Collaborative Project: The Universe from 5 pc to z=5 with the FIRST Survey

合作项目：通过 FIRST 巡天从 5 pc 到 z=5 的宇宙

• 批准号: 9802732
• 负责人: David Helfand
• 金额: $ 29.34万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2002-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9802732&HistoricalAwards=false
• 关键词: Collaborative; Project; Universe; pc; z=5

AST-9802732 Helfand Dr. Helfand and Dr. Becker are collaborating to use the FIRST database. The FIRST (Faint Images of the Radio Sky at Twenty-one cm) survey covered 5000 square degrees of the northern sky. The FIRST data are publicly available as are the image database and source catalogs. The FIRST project provides to users a sophisticated catalog search engine and image cutout server. Nearly a quarter of a million hits to the database have been recorded since 1994. The FIRST catalog is now the largest catalog in the NASA Extragalactic Database. The team are undertaking four projects: (1) study of weak gravitational lensing, the angular correlation function, and the angular size-redshift distribution for double radio sources, (2) study of bent double radio sources as tracers, (3) a bright quasar survey along with BL Lacs, red quasars and gravitational lenses, (4) a study of radio stars and rapidly variable radio sources. These projects exploit the sensitivity, morphological fidelity and astrometric accuracy of the FIRST survey. The PI's are adding over 2000 quasars, 300 BL Lacs, and at least 10 lens systems during the course of the project. Bent-double radio galaxies derived from the FIRST survey can be used to select clusters with the efficiency to redshifts of 0.85 and beyond. Since the distorted radio lobes in these systems guarantee that the clusters contain a dense ICM, their sample is critical to understanding the evolution of the x-ray luminosity function in clusters. The PI's are also using the data from the FIRST catalog as a set of background images for which weak lensing effects of the total foreground mass distribution (dark matter plus light) reveals the true nature of large-scale structure on scales of 0.5 to 10 degrees. ***

AST-9802732 Helfand Helfand博士和Becker博士正在合作使用FIRST数据库。 第一次（21厘米射电天空的微弱图像）调查覆盖了北方天空的5000平方度。 FIRST数据是公开的，图像数据库和源目录也是公开的。 FIRST项目为用户提供了一个先进的目录搜索引擎和图像剪切服务器。 自1994年以来，该数据库记录了近25万次点击。 FIRST星表现在是NASA河外星系数据库中最大的星表。 该研究组正在进行四个项目：（1）弱引力透镜、角相关函数和双射电源的角尺寸-红移分布的研究;（2）弯曲双射电源作为示踪剂的研究;（3）沿BL拉克、红类星体和引力透镜的亮类星体巡天沿着;（4）射电星和快变射电源的研究。 这些项目利用了FIRST巡天的灵敏度、形态保真度和天体测量精度。 PI在项目过程中增加了2000多个类星体，300个BL拉克和至少10个透镜系统。 从FIRST巡天中得到的弯双射电星系可以用来选择红移效率为0.85或更高的星系团。 由于这些系统中的扭曲的射电瓣保证了星团包含密集的ICM，因此它们的样本对于理解星团中x射线光度函数的演化至关重要。 PI还使用FIRST星表的数据作为一组背景图像，其中总前景质量分布（暗物质加光）的弱透镜效应揭示了0.5至10度尺度上大尺度结构的真实性质。 ***