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of measurement has been done before using intensity interferometry, but the technique has fallen out of favor and been superseded by so-called phase interferometers.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中使用望远镜，对于某些项目，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，每个月都无用。 例如，有许多用于测量宇宙射线进入地球大气层时引起的电磁辐射的强度和方向（Cherenkov辐射）。 由于这些信号非常虚弱，并且产生的光非常微弱，因此望远镜通常会闲置近三分之一的夜晚。 但是，在月球闪耀时，仍可以进行调查诸如附近恒星之类的更明亮物体的研究项目。 为了在“光明时间”中使用此类可用的望远镜，犹他大学的Stephan Lebohec博士计划在明亮的时间内将它们用作强度干涉仪，以测量恒星的直径。 在使用强度干涉指标之前已经进行了这种测量，但是该技术已经失利并被所谓的相干干涉仪取代。 相干涉测量法适用于红色和红外光具有更长波长的红色恒星。但是，对于像我们的黄色太阳以及较热和蓝色恒星强度干涉法的恒星的表现要好得多。 NSF的天文科学划分高级技术和仪器计划正在为Lebohec博士提供资金，以获取和开发在Cherenkov望远镜上进行的强度干涉测量所需的仪器。