论文标题
使用Gaia和Lamost探索开放群集特性
Exploring open cluster properties with Gaia and LAMOST
论文作者
论文摘要
在Gaia DR2中，在亚MAS中达到的前所未有的高精度水平以用于光度法的天体和MMAG。使用在Gaia DR2中使用这些天体和光度法识别的群集成员，我们可以获得群集特性的可靠确定。但是，由于Gaia光谱观察到处理密集拥挤的聚类区域的缺点，因此仍缺乏Gaia Dr2的簇群体恒星的径向速度和金属性的数量。在这项研究中，我们旨在通过组合杆光谱来改善簇特性。特别是，我们将光谱参数作为Lamost DR5中的附加值目录提供群集成员的列表，可用于通过使用宿主群集的光谱和基本属性来对其进行详细研究，以更好地了解恒星性质。我们与cantat-gaudin等人的识别群集成员进行了交叉匹配的光谱目录。2018，然后使用具有光谱参数的成员来得出开放簇的统计特性。我们获得了具有光谱参数和295个群集特性的目录的8811个成员的列表。 In addition, we study the radial and vertical metallicity gradient and age-metallicity relation with the compiled open clusters as tracers, finding slopes of -0.053$\pm$0.004 dex kpc$^{-1}$, -0.252$\pm$0.039 dex kpc$^{-1}$ and 0.022$\pm$0.008 dex Gyr $^{ - 1} $。年轻簇的金属分布关系的两个斜率（0.1 Gyr <age <2 Gyr）和6 Gyr中簇的年龄金属关系与文献结果一致。为了充分研究磁盘中的化学演化历史，需要对旧且遥远的开放群集进行更多的光谱观测以进行进一步研究。
In Gaia DR2, the unprecedented high-precision level reached in sub-mas for astrometry and mmag for photometry. Using cluster members identified with these astrometry and photometry in Gaia DR2, we can obtain a reliable determination of cluster properties. However, because of the shortcoming of Gaia spectroscopic observation in dealing with densely crowded cluster region, the number of radial velocity and metallicity for cluster member stars from Gaia DR2 is still lacking. In this study, we aim to improve the cluster properties by combining the LAMOST spectra. In particular, we provide the list of cluster members with spectroscopic parameters as an add-value catalog in LAMOST DR5, which can be used to perform detailed study for a better understanding on the stellar properties, by using their spectra and fundamental properties from the host cluster. We cross-matched the spectroscopic catalog in LAMOST DR5 with the identified cluster members in Cantat-Gaudin et al.2018 and then used members with spectroscopic parameters to derive statistical properties of open clusters. We obtained a list of 8811 members with spectroscopic parameters and a catalog of 295 cluster properties. In addition, we study the radial and vertical metallicity gradient and age-metallicity relation with the compiled open clusters as tracers, finding slopes of -0.053$\pm$0.004 dex kpc$^{-1}$, -0.252$\pm$0.039 dex kpc$^{-1}$ and 0.022$\pm$0.008 dex Gyr$^{-1}$, respectively. Both slopes of metallicity distribution relation for young clusters (0.1 Gyr < Age < 2 Gyr) and the age-metallicity relation for clusters within 6 Gyr are consistent with literature results. In order to fully study the chemical evolution history in the disk, more spectroscopic observations for old and distant open clusters are needed for further investigation.
