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您选择的条件: Zhongmu Li
  • LISC Catalog of Open Clusters.III. 83 Newly found Galactic disk open clusters using Gaia EDR3

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: As groups of coeval stars born from the same molecular cloud, an Open cluster (OC) is an ideal laboratory for studying the structure and dynamical evolution of the Milky Way. The release of High-Precision Gaia Early Data Release 3 (Gaia EDR3) and modern machine-learning methods offer unprecedented opportunities to identify OCs. In this study, we extended conventional HDBSCAN (e-HDBSCAN) for searching for new OCs in Gaia EDR3. A pipeline was developed based on the parallel computing technique to blindly search for open clusters from Gaia EDR3 within Galactic latitudes $\left| b \right|$ $<$25 $^\circ$. As a result, we obtained 3787 star clusters, of which 83 new OCs were reported after cross-match and visual inspection. At the same time, the main star cluster parameters are estimated by colour-magnitude diagram fitting. The study significantly increases the sample size and physical parameters of open clusters in the catalogue of OCs. It shows the incompleteness of the census of OCs across our Galaxy.

  • Identify 46 New Open Clusters Candidates In Gaia EDR3 Using pyUPMASK and Random Forest Hybrid Method

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Open clusters (OCs) are regarded as tracers to understand stellar evolution theory and validate stellar models. In this study, we presented a robust approach to identifying OCs. A hybrid method of pyUPMASK and RF is first used to remove field stars and determine more reliable members. An identification model based on the RF algorithm built based on 3714 OC samples from Gaia DR2 and EDR3 is then applied to identify OC candidates. The OC candidates are obtained after isochrone fitting, the advanced stellar population synthesis (ASPS) model fitting, and visual inspection. Using the proposed approach, we revisited 868 candidates and preliminarily clustered them by the friends-of-friends algorithm in Gaia EDR3. Excluding the open clusters that have already been reported, we focused on the remaining 300 unknown candidates. From high to low fitting quality, these unrevealed candidates were further classified into Class A (59), Class B (21), and Class C (220), respectively. As a result, 46 new reliable open cluster candidates among classes A and B are identified after visual inspection.

  • LISC Catalog of Open Clusters.III. 83 Newly found Galactic disk open clusters using Gaia EDR3

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: As groups of coeval stars born from the same molecular cloud, an Open cluster (OC) is an ideal laboratory for studying the structure and dynamical evolution of the Milky Way. The release of High-Precision Gaia Early Data Release 3 (Gaia EDR3) and modern machine-learning methods offer unprecedented opportunities to identify OCs. In this study, we extended conventional HDBSCAN (e-HDBSCAN) for searching for new OCs in Gaia EDR3. A pipeline was developed based on the parallel computing technique to blindly search for open clusters from Gaia EDR3 within Galactic latitudes $\left| b \right|$ $<$25 $^\circ$. As a result, we obtained 3787 star clusters, of which 83 new OCs were reported after cross-match and visual inspection. At the same time, the main star cluster parameters are estimated by colour-magnitude diagram fitting. The study significantly increases the sample size and physical parameters of open clusters in the catalogue of OCs. It shows the incompleteness of the census of OCs across our Galaxy.