An External Calibrator for HI Observatories

HI 天文台的外部校准器

• 批准号: 1407646
• 负责人: Judd Bowman
• 金额: $ 6.9万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-15 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1407646&HistoricalAwards=false
• 关键词: External; Calibrator; HI; Observatories

An exciting and scientifically important frontier of modern astronomy is the push to understand the Epoch of Reionization (EoR), a time in the distant past when the first stars began to influence the material between galaxies. This era is also referred to as "Cosmic Dawn", and has been identified as potentially rife with new discoveries and one of the key problems to be understood in the near future. With that in mind, some innovative instrumentation has been under development, including new radio-astronomy arrays suchs as the Murchison Widefield Array (MWA) and the Precision Array for Probing the Epoch of Reionization (PAPER). The precise extraction of the needed information from such instruments requires unusual measures for instrument calibration, and this proposal addresses that need by building ECHO, a helicopter drone to carry a test transmitter over the telescope array and investigate its actual spatial response pattern to a very high precision.A key obstacle to extracting the information on astrophysical processes from data measured by the new generation of telescope arrays is the accurate removal of foreground emission due to extraneous sources unrelated to the EoR emission being sought. That foreground emission problem depends critically on an accurate knowledge of the as-built primary beam of each telescope in the array. Current techniques, such as beam modeling, are uncertain at the 20% level; this project intends to push that limit down to 1% for MWA and PAPER. The scientific payoff is potentially very large.The ECHO project will recruit and train undergraduates interested in electronics and field experiments, and will feature strong student involvement in many phases of design, construction, and testing.Funding for this project is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.

现代天文学的一个令人兴奋且科学上重要的边界是推动理解电离时代（EOR）的努力，这是遥远的过去，第一颗恒星开始影响星系之间的材料。 这个时代也称为“宇宙黎明”，并被确定为有新发现的可能性，也是在不久的将来要理解的关键问题之一。 考虑到这一点，一些创新的仪器正在开发中，包括新的放射媒介阵列，例如Murchison Widefield Array（MWA）和用于探测Reionization时代（论文）的精确阵列。 从此类仪器中精确提取所需信息需要进行仪器校准的异常措施，该提案通过构建Echo来解决需要解决的需要，这是一架直升机无人机，直升机在望远镜阵列上携带测试发射机，并调查其实际的空间响应模式，并将其高精度置于iS iS eforter rever eforter的关键障碍中，以使其在整个iS exproly resector上置于iS experione的障碍。由于与寻求EOR发射无关的无关来源而引起的排放。 该前景排放问题批评阵列中每个望远镜的原始光束的准确知识。 当前技术（例如梁建模）在20％的水平上不确定。该项目打算将MWA和纸的限制降至1％。 科学的回报可能非常大。回声项目将招募和培训对电子和现场实验感兴趣的大学生，并将通过其高级技术和仪器程序提供了由NSF的天文学科学部提供的该项目的许多阶段的学生参与。为该项目提供资金。