基于SDSS-DR8及2MASS数据的疏散星团NGC 6791的基本性质研究

发布时间：2018-09-04 18:13

【摘要】：利用斯隆数字巡天(SDSS)第8次释放数据(DR8)的恒星光谱数据及2MASS(Two Micro All Sky Survey)近红外点源测光数据研究著名的疏散星团NGC 6791,得到该星团的视向速度与金属丰度分别为V_r=-46.4±0.2 km·s~(-1)和[Fe/H]=0.32±0.11dex.利用星团中红团簇巨星作为理想"标准烛光",结合2MASS近红外点源测光数据计算了该星团的绝对距离模数为(m-M)_0=13.02±0.08 mag或4.02±0.15 kpc.与其他研究者给出的结果进行了比较,金属丰度、视向速度及绝对距离模数都符合得比较好.主要结论有3点:(1)NGC 6791是个极度富金属的星团;(2)在SDSS的光谱分辨能力以内,分离出的87颗团星之间不存在明显的金属丰度差异;(3)得到的距离模数对年龄、金属丰度及尘埃消光不敏感,是一种可靠的间接测量.
[Abstract]:The star spectral data of the eighth release data (DR8) of the Sloan Digital Sky Survey (DR8) and the 2MASS (Two Micro All Sky Survey) near-infrared point-source photometry data are used to study the famous open cluster NGC 6791. The apparent velocity and metal abundance of the cluster are obtained to be V_r=-46.4 卤0.2 km s-1 and [Fe/H] 0.32 卤0.11dex. respectively. Using red cluster giant as ideal "standard candlelight" and 2MASS near infrared point-source photometry data, the absolute distance modulus of this cluster is (m-M) 013.02 卤0.08 mag or 4.02 卤0.15 kpc.. Compared with the results obtained by other researchers, metal abundance, apparent velocity and absolute distance modulus are in good agreement. The main conclusions are as follows: (1) NGC 6791 is an extremely metal-rich star cluster; (2) within the spectral resolution of SDSS, there is no significant difference in metal abundance among 87 cluster stars separated; (3) the distance modulus pair ages are obtained. Metal abundance and dust extinction are insensitive and are a reliable indirect measurement.
【作者单位】：常州大学信息科学与工程学院;中国科学院上海天文台;
【基金】：常州大学科研启动经费项目(ZMF 1002121) 国家自然科学基金项目(11073038,10833005) 科技部973项目(2007CB815403)资助
【分类号】：P154.11

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