
4.8
通讯作者：
Galán-De Anta P
中科院分区：
文献类型：
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作者：
Galán-De Anta P
薄的恒星盘在银河系和核，sub-kpc尺度被认为是脆弱的结构，将很容易在主要的合并中被破坏。反过来，这使得它们的恒星群的年龄测定成为星系组装历史的有用诊断。我们的目标是仔细探索这种恒星盘的脆弱性，在中等和低质量的遭遇，使用高resolutionN-体模拟的星系模型的结构和运动学特性，适合实际观察到的星系。作为第一个但具有挑战性的一步，我们创建了一个动力学模型FCC 170，一个几乎在天炉座星系团中的边缘星系，具有多个星系组成部分，包括银河系尺度和核恒星盘（NSD），使用详细的运动学数据从多单元光谱探测器和一种新的方法构建基于分布函数的自洽星系模型。然后，我们将这个模型的BN-体实现，并证明它保持平衡，并在许多Gyr上保持其属性，当演化出足够高的粒子数时。然而，NSD更倾向于数值加热，即使在我们最高分辨率的运行中，它的厚度也会在10 Gyr内逐渐增加22%。尽管如此，这些N体模型可以作为合并模拟中实际星系的真实表示。
Thin stellar discs on both galactic and nuclear, sub-kpc scales are believed to be fragile structures that would be easily destroyed in major mergers. In turn, this makes the age dating of their stellar populations a useful diagnostics for the assembly history of galaxies. We aim at carefully exploring the fragility of such stellar discs in intermediate- and low-mass encounters, using high-resolutionN-body simulations of galaxy models with structural and kinematic properties tailored to actually observed galaxies. As a first but challenging step, we create a dynamical model of FCC 170, a nearly edge-on galaxy in the Fornax cluster with multiple galactic components and including both galactic-scale and nuclear stellar discs (NSDs), using detailed kinematic data from the Multi Unit Spectroscopic Explorer and a novel method for constructing distribution function-based self-consistent galaxy models. We then createN-body realizations of this model and demonstrate that it remains in equilibrium and preserves its properties over many Gyr, when evolved with a sufficiently high particle number. However, the NSD is more prone to numerical heating, which gradually increases its thickness by up to 22 per cent in 10 Gyr even in our highest resolution runs. Nevertheless, theseN-body models can serve as realistic representations of actual galaxies in merger simulations.