AI 中文总结
本研究应用SigMA算法完成猎户座恒星形成复合体的全面星团普查，划分出47个恒星群，发现更多年轻星族与新候选子结构，构建了猎户座高分辨率时空图，为研究其恒星形成历史奠定基础。
AI 中文摘要
精确天体测量巡天与现代聚类算法正协同改变我们对恒星形成区的认知。通过揭示比以往可探测到的丰富得多的子结构，它们为通过精确分辨和测定各亚群年龄来重建恒星形成历史铺平了道路。猎户座恒星形成复合体是太阳附近研究最充分的恒星育婴室，也是目前距离最近的正在形成大质量恒星的复合体。即便如此，对其子结构的全面表征，包括均匀年龄测绘和消光分析，仍未完成。在此，我们利用最新版本的SigMA算法给出了猎户座复合体最完整的恒星种群普查，并概述了我们对该算法所做的补充与改进，这些改进将其应用范围扩展到了距离超过300秒差距的区域。我们将猎户座复合体划分为47个共空间、共运动的恒星群，包含11996个可靠成员，年龄范围为1.5至25百万年。为评估每个群的统计稳健性，我们通过10次独立聚类重复推导了每个源的星团持续值和个体成员概率。我们的群成员与文献结果吻合良好，但SigMA算法始终能找到约2至3倍更多的成员。尤其，它比以往算法分辨出更多非常年轻的种群，如NGC 2024、猎户座RV星、B30、NGC 1977、NGC 2068和NGC 2071。除了恢复28个已知星团和3个先前被归类为子结构的群之外，我们还提出了猎户座恒星形成复合体的16个新的同代子结构候选体。这项工作构建了猎户座的新的高分辨率时间分辨图像，该时空图使我们能够将其恒星成分与周围的星际介质联系起来，并为未来详细分析其恒星形成历史铺平了道路。
英文摘要
Precise astrometric surveys and modern clustering algorithms are working in step to transform our view of star-forming regions. By revealing a much richer substructure than previously accessible, they pave the way for reconstructing star formation histories by accurately resolving and age-dating individual sub-populations. The Orion star-forming complex is the best-studied stellar nursery in the solar neighborhood and the nearest one currently forming massive stars. Even so, a comprehensive characterization of its substructure, including a homogeneous age mapping and extinction analysis, is still incomplete. Here, we present the most complete census of stellar populations across the Orion complex from the newest version of the SigMA algorithm and outline our additions and improvements to the algorithm that have extended its usage to distant (>300 pc) regions. We separate the Orion complex into 47 co-spatial and co-moving stellar groups comprising 11,996 reliable members, with ages ranging from 1.5 to 25 Myr. To evaluate the statistical robustness of each group, we derive cluster persistence values and individual membership probabilities for each source from 10 independent clustering repetitions. Our group memberships agree well with the literature, but SigMA consistently finds a factor of ~2-3 more members. In particular, it resolves more very young populations, such as NGC 2024, RV Orionis, B30, NGC 1977, NGC 2068, and NGC 2071, than previous algorithms. In addition to recovering 28 known clusters and three groups previously classified as substructures, we present 16 new co-eval substructure candidates of the Orion star-forming complex. This work builds up a new high-resolution time-resolved picture of Orion. This spatio-temporal map allows us to relate its stellar content to the surrounding ISM and paves the way for a detailed analysis of its star formation history in the future.
Comments14 pages, 10 figures, 6 pages appendix. Submitted to A&A. Comments welcome
