Collaborative Research: Unidentified Galactic TeV Sources: Neutron Star Connection

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。Kargaltsev(佛罗里达大学)和Pavlov博士(宾夕法尼亚州立大学)将对Hess(高能立体系统)伽马射线天文台最近发现的一组新的不明扩展TeV(太电子伏)源的多波长特性进行系统分析。TeV辐射是对超新星遗迹、大质量双星和年轻的磁化中子星等物体中宇宙线加速位置的示踪。因此，对TeV源的研究使人们不仅可以了解这些天体，还可以了解我们银河系中最高能量的过程。在该项目的框架内，将收集和整理X射线、红外、光学和无线电数据，并分析35-40个扩展TeV源的每个源的多波长特性。将特别注意这些TeV源的环境，因为致密云或局部增强的红外辐射背景的存在可能与TeV的性质密切相关，并可为了解TeV源的性质提供关键。一旦作为一个方便的公共在线数据库放在一起，多波长数据将有助于对排放模型进行有意义的测试。特别是，对于在年轻的高能脉冲星附近发现的一大批不明TeV源，将通过将它们的多波长特性与作为该项目一部分开发的脉冲星风模型相匹配来测试两者之间的联系。多区域模型将跟踪脉冲星风特性的演变到距离脉冲星很远的地方，考虑到辐射和膨胀损失，并考虑轻子风和强子风分量。模型输出将包括不同年龄和能量的脉冲星风星云(PWNe)的空间分辨和积分的多波长光谱，并与收集的数据进行比较。通过将模型与数据进行匹配，将有可能推断残存脉冲星风的特性(例如，能量、粒子密度、磁化强度)，并检查这种风是否可以由邻近的脉冲星产生。这种联系将意味着：(1)尽管在许多情况下还没有发现脉冲星，但大多数扩展的银河系TeV源确实是遗迹PWNe，(2)遗迹PWNe在伽马射线中最为突出，其空间范围可能比之前基于较低频率的观测所认为的要大得多，(3)脉冲星和PWNe是宇宙射线的有效工厂，影响我们银河系及其组成部分的结构和演化。该项目将通过让两所大学的研究生和本科生参与高能天体物理学的尖端多波长研究，自然地将基础研究和教育结合起来。它还将作为佛罗里达大学天文学系一个高能天体物理学小组的初创公司。该项目将提供一个关于新发现的TeV源的多波长特性的独特的在线数据库，这将对广大天体物理界有用。该项目的成果将通过在两所大学举办的外联活动(例如，宾夕法尼亚州立大学为初中和高中科学教师举办的天文学在职讲习班)上的受欢迎的讲座和图像展览向公众展示。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Dr. Kargaltsev (University of Florida) and Dr. Pavlov (Pennsylvania State University) will undertake a systematic analysis of the multiwavelength properties of a new population of unidentified extended TeV (teraelectron volt) sources recently discovered by the HESS (High Energy Stereoscopic System) gamma-ray observatory. TeV emission is a tracer of the cosmic ray acceleration sites in objects such as supernova remnants, high-mass binaries, and young, magnetized neutron stars. Therefore, the study of TeV sources allows one to learn not only about these objects but also about the most energetic processes in our Galaxy. In the framework of this project archival X-ray, infrared, optical and radio data will be collected and reduced, and the multiwavelength properties of each of the 35-40 extended TeV sources will be analyzed. Particular attention will be paid to the environments of these TeV sources because the presence of dense clouds or locally enhanced infrared radiation background can be intimately linked to the TeV properties and can provide a key to understanding the nature of the TeV source. Once put together as a convenient public on-line database, the multiwavelength data will facilitate meaningful tests of the emission models. In particular, for a large subset of unidentified TeV sources that are found near young energetic pulsars, the connection between the two will be tested by fitting their multiwavelength properties to the pulsar wind models developed as part of the project. The multi-zone models will trace the evolution of the pulsar wind properties out to large distances from the pulsar, taking into account the radiative and expansion losses and allowing for both leptonic and hadronic wind components. The model output will include the spatially-resolved and integrated multiwavelength spectra for pulsar wind nebulae (PWNe) of various ages and energetics, which will be compared with the data collected. By fitting the models to the data, it will be possible to infer the properties of the relic pulsar winds (e.g., energetics, particle density, magnetization) and check whether or not such winds can be produced by neighboring pulsars. The connection would imply that (1) most of the extended galactic TeV sources are indeed relic PWNe even though in many cases no pulsar has been identified yet, (2) relic PWNe are most prominent in gamma-rays and can have a much larger spatial extent than previously thought based on observations at lower frequencies, and (3) pulsars and PWNe are efficient factories of cosmic rays that influence the structure and evolution of our Galaxy and its constituents. The project will naturally integrate the fundamental research and education by involving graduate and undergraduate students at two universities in the cutting-edge, multiwavelength research in high-energy astrophysics. It will also serve as a start-up for a High Energy Astrophysics group at the Department of Astronomy in the University of Florida. The project will provide a unique on-line database of multi-wavelength properties of newly discovered TeV sources, which will be useful for the broad astrophysical community. The results of the project will be presented to the general public through popular lectures and image exhibitions at the outreach events held at both universities (e.g., the Penn State In-Service Workshops in Astronomy for middle- and high-school science teachers).