How Bright is the Radio Sky? A 310 MHz Absolute Map

无线电天空有多亮？

• 批准号: 2307198
• 负责人: Jack Singal
• 金额: $ 58.99万
• 依托单位: University of Richmond
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307198&HistoricalAwards=false
• 关键词: How; Bright; Radio; Sky; 310

It is important to observe all of the light that comes to us from astronomical sources in the universe, including the kinds of light that human eyes cannot see, like the longer wavelength of light called radio waves.  In addition to the radio waves that come from bright objects in space that we know about, there is also diffuse radio emission which comes from every direction in the sky.  This diffuse radio emission can only be properly understood by observing it over large portions of the sky at different radio wavelengths.  This project will make a new, modern map of these signals by utilizing the unique features of the Robert C. Byrd Green Bank Telescope along with advanced custom instrumentation developed specifically for this project.  The investigators will leverage cutting-edge radio receiver technology and contemporary computing capabilities to achieve unprecedented accuracy.  The resulting picture of the radio emission coming from our universe will be available to the astronomical community as an important resource. This project will also provide essential direct training opportunities for researchers and students. This project will produce a new map of the absolute sky brightness at 310 MHz, with angular resolution finer than Galactic features as well as polarization information. The resulting map will be the first such large-scale, absolutely calibrated radio map to be made in 40 years and the only one ever where an absolute zero-level calibration is the primary goal.  This map of the whole sky north of -47 degrees declination, with all Galactic latitudes observed, will allow a determination, for the first time in a systematically reliable way, of the absolute level of diffuse radio emission in the universe and from Galactic structure.  It will provide an important new resource for understanding and constraining almost all Galactic and extragalactic phenomena that manifest in, or depend on the understanding of, diffuse radio emission. These include cosmic microwave background studies, 21-cm cosmology, cosmic ray propagation, magnetic field structures, supernova remnant and pulsar searches, composition of the interstellar medium, finer scale radio structure, tracers for Galactic phenomena at other wavelengths, investigations of the radio synchrotron background, and many more.  The investigators will deploy a custom, novel polarization-sensitive receiver and low sidelobe, high edge-taper feed on the Green Bank Telescope.  The novel receiver technologies that will be deployed and characterized have the potential to yield important applications in radio astronomy.  This project will provide essential direct training for postdoctoral researchers and undergraduate students, as well as many potential research opportunities for graduate students given the wide variety of astrophysical investigations it will enable.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

重要的是要观察来自宇宙中天文来源的所有光线，包括人眼看不到的光线，就像较长的波浪长度称为无线电波一样。除了我们所知道的空间中明亮物体的无线电波外，还有来自天空中各个方向的弥散无线电发射。只有通过在不同的无线电波长下在天空的大部分中观察到这种弥漫性无线电发射才能正确理解。该项目将利用Robert C. Byrd Green Bank望远镜的独特功能以及专门为该项目开发的高级自定义仪器，从而制作新的现代地图。研究人员将利用尖端的无线电接收器技术和当代计算功能来实现前所未有的准确性。从我们宇宙中产生的无线电排放的结果将作为重要资源提供给天文学界。该项目还将为研究人员和学生提供基本的直接培训机会。该项目将生成310 MHz的绝对天空亮度的新地图，其角度分辨率比银河系特征和极化信息更好。由此产生的地图将是第一个如此大规模的绝对校准的无线电图，是在40年内制作的，也是唯一一个绝对零级校准的是主要目标。这张整个天空的地图以-47度偏斜的北部北部的北方纬度（观察到了所有银河纬度），将首次以系统可靠的方式确定宇宙中弥漫性无线电发射的绝对水平和银河结构的绝对水平。它将提供一个重要的新资源，用于理解和控制几乎所有表现出或取决于对弥漫性无线电发射的理解的银河系和外层面现象。其中包括宇宙微波背景研究，21-CM宇宙学，宇宙射线传播，磁场结构，超新星残留和脉冲星搜索，星际介质的组成，较细的范围无线电结构，用于其他波长的银河现象的示踪剂，对无线电同步背景的研究以及更多。调查人员将在绿色银行望远镜上部署一种定制的，新颖的极化敏感接收器和低边缘式的高边缘式饲料。将要部署和表征的新型接收器技术有可能在射电天文学中产生重要的应用。该项目将为博士后研究人员和本科生提供基本的直接培训，以及鉴于将启用的各种天体物理投资的种类繁多的许多潜在的研究机会。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估来通过评估来获得支持的。