Short time domain coherent radio astronomy

短时域相干射电天文学

• 批准号: RGPIN-2019-06770
• 负责人: Pen, UeLi
• 金额: $ 2.48万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=746482
• 关键词: Short; time; domain; coherent; radio

This proposal builds on recent breakthroughs in Very Long Baseline Interferometry (VLBI) to study the changing radio universe on very short timescales. Research at short time scales, from a few nanoseconds to seconds, is important because many of the most pressing questions in astronomy concern difficult-to-study, fleeting phenomena. Our group recently innovated new algorithmic approaches to VLBI that now allow us to study signals in these very short time windows. The development of these new tools broadly impacts compact object astrophysics, gravitational wave physics, and cosmology. Potential pulsar and Fast Radio Burst (FRB) precision distances from plasma lensing open the window to the accurate localization of nanohertz gravitational wave sources, while FRB propagation probes the cosmic baryon content. This research is likely to connect and substantially impact previously weakly linked fields. We recently used our new technique to characterize an extreme plasma lensing effect around the Black Widow pulsar. Though this pulsar has been studied for 30 years, our group was the first to develop a framework to interpret its fleeting changes in brightness because no researcher previously had the tools to analyze this ephemeral phenomenon that lasts only a few milliseconds. The importance of this finding is that the plasma lensing effect functions as a magnifying glass that allows us to study deep space phenomena with previously unthinkable precision. We have demonstrated how we can use this effect to map the emission regions of a pulsar located 6,500 light years away with kilometre-level resolution. This unprecedented feat is equivalent to measuring the width of a hair on Mars from Earth. Improving our understanding of plasma lenses and their use to study short time domain phenomena will be the major focus of this program. Short-term objectives include: 1. Understanding Interstellar Lenses: Plasma lensing effects have the potential to revolutionize radio astronomy but their nature and geometry are unknown. We will use VLBI scintillometry to map plasma lenses in the interstellar medium. 2. Using Plasma Lenses as Telescopes: We will also use VLBI scintillometry to better explore the use of scattering screens as interstellar plasma lenses. 3. Using Lensing Effects to Study FRBs: The nature of FRBs is one of the most perplexing enigmas in astrophysics and a major front for research. We will use our technique to attain a systematic spatial localization of FRBs.

该提议建立在很长的基线干涉法（VLBI）中最近突破性的基础上，以研究不断变化的无线电宇宙在很短的时间范围内。从几纳秒到几秒钟，在短时间内进行的研究很重要，因为天文学中许多最紧迫的问题涉及难以研究，短暂的现象。我们的小组最近对VLBI进行了创新的新算法方法，现在使我们能够在这些短时间窗口中研究信号。这些新工具的开发广泛影响紧凑的物体天体物理学，引力波物理学和宇宙学。潜在的Pulsar和快速无线电爆发（FRB）从等离子体镜头的精度距离为纳米赫兹引力波源的准确定位打开了窗口，而FRB传播问题是宇宙baryon含量。这项研究可能会连接并实质上影响以前弱连接的领域。最近，我们使用新技术来表征黑寡妇Pulsar周围的极端等离子体镜头效应。尽管该脉冲星已经进行了30年的研究，但我们的小组是第一个开发一个框架来解释其亮度变化的框架，因为没有研究人员以前没有工具来分析这种短暂现象，只能持续几毫秒。这一发现的重要性在于，等离子体镜头效应是一种放大镜，使我们能够以先前不可思议的精度研究深空现象。我们已经证明了如何利用这种效果来绘制以千层次分辨率的6,500光年的脉冲星的发射区域。这种前所未有的壮举等同于测量地球火星上头发的宽度。提高我们对等离子体镜头的理解及其用于研究短期领域现象的使用将是该计划的主要重点。短期目标包括：1。了解星际镜头：等离子体镜头效应有可能改变射电天文学，但其性质和几何形状尚不清楚。我们将使用VLBI闪烁测定法来绘制星际介质中的等离子体镜头。 2。使用等离子体透镜作为望远镜：我们还将使用VLBI闪烁体来更好地探索散射屏幕作为星际等离子体镜片的使用。 3。使用镜头效应研究美联储：FRB的性质是天体物理学中最令人困惑的谜团之一，也是研究的主要阵线。我们将使用我们的技术来实现FRB的系统空间定位。