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.***

脉冲星的闪烁或强度变化可用于探测类似于太阳系的尺寸尺度上的星际介质。由于闪烁是由星际气体离子化成分中的密度变化散射散射引起的，因此对脉冲星闪烁的详细研究可产生有关星际气体结块的信息，它是否表现出湍流，以及如何启动和维持密度变化。这些问题对于理解我们星系的动态以及其他像我们这样的其他螺旋星系的动力至关重要。在上一个赠款期间，Daniel Stinebring博士发现，在动态光谱中已经注意到了数十年的纵横交错模式，在变革空间中具有更清晰的签名。现在，他的小组使用脉冲星的高动态范围观测值广泛研究了这种闪烁弧现象，主要是用Arecibo射电望远镜获得的。该新奖项进行的研究将使用Arecibo射电望远镜和其他大型望远镜的高敏性观察详细探讨这种现象。将充分探索详细的子结构，包括倒数subarcs，并确定其时间尺度和频率行为。这项工作的目的是将闪烁弧的详细观察与离子化的星体内介质中的湍流气体的物理特征联系起来。该研究计划将涉及本科生兴奋地探索新现象，并拼凑出更大的难题的一部分：如何散发出大规模的小规模气体，最终会散发出大规模的构成小规模的湍流，从而散发出来？通过与Stinebring博士及其合作者紧密合作，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，学生将对解决大型和复杂问题的能力充满信心。与美国和国外科学家合作，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的其他角色做好准备。***