RUI: Probing the Interstellar Medium Using Pulsar Scintillation

RUI：利用脉冲星闪烁探测星际介质

• 批准号: 0407302
• 负责人: Dan Stinebring
• 金额: $ 18.93万
• 依托单位: Oberlin College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0407302&HistoricalAwards=false
• 关键词: RUI; Probing; Interstellar; Medium; Using

The scintillation, or intensity variation, of pulsars can be used to probe the interstellar medium on size scales similar to that of the solar system. Since scintillation is caused by multi-path scattering off of density variations in the ionized component of the interstellar gas, a detailed study of pulsar scintillation yields information about how the interstellar gas is clumped, whether or not it exhibits turbulence, and how the density variations are initiated and sustained. These questions are central to an understanding of the dynamics of our galaxy and, hence, of other spiral galaxies like ours. During the previous grant period, Dr. Daniel Stinebring discovered that a crisscross pattern that had been noticed for decades in dynamic spectra has a much clearer signature in transform space. His group has now studied this scintillation arc phenomenon extensively, using high dynamic range observations of pulsars, primarily obtained with the Arecibo radio telescope. The research carried out with this new award will explore this phenomenon in detail using high-sensitivity observations from the Arecibo radio telescope and other large telescopes. Detailed substructure, including inverted subarcs, will be explored fully and their timescale and frequency behavior will be determined. The goal of this work is to connect the detailed observations of scintillation arcs with the physical characteristics of turbulent gas in the ionized interstellar medium.This research program will involve undergraduate students in the excitement of exploring a new phenomenon and piecing together parts of a bigger puzzle: how does large scale stirring of the interstellar gas create small scale turbulence which is eventually dissipated as heat? By working closely with Dr. Stinebring and his collaborators, the students will gain a broad range of technical skills as well as further develop their ability to independently explore problems. Using state-of-the-art electronics and computers at the largest radio telescopes in the world, the students will gain confidence in their ability to tackle large and complex problems. Opportunities to collaborate with scientists in the U.S. and abroad and to report their work at conferences and in publications will enhance students research experience and prepare them for graduate training or other roles in the technical workforce.***

恒星的闪烁或强度变化可以用来探测星际介质，其大小与太阳系相似。由于闪烁是由星际气体电离成分的密度变化的多路径散射引起的，因此对脉冲星闪烁的详细研究可以提供有关星际气体如何聚集的信息，它是否表现出湍流，以及密度变化是如何开始和维持的。这些问题对于理解我们银河系的动力学至关重要，因此也是理解像我们这样的其他螺旋星系的动力学的核心。在上一个资助期间，丹尼尔·斯泰纳布林博士发现，几十年来在动态光谱中被注意到的十字形图案在变换空间中有了更清晰的特征。他的小组现在已经广泛地研究了这种闪烁弧现象，使用主要由阿雷西博射电望远镜获得的高动态范围观测。这项新的研究将利用阿雷西博射电望远镜和其他大型望远镜的高灵敏度观测来详细探索这一现象。详细的子结构，包括倒置的子弧，将被充分探索，并确定其时间尺度和频率行为。这项工作的目标是将闪烁弧的详细观测与电离星际介质中湍流气体的物理特性联系起来。这项研究计划将使本科生兴奋地探索一种新现象，并将一个更大的谜团的各个部分拼凑起来：星际气体的大规模搅拌如何产生最终以热量形式消散的小规模湍流？通过与Stinebring博士及其合作者密切合作，学生将获得广泛的技术技能，并进一步发展他们独立探索问题的能力。在世界上最大的射电望远镜上使用最先进的电子设备和计算机，学生们将对自己解决大型复杂问题的能力充满信心。与美国和国外的科学家合作并在会议和出版物中报告他们的工作的机会将增强学生的研究经验，并为研究生培训或技术劳动力中的其他角色做好准备。