论文标题
二进制对矮星系的动态质量估计的影响
The impact of binaries on the dynamical mass estimate of dwarf galaxies
论文作者
论文摘要
二进制恒星被认为在推动恒星系统的动态演化以及确定其某些观测特征方面很重要。在这项研究中，我们探讨了二进制恒星在调节恒星系统速度分散估计中的作用。为此，我们开发了一种工具，该工具允许研究合成速度分散体对表征二进制含量的许多关键量的依赖性：二元分数及其质量比，偏心率和半高轴的分布。作为一种应用，我们评估了二进制恒星对矮球体和超生产矮人的动态质量估计的影响，发现它可能特别相关，尤其是对于低质量和低密度系统。这些结果对在此类系统中测得的速度分散体的解释产生了深远的影响，因为它削弱或减轻了需要大量暗物质的主张。
Binary stars are recognized to be important in driving the dynamical evolution of stellar systems and also in determining some of their observational features. In this study, we explore the role that binary stars have in modulating the estimates of the velocity dispersion of stellar systems. To this aim, we developed a tool which allows to investigate the dependence of synthetic velocity dispersion on a number of crucial quantities characterizing the binary content: binary fraction and the distributions of their mass ratio, eccentricity and semi-major axis. As an application, we evaluate the impact that binary stars have on the estimation of the dynamical mass of dwarf spheroidal and ultra-faint dwarf galaxies, finding that it can be particularly relevant, especially for low mass and low density systems. These results bear profound implications for the interpretation of the measured velocity dispersion in such systems, since it weakens or relieves the claim for the need of large amounts of dark matter.
