We present the detection of metastable inversion lines of ammonia from energy levels high above the ground state. We detect these lines in both emission and absorption toward fifteen of seventeen positions in the central 300 parsecs of the Galaxy. In total, we observe seven metastable transitions of ammonia: (8,8), (9,9), (10,10), (11,11), (12,12), (13,13) and (15,15), with energies (in Kelvins) ranging from 680 to 2200 K. We also map emission from ammonia (8,8) and (9,9) in two clouds in the Sgr A complex (M-0.02-0.07 and M-0.13-0.08), and we find that the line emission is concentrated toward the the dense centers of these molecular clouds. The rotational temperatures derived from the metastable lines toward M-0.02-0.07 and M-0.13-0.08 and an additional cloud (M0.25+0.01) range from 350 to 450 K. Similarly highly-excited lines of ammonia have previously been observed toward Sgr B2, where gas with kinetic temperatures of ~600 K has been inferred. Our observations show that the existence of a hot molecular gas component is not unique to Sgr B2, but rather appears common to many Galactic center molecular clouds. In M-0.02-0.07, we find that the hot ammonia, contributes ~10% of the cloud's total ammonia column density, and further, that the hot ammonia in this cloud arises in gas which is extended or uniformly distributed on ~10 arcsecond scales. We discuss the implications of these constraints upon the nature of this hot gas component. In addition to the detection of hot metastable ammonia line emission, we also detect for the first time emission from nonmetastable inversion transitions of ammonia in both M-0.02-0.07 and M-0.13-0.08.
Widespread Hot Ammonia in the Central Kiloparsec of the Milky Way
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。
Probing the All-sky Distribution of Soft X-ray Emission Associated with the Milky Way
Tokai National Higher Education and Research System, Nagoya University（东京大学高等教育与研究系统名古屋大学）；NASA/Marshall Space Flight Center（美国国家航空航天局/马歇尔太空飞行中心）；Tokyo University of Science（东京理科大学）；NASA/Goddard Space Flight Center（美国国家航空航天局/戈达德太空飞行中心）；LATMOS/IPSL, UVSQ Université Paris-Saclay, Sorbonne Université, CNRS（大气、气候和地球动力学实验室/IPSL，巴黎萨克雷大学UVSQ分校，索邦大学，法国国家科学研究中心）；The Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University（约翰斯·霍普金斯大学亨利·A·罗兰尔物理与天文学系）
Subarcsecond Multi-line Observations of NH$_3$ with VLA toward the Class 0 Source IRAS 16293-2422
The University of Tokyo（东京大学）；RIKEN Pioneering Research Institute（理化学研究所先导研究本部）；National Radio Astronomy Observatory（美国国家射电天文台）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯玻尔研究所）
Toward a global model of the interactions in low-lying states of methyl cyanide: rotational and rovibrational spectroscopy of the $v_4 = 1$ state and tentative interstellar detection of the $v_4 = v_8 = 1$ state in Sgr B2(N)
通过对新的和已有的乙腈分子转动光谱的分析，将低振动态及其相互作用的整体模型推广到$v_4=1$（920 cm $^{-1}$）.旋转光谱覆盖了36 $-$ 1439 GHz区域的大部分，并分别达到量子数$J$和$K$为79和16。CH $_3$ CN的$K$能级结构的信息由IR光谱获得。在我们以前的研究中分析的717 cm $^{-1}$周围的$2ν_8$光谱也覆盖了$ν_4$带。在这个波段的分配覆盖880 $-$ 952 cm $^{-1}$，获得的量子数$J$和$K$分别为61和13。$v_4=1$最重要的相互作用似乎是与$v_8=3$、$ΔK=0$、$Δl=+3$的相互作用，这是一种先前表征的非谐共振。我们报告了与$ΔK=-2$和$Δl=+1$，与$ΔK=-4$和$Δl=-1$，与$ΔK=-6$和$Δl=-3$相互作用的新分析;这四种类型的相互作用将$v_8=3$的所有$l$亚态能量连接到$v_4=1$。还分析了已知的$ΔK=-2$、$Δl=+1$与$v_7=1$的相互作用，并且改进了对$ΔK=+1$、$Δl=-2$和$ΔK=+3$、$Δl=0$与$v_8=2$的共振的研究，以及主要通过新的$v_8\le 2$旋转数据改进了连续状态与$v_8\le 3$之间的相互作用。基于转动跃迁频率和$ν_4+ν_8-ν_8$热带数据对$v_4=v_8=1$态进行了初步的单态分析。尽管$v…
