The Published Extended Rotation Curves of Spiral Galaxies: Confrontation with Modified Dynamics
The Published Extended Rotation Curves of Spiral Galaxies: Confrontation with Modified Dynamics
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DOI：
10.1086/178131
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发表时间：
1996-06
期刊：
影响因子：
--
通讯作者：
R. Sanders
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文献类型：
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作者：
R. Sanders
在米尔格罗姆修正动力学(MOND)的背景下，对22个旋涡星系的旋转曲线样本进行了研究，这些曲线是在21厘米中性氢的线上测量的。与贝格曼等人之前高度精选的样本相结合，这构成了当前星系的总样本，其中包含已公布的(或可用的)延长的旋转曲线和光分布的光度观测。这是目前对星系可见质量和经典动力学质量之间差异的定量理解的观测基础。结果表明，用简单的MOND公式由观测到的发光物质和气体的分布计算出的引力可以解释这22条旋转曲线的总体形状和幅度，在某些情况下，预测的曲线与观测到的旋转曲线细节上是一致的。在13种情况下，拟合的旋转曲线只有一个自由参数，即发光盘的质光比；在9种情况下，有一个附加的自由参数，即中心凸起或光集中的M/L。全球M/L(凸起加圆盘)的值是合理的，当计入气体质量时，显示出与Tully-Fisher关系中一致的散射。MOND公式成功地预测了这个更大、选择不那么严格的样本的旋转曲线，进一步支持了动力学或重力在低加速极限下是非牛顿的，没有必要援引大量不可见物质的存在。
A sample of 22 spiral galaxy rotation curves, measured in the 21 cm line of neutral hydrogen, is considered in the context of Milgrom's modified dynamics (MOND). Combined with the previous, highly selected sample of Begeman et al., this constitutes the current total sample of galaxies with published (or available) extended rotation curves and photometric observations of the light distribution. This is the observational basis of present quantitative understanding of the discrepancy between the visible mass and classical dynamical mass in galaxies. It is found that the gravitational force calculated from the observed distribution of luminous material and gas by use of the simple MOND formula can account for the overall shape and amplitude of these 22 rotation curves, and in some cases, the predicted curve agrees with the observed rotation curve in detail. The fitted rotation curves have, in 13 cases, only one free parameter, which is the mass-to-light ratio of the luminous disk; in nine cases, there is an additional free parameter, which is M/L of a central bulge or light concentration. The values of the global M/L (bulge plus disk) are reasonable and, when the gas mass is also included, show a scatter consistent with that in the Tully-Fisher relation. The success of the MOND prescription in predicting the rotation curves in this larger, less stringently selected sample lends further support to the idea that dynamics or gravity is non-Newtonian in the limit of low acceleration and that it is unnecessary to invoke the presence of large quantities of unseen matter.