Galaxy merging, the fundamental plane of elliptical galaxies and the MBH-σ0 relation
Galaxy merging, the fundamental plane of elliptical galaxies and the MBH-σ0 relation
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DOI：
10.1046/j.1365-8711.2003.06554.x
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发表时间：
2003-02
影响因子：
4.8
通讯作者：
C. Nipoti;P. Londrillo;L. Ciotti
中科院分区：
文献类型：
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作者：
C. Nipoti;P. Londrillo;L. Ciotti
我们利用基于一种新的高性能数值方案(Dehnen 2002)的N体程序，研究了无耗散合并对椭圆星系基本面的影响。我们研究了星系增长的两个极端情况，即等质量合并和小型恒星系统的吸积；在模拟的一个子集中，我们还考虑了合并星系周围暗物质晕的存在。奇怪的是，我们发现大合并保留了基本面，而在吸积情形下，它的边缘厚度仅被轻微复制，在低角动量合并的情况下，它的厚度显著增加。我们还发现，根据基于简单应用维里定理的初步分析的结果，模拟并不能再现Faber-Jackson和Kormendy关系。最后，我们讨论了我们的结果对MBH-�0和Magorrian关系起源的影响。我们发现，如果黑洞质量线性增加(而Magorrian关系被很好地复制)，无耗散合并不能重现MBH-�0关系；相反，大量发射引力波的黑洞合并重现MBH-�0关系，但不能重现Magorrian关系。我们认为，我们的结果强烈地指出，耗散在早期类型星系的形成和中心超大质量黑洞的增长中发挥了重要作用，从而支持了星系形成和类星体活动之间存在联系的观点。
We explore the effects of dissipationless merging on the Fundamental Plane of elliptical galaxies by using a N-body code based on a new, high performance numerical scheme (Dehnen 2002). We investigate the two extreme cases of galaxy growth by equal mass merging and accretion of small stellar systems; in a subset of simulations we also consider the presence of dark matter halos around the merging galaxies. Curiously, we found that the Fundamental Plane is preserved by major merging, while in the accretion scenario its edge–on thickness is only marginally reproduced, with substantial thickening in the case of merging with low angular momentum. We also found that both the Faber-Jackson and Kormendy relations are not reproduced by the simulations, in accordance with the results of a preliminary analysis based on a simple application of the virial theorem. Finally, we discuss the implications of our results for the origin of the MBH-�0 and Magorrian relations. We found that dissipationless merging is unable to reproduce the MBH-�0 relation, if the black hole masses add linearly (while the Magorrian relation is nicely reproduced); on the contrary a black hole merging with substantial emission of gravitational waves reproduces the MBH-�0 relation but fails at reproducing the Magorrian relation. We argue that our results strongly point towards a major role of dissipation in the formation of early–type galaxies and in the growth of their central supermassive black holes, thus supporting the idea of a link between galaxy formation and QSO activity.