论文标题
矮人在矮小球体中的幻象暗物质的分布
Distribution of Phantom Dark Matter in Dwarf Spheroidals
论文作者
论文摘要
在修改后的牛顿动力学（MOND）是正确的重力理论的假设下，我们在围绕银河系的八个经典矮人星系中得出了幻影暗物质的分布。根据他们观察到的形状，我们将矮人建模为轴对称系统，而不是通常假设的球形系统。另外，按照MOND框架的假设要求，我们实际上包括银河系和本地群体以外的大规模结构的外部重力场。对于外部场在内部重力场上占主导地位的矮人，幻影暗物质从恒星分布中取代了〜0.1-0.2 kpc，这取决于采用的质量与光比。该偏移量是矮人半质量半径的很大一部分。对于雕塑家和福纳克斯（Fornax），内部和外部重力场是可比的，幻影暗物质分布似乎在两个磁场相互取消的位置被尖峰打扰。这些特征与矮人中星星的分布几乎没有联系。最后，我们发现由于本地组以外的大规模结构引起的外部田地的影响很小。我们发现的幻影暗物质的特征代表了MOND的真实预测，因此，如果未观察到，我们在这里采用的版本中可以伪造这种重力理论。
We derive the distribution of the phantom dark matter in the eight classical dwarf galaxies surrounding the Milky Way, under the assumption that modified Newtonian dynamics (MOND) is the correct theory of gravity. According to their observed shape, we model the dwarfs as axisymmetric systems, rather than spherical systems, as usually assumed. In addition, as required by the assumption of the MOND framework, we realistically include the external gravitational field of the Milky Way and of the large-scale structure beyond the Local Group. For the dwarfs where the external field dominates over the internal gravitational field, the phantom dark matter has, from the star distribution, an offset of ~0.1-0.2 kpc, depending on the mass-to-light ratio adopted. This offset is a substantial fraction of the dwarf half-mass radius. For Sculptor and Fornax, where the internal and external gravitational fields are comparable, the phantom dark matter distribution appears disturbed with spikes at the locations where the two fields cancel each other; these features have little connection with the distribution of the stars within the dwarfs. Finally, we find that the external field due to the large-scale structure beyond the Local Group has a very minor effect. The features of the phantom dark matter we find represent a genuine prediction of MOND, and could thus falsify this theory of gravity in the version we adopt here if they are not observationally confirmed.
