RUI: Radio Studies of the Interstellar Medium and Pulsars

RUI：星际介质和脉冲星的射电研究

• 批准号: 9530710
• 负责人: Joel Weisberg
• 金额: $ 14.37万
• 依托单位: Carleton College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9530710&HistoricalAwards=false
• 关键词: RUI; Radio; Studies; Interstellar; Medium

Weisberg AST-9530710 Radioastronomical studies of the interstellar medium and pulsars will be carried out. Observations will be conducted at the Arecibo Observatory in Puerto Rico, the Parkes radio telescope in Australia, the Green Bank Telescope in West Virginia, and the Very Large Array in New Mexico. In particular, the upgraded Arecibo Observatory telescope and the Green Bank Telescope will be highly sensitive instruments that will enable one to make much more sensitive observations than previously possible. The interstellar medium studies are divided into three main categories: In the first, neutral hydrogen line absorption spectra of distant pulsars will be obtained and measured and kinematic distances will be determined from these spectra. The electron densities along the pulsar-Earth lines of sight will then be derived from distances and dispersion measures, and models of the Galactic distribution of electrons will be compared with these results. In the second category, the spatial structure and physical properties of interstellar hydrogen will be studied with neutral hydrogen line absorption measurements of high- latitude and nearby pulsars and recombination line observations in the directions of pulsars. The third category consists of studies of the Galactic magnetic field through Faraday rotation measurements of polarized pulsar signals. Temporal and small- scale spatial variations will be studied in one experiment, while the broad structure of the magnetic field will be investigated in another. There are also three main categories of intrinsic pulsar investigations: First, full Stokes parameter pulsar polarization profiles will be measured and calibrated, and morphological classifications will be assigned on the basis of these and all other published observations. Second, polarized profiles will be examined for temporal variations that could indicate free precession or intrinsic beam changes as well as the Galactic magnetic field variations di scussed above. Third, the emission beam geometry will be studied via empirical/geometrical analyses and fits of the rotating vector model to measured position angles. Undergraduate students at Carleton College will be involved in the research program.

Weisberg AST-9530710 将对星际介质和星际星体进行射电天文学研究。观测将在波多黎各的阿雷西博天文台、澳大利亚的帕克斯射电望远镜、西弗吉尼亚的绿色班克望远镜和新墨西哥州的甚大阵列进行。特别是，升级后的阿雷西博天文台望远镜和绿色班克望远镜将是高度灵敏的仪器，使人们能够进行比以前更灵敏的观测。 星际介质的研究主要分为三大类：第一类，将获得和测量遥远恒星的中性氢线吸收光谱，并根据这些光谱确定运动学距离。电子密度沿着脉冲星-地球视线，然后将来自距离和分散措施，和银河系的电子分布模型将与这些结果进行比较。在第二类中，将通过高纬和邻近恒星的中性氢线吸收测量以及恒星方向上的复合线观测来研究星际氢的空间结构和物理性质。第三类包括通过极化脉冲星信号的法拉第旋转测量研究银河磁场。时间和小尺度空间变化将在一个实验中研究，而磁场的广泛结构将在另一个实验中研究。 也有三个主要类别的内在脉冲星的调查：第一，完整的斯托克斯参数脉冲星偏振剖面将被测量和校准，形态分类将分配的基础上，这些和所有其他已发表的意见。第二，将检查偏振剖面的时间变化，这可能表明自由岁差或固有的光束变化以及上面讨论的银河磁场变化。第三，发射光束几何形状将通过经验/几何分析和旋转矢量模型与测量位置角的拟合来研究。 卡尔顿学院的本科生将参与这项研究计划。