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arXiv 0901.4861astro-ph.COastro-ph.GA
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矮星系等密度核中动力学摩擦抑制的检验

The test for suppressed dynamical friction in a constant density core of dwarf galaxies

Shigeki M. Inoue

摘要:

动力学摩擦问题是关于矮星系中球状星团(以下简称GCs)的一个长期难题。在矮星系中,GC受到动力学摩擦的强烈影响,并被认为会落入星系中心。但是,GC确实存在于矮星系中。提出了解决问题的方法。如果矮星系的核心有一个密度恒定的暗物质晕,那么动力学摩擦的影响将大大减弱,GCs应该能够存活到宇宙年龄之后。该解认为,在有核暗晕中,动力学摩擦的抑制是由于暗晕与GC相互作用形成的一个新的平衡态引起的,在这个平衡态中,部分暗晕随GC转动(同向转动态).在这项研究中,我测试的解决方案是否是合理的,并重新考虑为什么一个恒定的密度,核心晕抑制动力学摩擦,通过N体模拟。因此,我的结论是,真正的机制抑制动力学摩擦是不是同向旋转状态,虽然核心晕实际上可以抑制动力学摩擦GC显着。

英文摘要:

The dynamical friction problem is a long-standing dilemma about globular clusters (hereafter,GCs) belonging to dwarf galaxies. GCs are strongly affected by dynamical friction in dwarf galaxies, and are presumed to fall into the galactic center. But, GCs do exist in dwarf galaxies generally. A solution of the problem has been proposed. If dwarf galaxies have a core dark matter halo which has constant density distribution in its center, the effect of dynamical friction will be weakened considerably, and GCs should be able to survive beyond the age of the universe. Then, the solution argued that, in a cored dark halo, the suppression of dynamical friction is caused by a new equilibrium state constructed by the interaction between the halo and the GC, in which a part of the halo rotates along with the GC (co-rotating state). In this study, I tested whether the solution is reasonable and reconsidered why a constant density, core halo suppresses dynamical friction, by means of N-body simulations. As a result, I conclude that the true mechanism of suppressed dynamical friction is not the co-rotating state, although a core halo can actually suppress dynamical friction on GCs significantly.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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