Release and Analysis of the Galactic Ring Survey

银河环调查的发布和分析

• 批准号: 0507657
• 负责人: James Jackson
• 金额: $ 52.5万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0507657&HistoricalAwards=false
• 关键词: Release; Analysis; Galactic; Ring; Survey

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.

AST 0507657杰克逊银河系的主要恒星形成结构，5千秒差距环，仍然在很大程度上未被探索。毫米波阵列技术的新进展允许对5 kpc环进行新的检查。利用FCRAO 14米望远镜上新的SEQUOIA多像素阵列接收器，詹姆斯杰克逊博士和同事正在进行一项新的内星系分子线调查，波士顿大学五学院射电天文台银河系环调查（GRS）。GRS是一项雄心勃勃的巡天计划，旨在绘制银河系内部，特别是13 CO中的5 kpc环。当数据采集在2005年4月完成时，他们将绘制出超过72平方度的内星系。 他们已经建立了有效的映射策略，自动化数据简化，并开始进行科学分析。 该奖项将用于准备和向社区发布数据，并进行科学调查。GRS的一个特别令人兴奋的发现是发现了红外暗云，它们是大质量恒星形成区的冷而致密的前兆。与以前的银河系内部分子线调查相比，GRS提供了极好的灵敏度（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”）以及使用比12 CO更好的柱密度示踪剂13 CO（1-0）。所有GRS数据都将提供给天文学界。通过使用13 CO最大限度地减少速度拥挤，他们可以分离，识别和编目整个5 kpc环的分子云和云核。由于22”的采样率非常精细，它们将更好地确定这些云的结构。此外，他们还发现，21厘米高的自我吸收功能，对GRS分子云允许解决长期存在的近/远kinematicdistance模糊。因为他们可以测量到云的距离和嵌入云的红外年轻恒星和星星团，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。 他们将在这段资助期内完成五项重要的科学计划：o为天文台发现的分子云及云核编制目录o确定分子云及其内藏的红外恒星形成区的运动距离o确定银河系内部的结构，特别是5千秒差距环的结构o量化及测试分子云内部结构的模型o探测红外暗云的内部结构，以研究星团形成的最早阶段。由于GRS团队将由博士后，研究生和本科生组成，GRS将帮助培养下一代天文学家和程序员。在今后20年内，无论是在灵敏度还是面积覆盖方面都不太可能超过地球观测卫星，因为用计划中的一套新的大口径单碟望远镜或干涉仪进行大面积勘测在技术上是不可行的。就像帕洛玛巡天和斯隆巡天一样，GRS将是银河系天文学家世代不可或缺的独特资源。它的13 CO全景图将成为未来大量银河系研究的发现图。