Probing molecular line emission across the massive Galactic star forming region W49 in an extragalactic context

在河外背景下探测穿过巨大银河系恒星形成区 W49 的分子线发射

• 批准号: 516405419
• 负责人: Professor Dr. Frank Bigiel
• 金额: --
• 依托单位: Department of Astronomy
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/516405419?language=en
• 关键词: Probing; molecular; line; emission; across

We propose a three-year PhD project that will provide a substantial contribution to our understanding of star formation and molecular clouds in the Milky Way. The project is embedded in the IRAM 30m telescope Large Program LEGO, a comprehensive 500h mm-wave survey providing extensive spectral line mapping data on a diverse sample of molecular clouds in the Milky Way and with a particular focus on helping to interpret data from a range of recent extragalactic surveys, which can only observe at much lower resolution. With the advent of the current generation of (sub)mm-telescopes such as ALMA and NOEMA, other galaxies are becoming the focus of such dedicated surveys, covering an increasingly diverse set of molecular lines and pushing to scales of individual molecular clouds. Hence, this is the ideal time to connect these two fields via the proposed in-depth study of molecular line emission across massive star-forming regions in the Milky Way. This project will set a benchmark for many future observations within the field. Our group has already published a pilot study on one of these sources (W49), and with these data, along with additional, new observations from our team with the APEX telescope, this represents a perfect opportunity for a high-impact PhD project exploiting the wealth of data on this source. The project will be broken down into the following three distinct work packages (WP) that have significant scientific potential for the PhD student: WP-1) studying the excitation of CO (as the most commonly observed molecular species within the mm-window) as a tracer of the physical conditions of the bulk molecular gas across W49; WP-2) using canonical line ratios as well as the full suite of lines across the 3mm and 1mm window to study their variation as a function of environment, which will place constraints on their diagnostic power as empirical probes of local e.g. density and temperature variations; WP-3) Conduct the first rigorous quantitative comparison of molecular line emission diagnostics within the Milky Way and nearby extragalactic systems. While these work packages represent the core of the project, the analysis will undoubtedly uncover many interesting results providing ample opportunity for the student to pursue follow-up observations and projects.

我们提出了一个为期三年的博士项目，该项目将为我们了解银河系中的恒星形成和分子云做出重大贡献。该项目嵌入在 IRAM 30m 望远镜大型计划 LEGO 中，这是一项全面的 500 小时毫米波勘测，提供银河系不同分子云样本的广泛谱线映射数据，并特别注重帮助解释一系列最近的河外勘测数据，这些数据只能以低得多的分辨率进行观测。随着当前一代（亚）毫米望远镜（例如 ALMA 和 NOEMA）的出现，其他星系正在成为此类专门调查的焦点，涵盖越来越多样化的分子谱线，并扩大到单个分子云的规模。因此，现在是通过对银河系大质量恒星形成区域的分子线发射进行深入研究来连接这两个领域的理想时机。该项目将为该领域未来的许多观察设定基准。我们的小组已经发表了对这些来源之一（W49）的试点研究，有了这些数据，再加上我们团队使用 APEX 望远镜进行的额外新观察，这为利用该来源的丰富数据进行高影响力的博士项目提供了绝佳的机会。该项目将分为以下三个不同的工作包 (WP)，这些工作包对博士生具有重大的科学潜力： WP-1) 研究 CO 的激发（作为毫米窗口内最常见的分子种类），作为 W49 中散装分子气体物理条件的示踪剂； WP-2）使用规范线比率以及跨 3mm 和 1mm 窗口的全套线来研究它们随环境变化的变化，这将限制它们作为局部（例如）的经验探针的诊断能力。密度和温度变化； WP-3) 对银河系和附近河外系统内的分子线发射诊断进行首次严格的定量比较。虽然这些工作包代表了项目的核心，但分析无疑会发现许多有趣的结果，为学生提供充足的机会进行后续观察和项目。