Modeling Merging Galaxies using MINGA - Improving Restricted N-body by Dynamical Friction
Modeling Merging Galaxies using MINGA - Improving Restricted N-body by Dynamical Friction
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DOI：
10.1002/asna.200811079
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发表时间：
2008-10
影响因子：
0.9
通讯作者：
H. P. Petsch;C. Theis
中科院分区：
文献类型：
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作者：
H. P. Petsch;C. Theis
由于参数空间的扩展(以及其他问题)，对相互作用的星系进行建模以重现观测到的系统仍然是一个挑战。轨道和基本星系参数可以通过快速模拟技术来解决，如Toomre和Toomre(1972)在基础工作中应用的限制N体方法。这种方法使今天可以在短时间内研究数百万个模型。经典的受限N体方法的一个困难是丢失了轨道衰变，不允许星系合并。在这里，我们提出了一个扩展的限制N体方法，包括动力摩擦。这种处理方法是通过与一组自洽的合并模拟进行定量比较来开发的。通过改变动力摩擦(形式、强度和方向)，我们为一组超过25万次的模拟选择了最合适的参数。我们的处理表明，我们的处理可靠地再现了宿主和卫星之间质量比高达Q=1/3的合并盘星系的轨道衰变和潮汐特征。我们将该技术应用到基于遗传算法的建模程序Minga中，并给出了第一个结果。(2018Wiley-VCH Verlag GmbH&Co.KGaA，Weinheim)
Modeling interacting galaxies to reproduce observed systems is still a challenge due to the extended parameter space (among other problems). Orbit and basic galaxy parameters can be tackled by fast simulation techniques like the restricted N-body method, applied in the fundamental work by Toomre & Toomre (1972). This approach allows today for the study of millions of models in a short time. One difficulty for the classical restricted N-body method is the missing orbital decay, not allowing for galaxy mergers. Here we present an extension of the restricted N-body method including dynamical friction. This treatment has been developed by a quantitative comparison with a set of self-consistent merger simulations. By varying the dynamical friction (formalism, strength and direction), we selected the best-fitting parameters for a set of more than 250 000 simulations. We show that our treatment reliably reproduces the orbital decay and tidal features of merging disk galaxies for mass ratios up to q = 1/3 between host and satellite. We implemented this technique into our genetic algorithm based modeling code MINGA and present first results. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)