SGER: Prototype Test Bench for Stellar Intensity Interferometry with Atmospheric Cherenkov Gamma Ray Telescopes

SGER：使用大气切伦科夫伽马射线望远镜进行恒星强度干涉测量的原型测试台

• 批准号: 0808636
• 负责人: Tugdual Lebohec
• 金额: $ 5.56万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0808636&HistoricalAwards=false
• 关键词: SGER; Prototype; Test; Bench; Stellar

For the most part, astronomers prefer to use their telescopes during the dark of the moon and for some projects the moon adds so much background light that telescopes go unused every month for the eight to ten nights surrounding full moon. For example, there are arrays of telescopes used to measure the intensity and the direction of electromagnetic radiation (Cherenkov radiation) caused when cosmic rays enter the earth's atmosphere. Because these signals are very weak and the resulting light very faint, the telescopes typically sit idle nearly a third of the nights. However, research projects that investigate brighter objects like nearby stars can still be conducted while the moon is shining. In order to make use of such available telescopes during "bright time," Dr. Stephan LeBohec of the University of Utah is planning to use them during bright time as an intensity interferometer to measure the diameters of stars. This kind of measurement has been done before using intensity interferometry, but the technique has fallen out of favor and been superseded by so-called phase interferometers. Phase interferometry works well for cooler, red stars where the red and infrared light has longer wavelengths. However, for stars like our yellow sun as well as for hotter and bluer stars intensity interferometry performs much better. NSF's Division of Astronomical Sciences Advanced Technologies and Instrumentation Program is providing funding for Dr. LeBohec to acquire and develop the instrumentation necessary for the intensity interferometry measurements to be made on the Cherenkov telescopes.

在大多数情况下，天文学家更喜欢在月球黑暗的时候使用望远镜，对于一些项目来说，月球增加了如此多的背景光，以至于望远镜在满月周围的八到十个晚上都没有使用。 例如，有望远镜阵列用于测量宇宙射线进入地球大气层时产生的电磁辐射（切伦科夫辐射）的强度和方向。 由于这些信号非常微弱，产生的光也非常微弱，望远镜通常有近三分之一的夜晚处于闲置状态。 然而，研究更明亮的物体（如附近的恒星）的研究项目仍然可以在月球闪耀时进行。 为了在“亮时”利用这些可用的望远镜，犹他州大学的Stephan LeBohec博士计划在亮时使用它们作为强度干涉仪来测量恒星的直径。 这种测量在使用强度干涉测量之前已经完成，但是该技术已经失宠并被所谓的相位干涉仪所取代。 相位干涉法适用于温度较低的红色恒星，那里的红光和红外光具有较长的波长。然而，对于像我们的黄色太阳这样的恒星，以及更热和更蓝的恒星，强度干涉测量法表现得更好。 NSF的天文科学部先进技术和仪器计划正在为LeBohec博士提供资金，以获得和开发在切伦科夫望远镜上进行强度干涉测量所需的仪器。