RUI: Pulsars and the Interstellar Medium

RUI：脉冲星和星际介质

• 批准号: 9619493
• 负责人: Dan Stinebring
• 金额: $ 14.77万
• 依托单位: Oberlin College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-15 至 2001-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9619493&HistoricalAwards=false
• 关键词: RUI; Pulsars; Interstellar; Medium

Abstract Stinebring Turbulence in the interstellar medium provides the support needed to keep the gas from collapsing into a pancake. Evidence from pulsar observations indicates that a turbulent cascade of energy may exist over 12 orders of magnitude in scale size from 10 to the eighth (one hundred million) cm to 100 parsec. This turbulent cascade is not well understood, although high mass stars probably account for much of the energy input to the cascade through stellar winds, ionization, and supernova explosions. In particular, the dissipation of turbulent energy into heat at some scale size less than 10 to the tenth (ten billion) cm must occur, but the details of the mechanism and the physical conditions under which this happens are sketchy. The research to be carried out is aimed at determining the strength of the turbulent cascade at a size scale around 10 to the tenth cm and smaller and to learn more about the dissipation mechanism. The main technique employed will be the observational study of radio pulsar scintillation in the weak scattering regime. This is an opportune time to embark on such a study since both the upgraded Arecibo, Puerto Rico telescope and the soon-to-be-completed Green Bank Telescope will provide outstanding opportunities for pulsar observations above 1 GHz. This is the frequency range in which weak scattering phenomena can be studied effectively. The phenomenon of image-splitting, in which the pulsar image separates into two or more distinct pieces due to scattering in the transition regime between strong and weak scattering, will also be explored. The goals are the same: to better elucidate the strength of the electron inhomogeneity spectrum in the Galaxy and to seek evidence for a dissipation scale. High time resolution studies of bright pulsars will also be undertaken using a well-known VLBI recording system, the S2 system, to obtain baseband sampled data. These observations, which can be conducted at several observat ories (and observing frequencies) simultaneously, will allow high-precision monitoring of pulsar dispersion measures. This provides additional information about the electron inhomogeneities in the Galaxy. As a secondary effort, the baseband sampled data will also be analyzed to study brief and intense radio emission from pulsars in order to better understand the emission physics. Undergraduate students from Oberlin College will be centrally involved in all of these projects and will participate in observations, analysis, and the presentation of the results.

抽象的Stinebring 星际介质中的湍流提供了必要的支持，以防止气体坍缩成煎饼。 来自脉冲星观测的证据表明，湍流能量级联可能存在12个数量级以上的尺度，从10到八分之一（一亿）厘米到100秒差距。这种湍流级联还没有得到很好的理解，尽管大质量恒星可能通过恒星风，电离和超新星爆炸占级联能量输入的大部分。 特别是，在小于10的10次方厘米（100亿厘米）的尺度上，湍流能量耗散成热是必然发生的，但其机制的细节和发生这种情况的物理条件尚不清楚。 将要进行的研究旨在确定10至10厘米或更小尺度的湍流级联的强度，并更多地了解耗散机制。 所采用的主要技术将是对弱散射区的射电脉冲星闪烁进行观测研究。 这是一个进行这种研究的适当时机，因为升级后的阿雷西博、波多黎各望远镜和即将完成的绿色岸望远镜都将为1千兆赫以上的脉冲星观测提供极好的机会。 这是可以有效研究弱散射现象的频率范围。 图像分裂的现象，其中脉冲星图像分离成两个或多个不同的部分，由于在强散射和弱散射之间的过渡制度的散射，也将进行探讨。目标是一样的：以更好地阐明银河系中电子不均匀性谱的强度，并寻求耗散尺度的证据。 还将利用著名的VLBI记录系统S2系统对明亮的双星进行高时间分辨率研究，以获得基带取样数据。 这些观测可以在几个观测站（和观测频率）同时进行，将允许对脉冲星色散测量进行高精度监测。 这提供了关于银河系中电子不均匀性的额外信息。作为第二项工作，还将分析基带采样数据，以研究来自恒星的短暂和强烈的无线电发射，以便更好地了解发射物理学。 来自奥伯林学院的本科生将集中参与所有这些项目，并将参与观察，分析和结果的演示。