Release and Analysis of the Galactic Ring Survey

银河系主要的恒星形成结构，5kpc环，在很大程度上仍未被探索。毫米波阵列技术的新进展允许对5kpc环进行新的检查。利用FCRAO 14米望远镜上的新型SEQUOIA多像素阵列接收器，James Jackson博士和他的同事们正在对银河系内部进行一项新的分子线调查，即波士顿大学-五学院射电天文台银河系环调查（GRS）。GRS是一项雄心勃勃的调查，旨在绘制银河系内部，特别是13CO年的5kpc环。当数据采集于2005年4月完成时，他们将绘制出内星系72平方度的地图。他们建立了有效的制图策略，自动化了数据缩减，并开始了科学分析。这笔奖金将用于准备和向社区发布数据并进行科学调查。一个特别令人兴奋的GRS发现是红外黑云的识别，它是大质量恒星形成区域的寒冷、密集的前体。与之前对银河系内部的分子线调查相比，GRS具有出色的灵敏度（0.4 K），更好的光谱分辨率（0.21 km/s），相同或更好的角分辨率（46”），更好的采样（22”），并且使用了13CO(1-0)，这是一种比12CO更好的柱密度示光剂。所有GRS数据将提供给天文学界。通过使用13CO最小化速度拥挤，他们可以在整个5kpc环中隔离、识别和编目分子云和云核。因为22英寸的采样率非常好，他们将更好地确定这些云的结构。此外，他们还发现21cm H I对GRS分子云的自吸收特征允许人们解决长期存在的近/远运动距离模糊问题。因为他们可以测量到云及其内嵌的红外年轻恒星物体和星团的距离，他们可以第一次确定它们的质量、大小、分布和光度。通过新的MSX和斯皮策红外巡天，研究小组可以确定整个银河系内部嵌入的年轻恒星物体的光度、距离和分布。他们将在资助期内完成五项重点科研项目：o分子云和GRS发现的云核编目。o建立分子云及其内嵌红外恒星形成区域的运动距离。确定银河系内部的结构，特别是5kpc环的结构。o对分子云内部结构的模型进行量化和测试。o探测红外乌云的内部结构，以研究星团形成的最早阶段。在2005年完成后，GRS将成为内星系分子气体分布的最终地图。由于GRS团队将由博士后、研究生和本科生组成，因此GRS将帮助培养下一代天文学家和程序员。在未来的20年里，GRS在灵敏度和覆盖面积上都不太可能被超越，因为用新计划的大口径单碟望远镜或干涉仪进行大面积调查在技术上是不可行的。就像帕洛玛巡天和斯隆巡天一样，GRS将成为几代银河系天文学家的重要而独特的资源。它的全景13CO地图将成为未来大量银河系研究的发现图表。

AST 0507657JacksonThe Milky Way's dominant star-forming structure, the 5 kpc ring, remains largely unexplored. New advances in mm-wave array technology permit a fresh examination of the 5 kpc ring. Using the new SEQUOIA multipixel array receiver on the FCRAO 14 m telescope, Dr. James Jackson and colleagues are conducting a new molecular line survey of the inner Galaxy, the Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey (GRS). The GRS is an ambitious survey designed to map the inner Galaxy and especially the 5 kpc ring in 13CO. When the data-taking is complete in April 2005, they will have mapped over 72 square degrees of the Inner Galaxy. They have established efficient mapping strategies, automated the data reduction, and begun the scientific analysis. This award will be used to prepare and release the data to the community and to conduct scientific investigations. A particularly exciting GRS discovery was the identification of Infrared Dark Clouds as the cold, dense precursors to massive star-forming regions.Compared with previous molecular line surveys of the inner Galaxy, the GRS offers excellent sensitivity (0.4 K), better spectral resolution (0.21 km/s), the same or better angular resolution (46"), better sampling (22"), and the use of 13CO (1-0), a better column density tracer than 12CO. All GRS data will be made available to the astronomical community. By minimizing velocity-crowding through the use of 13CO, they can isolate, identify, and catalog molecular clouds and cloud cores throughout the 5 kpc ring. Because the 22" sampling rate is so fine, they will better determine the structures of these clouds. Moreover, they have found that 21 cm H I selfabsorptionfeatures toward GRS molecular clouds allow one to resolve the long-standing near/far kinematicdistance ambiguity. Because they can measure the distances to clouds and their embedded infrared young stellar objects and star clusters, they can for the first time establish their masses, sizes, distributions, and luminosities. With the new MSX and Spitzer infrared surveys, the research team can determine the luminosities, distances, and distribution of embedded young stellar objects throughout the inner Galaxy. They will complete five key science projects in this funding period:o Cataloging molecular clouds and cloud cores discovered by the GRS.o Establishing kinematic distances to molecular clouds and their embedded infrared star-formingregions.o Determining the structure of the inner Milky Way, and especially that of the 5 kpc ring.o Quantifying and testing models of the internal structure of molecular clouds.o Probing the internal structure of Infrared Dark Clouds to study the very earliest phases of clusterformation.When complete in 2005, the GRS will be the definitive map of the molecular gas distribution in the Inner Galaxy. Because the GRS team will consist of postdocs, graduate students, and undergraduates, the GRS will help train the next generation of astronomers and programmers. It is unlikely that the GRS will be surpassed in either sensitivity or areal coverage in the next 20 years, since it will be technically infeasible to conduct large-area surveys with the new suite of planned large-aperture single dish telescopes or interferometers. Like the Palomar and Sloan Surveys, the GRS will be a vital, unique resource for generations of Galactic astronomers. Its panoramic 13CO map will be the finding chart for an enormous amount of future Milky Way research.