RUI: Radio Astronomical Investigations of the Interstellar Medium, Relativistic Gravitation, and Pulsars

RUI：星际介质、相对论引力和脉冲星的射电天文研究

• 批准号: 0807556
• 负责人: Joel Weisberg
• 金额: $ 33.23万
• 依托单位: Carleton College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-15 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0807556&HistoricalAwards=false
• 关键词: RUI; Radio; Astronomical; Investigations; Interstellar

Here, Dr. Weisberg will undertake a radioastronomical research program encompassing three major themes. The first two use pulsars as tools for the study of other physical phenomena - namely the interstellar medium and relativistic gravitation. The third focuses on studying the emissions and evolution of pulsars themselves.Pulsars possess several unique properties that make them ideal probes of the interstellar medium. Specifically, their emissions are pulsed, polarized, and pointlike. Their pulsing allows for dispersion delays to be measured, which leads to interstellar electron density determinations. Their high polarization permits the measurement of Faraday rotation, which yields galactic magnetic field measurements along the line of sight. That they are pointlike ensures that the signal probes a needle-thin column along the line of sight. In this part of the project, five principal spectrometric and polarimetric investigations will be undertaken that take advantage of these three properties to advance the understanding of a wide variety of phenomena in the interstellar medium, including the characteristics of neutral atomic, molecular, and ionized regions, especially on the smallest scales The first binary pulsar, PSR B1913+16, has proved to be an outstanding laboratory for the study of relativistic gravitation. Although the accuracy of probing gravity wave emission is now limited by systematic effects, there are still new and interesting relativistic phenomena that will be studied here. The 'Shapiro' gravitational propagation delay is expected to become measurable over the next decade, which will lead to two additional relativistic tests which can constrain otherwise viable gravitational theories. The 'geodetic' spin axis precession causes the line of sight to slowly drift across the pulsar, thereby permitting a rare glimpse of the emission beam in the direction orthogonal to its usual presentation. The additional observations which are supported here will uniquely help to further constrain the beam shape, a basic quantity that will be useful for emission mechanism studies. The details of the pulsar emission mechanism and of the nature of pulsar interiors are still unclear forty years after the discovery of these objects. A series of experiments to measure their polarized emissions will be carried out by Dr. Weisberg and students with an eye toward establishing the beam geometry, and studying and creating empirical emission models. The observations will be carried out with the Arecibo, Green Bank, and Parkes telescopes. Carleton College undergraduate students will be integrally involved in all aspects of data acquisition and analysis, including participation in two month-long trips to the Australia Telescope National Facility.

在这里，Weisberg博士将进行一项放射媒介研究计划，其中包括三个主要主题。前两个使用脉冲星作为研究其他物理现象的工具 - 即星际培养基和相对论重力。第三个重点是研究脉冲星本身的排放和演变。乳房具有几种独特的特性，使它们成为星际培养基的理想探针。具体而言，它们的排放是脉冲，两极化的和尖的。它们的脉冲允许测量分散延迟，从而导致星际电子密度确定。它们的高极化允许对法拉第旋转的测量，从而产生沿视线的银河磁场测量。它们是尖端的，可确保信号沿视线探测一根细圆柱。在该项目的这一部分中，将进行五项主要光谱和偏振学研究，以利用这三个特性来促进对星际介质中各种现象的理解，包括中性原子，分子和电离区域的特征，尤其是在最小的尺度上，是对第一个binary persister of Persister for Psr b1913+16，是对最小的尺度的研究。引力。尽管现在探测重力波发射的准确性受到系统效应的限制，但仍有新的有趣的相对主义现象在这里进行研究。预计在未来十年内，“ shapiro”重力传播延迟将成为可衡量的，这将导致另外两项相对论测试，这可能会限制其他可行的重力理论。 “大地”旋转轴进动使视线慢慢漂移到脉冲星上，从而使发射光束罕见地沿正交的方向与其通常的表示。此处支持的其他观察结果将有助于进一步限制梁的形状，这是一种对发射机制研究有用的基本数量。 在发现这些物体后的40年中，脉冲星排放机制和脉冲星内部性质的细节仍然不清楚。 Weisberg博士和学生将着眼于建立光束几何形状，研究和创建经验发射模型，进行一系列测量其两极分化排放的实验。这些观察结果将与Arecibo，Green Bank和Parkes望远镜一起进行。卡尔顿学院的本科生将积极参与数据获取和分析的各个方面，包括参加为期两个月的澳大利亚望远镜国家设施的旅行。