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arXiv 1001.0696astro-ph.SR
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非常年轻疏散星团NGC6383恒星形成的光度和光谱研究

A photometric and spectroscopic investigation of star formation in the very young open cluster NGC6383

G. Rauw, J. Manfroid, M. De Becker

摘要:

以O型双星HD 159176为中心的非常年轻的疏散星团NGC 6383是研究具有强辐射场和强风的早型恒星对低质量恒星形成过程影响的一个有趣的地方。为了研究这一过程,有必要确定星团中低质量主序前(PMS)恒星的特征(年龄,存在或不存在星周物质)。我们获得了整个星团的深U B V(R I)_c H-α光度数据以及X射线选定天体的子样本的中分辨率光谱。我们的光谱数据显示,只有非常弱的H-α发射线在一些X射线选择PMS候选人。我们光度确定了一些H-α发射候选人,但他们的集群成员是不确定的。我们发现,在视场中较暗的天体有很宽的消光范围(A_V = 20),一颗X射线选择的OB星的A_V ~ 8。我们的研究揭示了NGC 6383中的PMS星群,它们可能与HD 159176同时代。此外,我们检测到一个人口的变红的对象,可能位于不同的深度内的出生分子云的集群。最后,我们确定了一个相当复杂的空间分布的H-α发射体,这可能是一个严重的污染前景和背景恒星的指示。

英文摘要:

The very young open cluster NGC 6383 centered on the O-star binary HD 159176 is an interesting place for studying the impact of early-type stars with strong radiation fields and powerful winds on the formation processes of low-mass stars. To investigate this process, it is necessary to determine the characteristics (age, presence, or absence of circumstellar material) of the population of low-mass pre-main-sequence (PMS) stars in the cluster. We obtained deep U B V (R I)_c H-alpha photometric data of the entire cluster as well as medium-resolution optical spectroscopy of a subsample of X-ray selected objects. Our spectroscopic data reveal only very weak H-alpha emission lines in a few X-ray selected PMS candidates. We photometrically identify a number of H-alpha emission candidates but their cluster membership is uncertain. We find that the fainter objects in the field of view have a wide range of extinction (up to A_V = 20), one X-ray selected OB star having A_V ~ 8. Our investigation uncovers a population of PMS stars in NGC 6383 that are probably coeval with HD 159176. In addition, we detect a population of reddened objects that are probably located at different depths within the natal molecular cloud of the cluster. Finally, we identify a rather complex spatial distribution of H-alpha emitters, which is probably indicative of a severe contamination by foreground and background stars.

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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