Collaborative Research: The Last of FIRST: Completing Our View of the Radio Universe

“ast - 009835a”是一个为期十年的项目，使用世界上最强大的射电望远镜提供20厘米处射电天空的清晰图像（First），该项目正在接近其绘制银河系以外整个北部天空的目标，其分辨率和灵敏度超过以往调查的50倍或更多。迄今为止，已经探测到超过75万个射电发射器，从附近的活跃恒星到已知的最遥远的类星体。这些图像和源目录都可以在万维网上找到，迄今已有300多名天文学家使用过。FIRST团队正在利用这个庞大的新数据库进行一些重大项目。他们将射电目录与2MASS巡天项目编目的近红外源相匹配，发现了许多高度模糊的类星体——这些星体从遥远星系核心的一个微小区域发射出的能量是整个银河系的1000倍，这个区域尘埃密布，没有可见光逃逸。另一个主要项目是利用整套无线电图像试图确定宇宙中神秘暗物质的分布。认识到爱因斯坦的“质量使光弯曲”这一格言后，他们开始寻找遥远的射电星系的形状上的轻微扭曲，这是由于射电星系的无线电波通过中间空间的质量分布造成的。虽然光学天文学家已经在满月大小或更小的天空斑块上进行了这种“弱透镜”实验，但这项研究将在10到100倍大的尺度上研究暗物质的块状，从而在局部宇宙中的星系分布和宇宙背景辐射中看到的波动之间建立直接联系，这些波动告诉我们最早时期物质的分布。

Collaborative Research: The Last of First: Completing Our View of the Radio Universe"AST-0098355A ten-year program to use the world's most powerful radio telescope to provideFaint Images of the Radio Sky at Twenty-cm (FIRST) is nearing its goal of mapping theentire northern sky outside the Milky Way with a resolution and sensitivity that exceed previous surveys by a factor of fifty or more. Over three-quarters ofa million radio emitters have been detected to date, ranging from nearby activestars to the most distant quasars known. The images and source catalogs are allavailable on the World-Wide Web, and have been used to date by more thanthree hundred astronomers.The FIRST team is pursuing a number of major projects with this massive newdatabase. Matching the radio catalog to the near-infrared sources catalogedby the 2MASS survey, they have discovered a number of highly obscured quasars --objects emitting a thousand times the energy of the whole Milky Way from a tinyregion in a distant galaxy core that is so dust-ridden that no visiblelight escapes. Another major project is using the entire set of radio images to attempt todetermine the distribution of the mysterious dark matter in the Universe.Recognizing Einstein's dictum that mass bends light, they look for the slightdistortions in the shapes of distant radio galaxies caused by the passage oftheir radio waves through the mass distribution of the intervening space.While optical astronomers have been conducting such "weak lensing" experimentson patches of sky the size of the full moon and smaller, this research will study theclumpiness of the dark matter on scales ten to one hundred times larger,thus making a direct connection between the galaxy distribution in the local Universe and the fluctuations seen in the cosmic background radiation whichtells us the distribution of matter at the earliest times.