Galactic Cold Interstellar Filaments: Structure, Kinematics, and Chemistry

银河冷星际丝：结构、运动学和化学

• 批准号: 263084949
• 负责人: Dr. Ke Wang
• 金额: --
• 依托单位: Europäische Südliche Sternwarte (ESO)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/263084949?language=en
• 关键词: Galactic; Cold; Interstellar; Filaments; Structure

Molecular interstellar medium is known to be highly hierarchical and filamentary. Studies in recent years have demonstrated the importance of filaments in star formation, at scales of <10 pc and >100 pc, and suggest a new paradigm for star formation. However, extremely filamentary giant molecular clouds (GMCs) at scales between 10 and 100 pc have not been studied systematically. A compelling sample does not exist at the first place, due to a historical limitation in the identifying methodology (i.e., extinction). In this project, we use the full Hi-GAL images to directly search for large filaments in the entire Galactic plane. We select a sample of 9 most prominent filaments with a length of 30-103 pc and mass (2.4-19)x10^4 Msun. The filaments are cold compared to surroundings and show no significant internal heating. This makes our project unique in probing the early evolutionary phases to study the connection of filamentary GMCs to the onset of star formation. We propose to perform a first systematic characterization of these filaments focusing on their hierarchical structure, kinematics, and core chemistry, aiming to reveal a comprehensive picture of high-mass star formation in the context of large filaments. The methods are designed so that results are directly comparable to numerical simulations and theoretical predictions. This is a timely project making use of the newly available Hi-GAL data, and will fill the gap between Galactic and local filaments, towards an understanding of filaments at all spatial scales.

已知分子星际介质是高度分层和丝状的。近年来的研究证明了细丝在<10 pc和>100 pc尺度的恒星形成中的重要性，并提出了恒星形成的新范式。然而，尺度在 10 到 100 pc 之间的极其丝状的巨分子云 (GMC) 尚未得到系统研究。由于识别方法的历史限制（即灭绝），令人信服的样本一开始就不存在。在这个项目中，我们使用完整的 Hi-GAL 图像来直接搜索整个银河平面中的大型细丝。我们选择了 9 个最突出的细丝样本，长度为 30-103 pc，质量为 (2.4-19)x10^4 Msun。与周围环境相比，灯丝很冷，并且没有显示出明显的内部加热。这使得我们的项目在探索早期进化阶段以研究丝状 GMC 与恒星形成开始之间的联系方面具有独特性。我们建议对这些细丝进行首次系统表征，重点关注它们的层次结构、运动学和核心化学，旨在揭示大细丝背景下高质量恒星形成的全面图景。这些方法的设计使得结果可以直接与数值模拟和理论预测进行比较。这是一个及时的项目，利用了新获得的 Hi-GAL 数据，并将填补银河和本地细丝之间的空白，以了解所有空间尺度的细丝。