The Milky Way nuclear star cluster beyond 1 pc
The Milky Way nuclear star cluster beyond 1 pc
复制标题
银河系核星团超过1颗
DOI：
10.1017/s1743921314000611
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
C. J. Walcher
中科院分区：
文献类型：
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作者：
A. Feldmeier;N. Neumayer;A. Seth;P. T. de Zeeuw;R. Schodel;N. Lutzgendorf;M. Kissler-Patig;S. Nishiyama;C. J. Walcher
在银河系中央10 pc的范围内，有一个密集的星团，即核星星团，构成了银河系的一个独特组成部分。核星星团是常见的天体，在75%的邻近星系中被探测到。然而，人们并不完全理解核簇是如何形成的。由于银河系核心星星团的距离只有8千秒差距，我们可以在空间上解决它的恒星种群和运动学比外部星系好得多。我们利用近红外长缝光谱仪ISAAC（VLT）的漂移扫描技术，获得了银河系中央10 × 8pc的积分场光谱图，获得了前所未有的数据集。为了补充我们的数据集，我们还观察到的领域的距离为沿着银河plane解开核恒星diskid.From这个数据集的影响，我们提取的恒星运动学地图使用CO bandheads和发射线运动学地图使用H2发射线。利用恒星运动学理论，建立了银河系核心星星团的运动学模型，导出了核心星团的质量，并对中心星系势进行了约束。由于银河系中的黑洞质量是精确已知的，因此该运动学数据集也将作为测试外部星系中使用的黑洞质量建模技术的基准。
Within the central 10 pc of our Galaxy lies a dense cluster of stars, the nuclear star cluster, forming a distinct component of our Galaxy. Nuclear star clusters are common objects and are detected in ∼75% of nearby galaxies. It is, however, not fully understood how nuclear clusters form. Because the Milky Way nuclear star cluster is at a distance of only 8 kpc, we can spatially resolve its stellar populations and kinematics much better than in external galaxies. This makes the Milky Way nuclear star cluster a reference object for understanding the structure and assembly history of all nuclear star clusters.We have obtained an unparalleled data set using the near-infrared long-slit spectrograph ISAAC (VLT) in a novel drift-scan technique to construct an integral-field spectroscopic map of the central ∼10 × 8 pc of our Galaxy. To complement our data set we also observed fields out to a distance of ∼19 pc along the Galactic plane to disentangle the influence of the nuclear stellar disk.From this data set we extract a stellar kinematic map using the CO bandheads and an emission line kinematic map using H2 emission lines. Using the stellar kinematics, we set up a kinematic model for the Milky Way nuclear star cluster to derive its mass and constrain the central Galactic potential. Because the black hole mass in the Milky Way is precisely known, this kinematic data set will also serve as a benchmark for testing black hole mass modeling techniques used in external galaxies.