星系中的σ-drop与σ-金属度简并
Sigma-drop in galaxies and the sigma-metallicity degeneracy
摘要：
在某些星系中，中心速度色散σ相对于周围是低的。这种下降现象可能有不同的物理起源，承载着宿主星系内部动力学的信息。在这篇文章中，我们强调的重要性，也是由于观测文物的sigma金属丰度简并：当人口的光谱与模板的不匹配的金属丰度进行比较，速度色散可能会被错误地估计。σ下降可能出现在金属丰度峰的位置。讨论说明使用VLT/FORS光谱的弥漫椭圆星系。一些sigma-drop星系的文献报道可能是分析文物。
英文摘要：
In some galaxies, the central velocity dispersion, sigma, is depressed with respect to the surroundings. This sigma-drop phenomenon may have different physical origins, bearing information about the internal dynamics of the host galaxy. In this article, we stress the importance also of observational artifacts due to the sigma-metallicity degeneracy: when a spectrum of a population is compared with a template of miss-matched metallicity, the velocity dispersion may be wrongly estimated. A sigma-drop may appear in place of a metallicity peak. The discussion is illustrated using VLT/FORS spectra of diffuse elliptical galaxies. Some of the sigma-drop galaxies reported in the literature may be analysis artifacts.
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。
