Milky Way中心千秒差距内广泛分布的热氨
Widespread Hot Ammonia in the Central Kiloparsec of the Milky Way
摘要：
银河系内部的300-500 pc具有我们银河系中最极端的气体条件。中心分子区（CMZ）的物理性质，包括温度、密度、热压力和湍流压力，是表征气体能量学、运动学和演化的关键因素。这个区域的分子气体比银河系盘中的气体热一个数量级以上，但加热气体的机制仍然不确定。我们表征的温度为16个区域，延伸到一个投影半径为$\sim$ 450 pc。利用澳大利亚望远镜紧凑阵（ATCA）观测到了SWAG（Survey of Water and Ammonia in Galactic Center）的\am，J，K=（1，1）-（6，6）反转跃迁，利用100 m格林班克望远镜观测到了氨谱线（J，K）=（8，8）-（14，14）.使用这两个样本，我们为每个源创建完整的玻尔兹曼图，并将两个旋转温度分量拟合到数据中。对于冷部件，我们检测到的旋转温度范围为20- 80 K，对于热部件，我们检测到的温度范围为210- 580 K。有了这个16个区域的样本，我们确定了迄今为止在银河系中心检测到的一些最极端的分子气体温度。我们没有发现气体温度和银心半径之间的相关性，我们证实，这些高温并不完全与积极的恒星形成云。我们还研究了温度和线宽，发现（1）温度和线宽之间没有相关性，（2）线是非热加宽的，表明非热运动是占主导地位的热。
英文摘要：
The inner 300-500 pc of the Milky Way has some of the most extreme gas conditions in our Galaxy. Physical properties of the Central Molecular Zone (CMZ), including temperature, density, thermal pressure, and turbulent pressure, are key factors for characterizing gas energetics, kinematics, and evolution. The molecular gas in this region is more than an order of magnitude hotter than gas in the Galactic disk, but the mechanism responsible for heating the gas remains uncertain. We characterize the temperature for 16 regions, extending out to a projected radius of $\sim$450 pc. We observe \am\, J,K=(1,1)-(6,6) inversion transitions from SWAG (Survey of Water and Ammonia in the Galactic Center) using the Australia Telescope Compact Array (ATCA), and ammonia lines (J,K) = (8,8)-(14,14) using the 100\,m Green Bank Telescope. Using these two samples we create full Boltzmann plots for every source and fit two rotational temperature components to the data. For the cool component we detect rotational temperatures ranging from 20-80\,K, and for the hot component we detect temperature ranging from 210-580\,K. With this sample of 16 regions, we identify some of the most extreme molecular gas temperatures detected in the Galactic center thus far. We do not find a correlation between gas temperature and Galactocentric radius, and we confirm that these high temperatures are not exclusively associated with actively star-forming clouds. We also investigate temperature and line widths and find (1) no correlation between temperature and line width and (2) the lines are non-thermally broadened indicating that non-thermal motions are dominant over thermal.
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。
