Real-Time Survey for Rapid Source Variability in Astronomical Objects using the Very Large Array

使用甚大阵列实时测量天文物体的快速源变化

• 批准号: 1611606
• 负责人: Casey Law
• 金额: $ 140.46万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611606&HistoricalAwards=false
• 关键词: Real; Time; Survey; Rapid; Source

The study of sources showing rapidly time variability is one of last frontiers of astronomy. This covers a wide range of wavelengths. In the radio range, variations had been found for our Sun in the 1940s. In the 1960s, slow time variations of astronomical sources were discovered. Later, radio sources emitting regular pulses were found. In the last few years, non-repeating, bursting sources have been found. One group of the most energetic radio sources is Fast Radio Bursts, or FRBs. FRBs are a rare phenomenon. The study of FRBs is a new one, and their distance and exact location is an open question. If the FRBs are located in other galaxies, the energy of such outbursts would reach the limits of possible emission mechanisms. The appeal of transient phenomena should provide wide public interest. There will be student in topics such as time variable astrophysics, high performance computing and efficient algorithms. This project will construct a system to search for transient phenomena during scheduled imaging observations made with the Very Large Array (VLA). Images are produced from the average of data over many hours. However, the evidence for rapid variations is lost in the averaging process. This project will construct a system designed to search the data for variability on time scales from 50 milliseconds to minutes, in parallel with scheduled astronomical programs. These searches will be carried out in real time. With the real-time system, only those samples showing significant bursts of radio energy would be stored. This system will be in use at all times when standard scientific programs are carried out, that is, a commensal system. In this, the data stream from the VLA will be searched for significant, short term bursts of radio energy with a powerful, especially designed system. This will not affect the normal scientific observations made with the VLA. The VLA can easily provide FRB positions that have errors smaller than 1 arc second, allowing optical identifications. This system will take advantage of the large amount of observing time available at the VLA, including the 6000 hours to be allocated to the already-planned VLA Sky Survey. This project is a precursor for larger facilities planned for the future, such as the Square Kilometer Array. There will be many opportunities for student training in the algorithms used to search for transient events in large data sets, and there will be outreach at the website of the National Radio Astronomy Observatory.

对显示出快速时间变化的源的研究是天文学最后的前沿领域之一。这涵盖了广泛的波长范围。在射电范围内，我们的太阳在20世纪40年代就发现了变化。在1960年代，天文源的慢时间变化被发现。后来，人们发现了发射规则脉冲的射电源。在过去的几年里，人们发现了不重复的爆发源。其中一组能量最大的射电源是快速射电爆发（FRB）。FRB是罕见的现象。FRB的研究是一个新的课题，其距离和确切位置是一个悬而未决的问题。如果FRB位于其他星系中，这种爆发的能量将达到可能的发射机制的极限。瞬态现象的吸引力应该引起广泛的公众兴趣。将有学生在主题，如时变天体物理学，高性能计算和高效算法。该项目将建立一个系统，在超大阵列（VLA）预定的成像观测期间搜索瞬态现象。图像是由多个小时的数据平均值生成的。然而，在平均过程中，快速变化的证据丢失了。该项目将建立一个系统，旨在搜索数据的变化时间尺度从50毫秒到分钟，与预定的天文计划并行。这些搜索将以真实的时间进行。在实时系统中，只有那些显示出显著的无线电能量爆发的样本才会被存储。在执行标准科学计划时，该系统将一直使用，即，一个系统。在这种情况下，来自VLA的数据流将通过一个强大的、专门设计的系统来搜索重要的、短期的无线电能量突发。这不会影响VLA的正常科学观测。VLA可以很容易地提供误差小于1弧秒的FRB位置，允许光学识别。该系统将利用VLA的大量观测时间，包括分配给已经计划的VLA巡天的6000小时。该项目是未来计划的更大设施的先驱，如平方公里阵列。将有许多机会对学生进行在大型数据集中搜索瞬变事件所用算法方面的培训，并将在国家射电天文学观测台的网站上开展外联活动。