3千秒差距以外45个疏散星团的成员确定
Membership Determination of 45 Open Clusters Beyond 3 kpc
浏览论文内容
中文总结 AI 辅助
该研究利用Gaia DR3天体测量数据，对45个日心距离超3千秒差距的疏散星团（含30个已知、15个新候选）采用概率性成员确定方法，提升了暗弱成员恢复能力，为遥远疏散星团研究提供基础。
中文摘要 AI 辅助
背景：疏散星团（OCs）是研究银盘结构与化学演化的基本示踪体。由于严重的场星污染，以及遥远、受遮蔽系统的测光完备度下降，可靠识别星团成员，尤其是主序星暗端成员，仍具挑战性。目的：我们旨在利用Gaia DR3天体测量数据，识别并表征日心距离d≳3千秒差距的遥远疏散星团候选体，重点提升高污染恒星场中暗弱候选成员的恢复能力。方法：我们应用基于Gaia DR3自行与视差的概率性成员确定方法。候选成员通过组合天体测量标准筛选，并利用径向密度分布进行空间滤波优化，测光数据作为一致性校验。对于受显著消光影响的星团，纳入2MASS的近红外测光以弥补光学数据的局限性。结果：我们分析了45个目标样本，包含30个先前已报道的疏散星团与15个新识别的候选体，全部位于d≳3千秒差距区域。该方法使天体测量分布更紧凑，并提升了数个系统中暗弱候选成员的恢复能力；但对于投影在银道面附近受消光最严重的星团，残留场星污染仍不可忽略。结论：Gaia DR3天体测量数据为遥远疏散星团候选体的探索性识别与一级表征提供了有效基础；专用近红外后续观测对高消光区域的可靠成员评估至关重要。
英文摘要
Context. Open clusters (OCs) are fundamental tracers for studying the structure and chemical evolution of the Galactic disc. Reliable identification of cluster members, particularly at the faint end of the main sequence, remains challenging owing to severe field-star contamination and the declining photometric completeness for distant, obscured systems. Aims. We aim to identify and characterise distant OC candidates at heliocentric distances $d \gtrsim 3$ kpc using Gaia DR3 astrometry, with emphasis on improving the recovery of faint candidate members in highly contaminated stellar fields. Methods. We apply a probabilistic membership method based on Gaia DR3 proper motions and parallaxes. Candidate members are selected through combined astrometric criteria and refined via spatial filtering using radial density profiles, with photometric data serving as a consistency check. For clusters affected by significant extinction, near-infrared photometry from 2MASS is incorporated to compensate for the limitations of optical data. Results. We analyse a sample of 45 targets, comprising 30 previously reported OCs and 15 newly identified candidates, all located at $d \gtrsim 3$ kpc. The method yields more compact astrometric distributions and improves the recovery of faint candidate members in several systems. However, residual field contamination remains non-negligible for the most obscured clusters projected against the Galactic plane. Conclusions. Gaia DR3 astrometry provides an effective basis for the exploratory identification and first-order characterisation of distant OC candidates. Dedicated near-infrared follow-up observations will be essential for robust membership assessment in high extincted regions.
发表机构
- School of Physics and Astronomy, China West Normal University（西华师范大学物理与天体研究院）
机构由 AI 辅助整理，请以论文原文为准。
