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arXiv 1701.04712astro-ph.GA
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SEDIGISM:银河系内部星际介质的结构、激发和动力学

SEDIGISM: Structure, excitation, and dynamics of the inner Galactic interstellar medium

F. Schuller, T. Csengeri, J. S. Urquhart, A. Duarte-Cabral, P. J. Barnes, A. Giannetti, A. K. Hernandez, S. Leurini, M. Mattern, S. -N. X. Medina, C. Agurto, F.… 展开作者

F. Schuller, T. Csengeri, J. S. Urquhart, A. Duarte-Cabral, P. J. Barnes, A. Giannetti, A. K. Hernandez, S. Leurini, M. Mattern, S. -N. X. Medina, C. Agurto, F. Azagra, L. D. Anderson, M. T. Beltrán, H. Beuther, S. Bontemps, L. Bronfman, C. L. Dobbs, M. Dumke, R. Finger, A. Ginsburg, E. Gonzalez, T. Henning, J. Kauffmann, F. Mac-Auliffe, K. M. Menten, F. M. Montenegro-Montes, T. J. T. Moore, E. Muller, R. Parra, J. -P. Perez-Beaupuits, A. Pettitt, D. Russeil, Á. Sánchez-Monge, P. Schilke, E. Schisano, S. Suri, L. Testi, K. Torstensson, P. Venegas, K. Wang, M. Wienen, F. Wyrowski, A. Zavagno

摘要:

尽管分子云对于理解星际介质的演化具有重要意义,但它们的起源和生命周期仍然没有得到很好的限制。我们对银河系内面进行了系统的、均匀的光谱测量,以补充许多连续的银河系测量,提供关键的距离和气体运动学信息。我们的目标是将这一数据集与最近的红外到亚毫米调查在类似的角分辨率。SEDIGISM巡天覆盖了13 CO在J=2-1旋转跃迁中的78度^2内星系(-60度<1 < +18度,|b| < 0.5度)。这种CO同位素的丰度比12 CO低100倍。因此,它的发射具有低到中等的光学深度和较高的临界密度,使其成为冷,致密星际介质的理想示踪剂。这些数据是用APEX的SHFI单像素仪器观测的。观测装置涵盖了13 CO(2-1)和C18 O(2-1)谱线,以及其他分子的几个跃迁。观察已经完成。数据缩减工作正在进行中,最后数据产品将在不久的将来提供。在这里,我们给出了调查和专用数据简化管道的详细描述。本文给出了一个覆盖-20 ° <1 < -18.5 °的科学示范场的初步结果。在这个领域的13 CO(2-1)数据的分析显示,在一个范围内的日心距离紧凑的团块,弥漫的云,和对流结构。通过结合我们的数据与数据在(1-0)过渡的CO同位素从ThrUMMS调查,我们能够计算三维实现的激发温度和光学深度的星际介质。最终,这次巡天将以前所未有的~30”的角分辨率提供银河系内部星际介质的详细全球视图。

英文摘要:

The origin and life-cycle of molecular clouds are still poorly constrained, despite their importance for understanding the evolution of the interstellar medium. We have carried out a systematic, homogeneous, spectroscopic survey of the inner Galactic plane, in order to complement the many continuum Galactic surveys available with crucial distance and gas-kinematic information. Our aim is to combine this data set with recent infrared to sub-millimetre surveys at similar angular resolutions. The SEDIGISM survey covers 78 deg^2 of the inner Galaxy (-60 deg < l < +18 deg, |b| < 0.5 deg) in the J=2-1 rotational transition of 13CO. This isotopologue of CO is less abundant than 12CO by factors up to 100. Therefore, its emission has low to moderate optical depths, and higher critical density, making it an ideal tracer of the cold, dense interstellar medium. The data have been observed with the SHFI single-pixel instrument at APEX. The observational setup covers the 13CO(2-1) and C18O(2-1) lines, plus several transitions from other molecules. The observations have been completed. Data reduction is in progress, and the final data products will be made available in the near future. Here we give a detailed description of the survey and the dedicated data reduction pipeline. Preliminary results based on a science demonstration field covering -20 deg < l < -18.5 deg are presented. Analysis of the 13CO(2-1) data in this field reveals compact clumps, diffuse clouds, and filamentary structures at a range of heliocentric distances. By combining our data with data in the (1-0) transition of CO isotopologues from the ThrUMMS survey, we are able to compute a 3D realization of the excitation temperature and optical depth in the interstellar medium. Ultimately, this survey will provide a detailed, global view of the inner Galactic interstellar medium at an unprecedented angular resolution of ~30".

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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