First Results of an ALMA Band 10 Spectral Line Survey of NGC 6334I: Detections of Glycolaldehyde (HC(O)CH2OH) and a New Compact Bipolar Outflow in HDO and CS
First Results of an ALMA Band 10 Spectral Line Survey of NGC 6334I: Detections of Glycolaldehyde (HC(O)CH2OH) and a New Compact Bipolar Outflow in HDO and CS
复制标题
NGC 6334I 的 ALMA Band 10 谱线测量的初步结果：检测到乙醇醛 (HC(O)CH2OH) 以及 HDO 和 CS 中的新型紧凑双极流出
作者：
B. McGuire;C. Brogan;T. Hunter;A. Remijan;G. Blake;A. Burkhardt;P. B. Carroll;E. V. van Dishoeck;R. Garrod;H. Linnartz;C. Shingledecker;E. Willis
我们提出的第一个试点计划进行阿塔卡马大毫米波阵列（阿尔马）波段10光谱线调查的高质量恒星形成区域NGC 6334 I的结果。观测是在特殊的天气条件下进行的（0.19 mm可降水量），典型的系统温度Tsys < 950 K，频率为10890 GHz。在HDO和CS发射中可以看到明亮的南北两极外流，由嵌入的大质量原恒星MM 1B驱动。这使得，第一次，直接比较的热水在这个流出的水脉泽发射的位置从以前的22 GHz甚大阵列观测。微波激射器的位置被示出为对应于沿着流出腔壁的位置，在那里高速气体冲击周围的材料。我们还将我们的新观测结果与之前的Herschel外差仪器的远红外（HIFI）光谱线调查数据进行了比较，在阿塔卡马大型毫米/亚毫米阵列（阿尔马）数据中检测到一个数量级的光谱线（695与65）。我们专注于在阿尔马数据中检测到的复杂的有机分子乙醇醛（HC（O）CH 2 OH）的强检测，而在严重的光束稀释的HIFI光谱中没有检测到。最后，我们强调需要专门的太赫兹实验室光谱，以支持和利用未来的高频分子线观测与阿尔马。
We present the first results of a pilot program to conduct an Atacama Large Millimeter Array (ALMA) band 10 spectral line survey of the high-mass star-forming region NGC 6334I. The observations were taken in exceptional weather conditions (0.19 mm precipitable water) with typical system temperatures Tsys < 950 K at ∼890 GHz. A bright, bipolar north–south outflow is seen in HDO and CS emission, driven by the embedded massive protostar MM1B. This has allowed, for the first time, a direct comparison of the thermal water in this outflow to the location of water maser emission from prior 22 GHz Very Large Array observations. The maser locations are shown to correspond to the sites along the outflow cavity walls, where high-velocity gas impacts the surrounding material. We also compare our new observations to prior Herschel Heterodyne Instrument for the Far-infrared (HIFI) spectral line survey data of this field, detecting an order of magnitude more spectral lines (695 versus 65) in the Atacama Large Millimeter/submillimeter Array (ALMA) data. We focus on the strong detections of the complex organic molecule glycolaldehyde (HC(O)CH2OH) in the ALMA data that is not detected in the heavily beam-diluted HIFI spectra. Finally, we stress the need for dedicated THz laboratory spectroscopy to support and exploit future high-frequency molecular line observations with ALMA.