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arXiv 0803.3806astro-ph
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NGC 1399的中心K波段运动学和谱线强度图

Central K-band kinematics and line strength maps of NGC 1399

M. Lyubenova, H. Kuntschner, D. R. Silva

摘要:

在本文中,我们提出了第一次高空间分辨率K波段地图的中心运动学和近红外光谱特性的巨型cD星系的天炉座星系团,NGC 1399。我们证实了在以前的长缝研究中看到的半径< 0.2”的中心速度色散倾角的存在。我们的速度色散图提供了证据,在这个中心区域的非对称结构,显示三个西格玛峰的东北,东南和西部的星系中心。此外,我们测量了NGC 1399中前所未有的空间分辨率的近红外线强度指数。在我们的二维线强度图中,我们观察到的最重要的特征是Na I和CO(2-0)线强度在星系核区域的下降,在空间上与σ的下降相吻合。观测到的谱线强度和速度色散变化表明,NGC 1399的中心存在一个动态冷子系统,该子系统具有明显的恒星星族。

英文摘要:

In this paper we present for the first time high spatial resolution K-band maps of the central kinematical and near-infrared spectral properties of the giant cD galaxy in the Fornax cluster, NGC 1399. We confirm the presence of a central velocity dispersion dip within radius < 0.2" seen in previous long-slit studies. Our velocity dispersion maps give evidence for a non-symmetric structure in this central area by showing three sigma peaks to the north-east, south-east and west of the galaxy centre. Additionally we measure near-IR line strength indices at unprecedented spatial resolution in NGC 1399. The most important features we observe in our 2-dimensional line strength maps are drops in Na I and CO(2-0) line strength in the nuclear region of the galaxy, coinciding spatially with the drop in sigma. The observed line strength and velocity dispersion changes suggest a scenario where the centre of NGC 1399 harbours a dynamically cold subsystem with a distinct stellar population.

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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