The SEDIGISM survey: First Data Release and overview of the Galactic structure
The SEDIGISM survey: First Data Release and overview of the Galactic structure
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DOI：
10.1093/mnras/staa2369
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发表时间：
2020-07
影响因子：
4.8
通讯作者：
F. Schuller;F. Schuller;J. Urquhart;T. Csengeri;T. Csengeri;D. Colombo;A. Duarte-Cabral;M. Mattern-M.
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文献类型：
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作者：
F. Schuller;F. Schuller;J. Urquhart;T. Csengeri;T. Csengeri;D. Colombo;A. Duarte-Cabral;M. Mattern-M.
SEDIGSM（内银河星际介质的结构、激发和动力学）调查使用 APEX 望远镜在 ℓ = −60° 和 +31° 之间的几个分子跃迁中绘制了银河平面 84 deg2 的地图，包括 13CO (2 – 1) 和 C18O (2 – 1)，从而探测了星际介质的中等密度 (∼103 cm−3) 成分。它的角分辨率为 30 角秒，在 0.25 km s−1 速度分辨率下典型的 1σ 灵敏度为 0.8–1.0 K，因此可以获取各种结构，从单个恒星形成团块到巨型分子云和复合体。覆盖范围包括银河系第一象限和第四象限的很大一部分，使我们能够限制冷分子气体在银河系内部的大规模分布。在本文中，我们提供了完整调查和所使用的数据缩减程序的最新概述。我们还评估这些数据的质量，并描述作为首次数据发布 (DR1) 的一部分公开提供的数据产品。我们提出了分子气体的综合图和位置速度图，并利用它们来研究分子气体与银河系大尺度结构特征（如旋臂、银河棒和银河中心）之间的相关性。我们发现大约 60% 的分子气体与旋臂相关，并且这些在衍生的星系中心分布中显示为强强度峰值。我们还发现了对应于银河系中心和著名的恒星形成复合体的特定经度处的强度峰值，表明 13CO 排放集中在少数复合体中，而不是沿着旋臂均匀分布。
The SEDIGISM (Structure, Excitation and Dynamics of the Inner Galactic Interstellar Medium) survey used the APEX telescope to map 84 deg2 of the Galactic plane between ℓ = −60° and +31° in several molecular transitions, including 13CO (2 – 1) and C18O (2 – 1), thus probing the moderately dense (∼103 cm−3) component of the interstellar medium. With an angular resolution of 30 arcsec and a typical 1σ sensitivity of 0.8–1.0 K at 0.25 km s−1 velocity resolution, it gives access to a wide range of structures, from individual star-forming clumps to giant molecular clouds and complexes. The coverage includes a good fraction of the first and fourth Galactic quadrants, allowing us to constrain the large-scale distribution of cold molecular gas in the inner Galaxy. In this paper, we provide an updated overview of the full survey and the data reduction procedures used. We also assess the quality of these data and describe the data products that are being made publicly available as part of this First Data Release (DR1). We present integrated maps and position–velocity maps of the molecular gas and use these to investigate the correlation between the molecular gas and the large-scale structural features of the Milky Way such as the spiral arms, Galactic bar and Galactic Centre. We find that approximately 60 per cent of the molecular gas is associated with the spiral arms and these appear as strong intensity peaks in the derived Galactocentric distribution. We also find strong peaks in intensity at specific longitudes that correspond to the Galactic Centre and well-known star-forming complexes, revealing that the 13CO emission is concentrated in a small number of complexes rather than evenly distributed along spiral arms.