论文标题
VVV CL001群集的光谱分析与缪斯
Spectroscopic analysis of VVV CL001 cluster with MUSE
论文作者
论文摘要
像大多数螺旋星系一样,银河系也包含蓝色的金属贫困球状簇和另一个红色,金属丰富的簇。后者的大部分属于凸起,因此与蓝色(光晕)相比,它们的研究很差,因为它们遭受了较高的灭绝和较大的污染物的污染物。这些内在的困难以及缺乏低质量的凸起球状簇,这是相信他们的人口普查还不完整的原因。确实,在过去的几年中,已经确认了一些新簇。其中之一是本研究的主题VVV CL001。我们对最近确认的球形群集VVV CL001进行了新的光谱分析,该分析是由Muse@vlt Integral Field数据进行的。在VVV CL001场中提取单个光谱。径向速度是通过与合成模板的互相关得出的。再加上VVV调查中的PMS,这些数据使我们能够选择55个潜在的群集成员,我们使用大炮的公共代码来得出金属性。簇的平均径向速度为Vhelio = -324.9 +-0.8 km/s,如55个簇成员所估计。这种高速度以及低金属性[Fe/h] = -2.04 +-0.02 dex表明VVV Cl001可能是一个非常古老的簇。估计的距离为d = 8.23 +-0.46 kpc,将簇放在银河凸出中。此外,其当前位置和轨道参数都表明VVV CL001很可能是一个凸起的球状簇。
Like most spiral galaxies, the Milky Way contains a population of blue, metal-poor globular clusters and another of red, metal-rich ones. Most of the latter belong to the bulge, and therefore they are poorly studied compared to the blue (halo) ones because they suffer higher extinction and larger contamination from field stars. These intrinsic difficulties, together with a lack of low-mass bulge globular clusters, are reasons to believe that their census is not complete yet. Indeed, a few new clusters have been confirmed in the last few years. One of them is VVV CL001, the subject of the present study. We present a new spectroscopic analysis of the recently confirmed globular cluster VVV CL001, made by means of MUSE@VLT integral field data. Individual spectra were extracted for stars in the VVV CL001 field. Radial velocities were derived by cross-correlation with synthetic templates. Coupled with PMs from the VVV survey, these data allow us to select 55 potential cluster members, for which we derive metallicities using the public code The Cannon. The mean radial velocity of the cluster is Vhelio = -324.9 +- 0.8 km/s,as estimated from 55 cluster members. This high velocity, together with a low metallicity [Fe/H] = -2.04 +- 0.02 dex suggests that VVV CL001 could be a very old cluster. The estimated distance is d = 8.23 +- 0.46 kpc, placing the cluster in the Galactic bulge. Furthermore, both its current position and the orbital parameters suggest that VVV CL001 is most probably a bulge globular cluster.