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博士（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）伽马射线观测站最近发现的一批新的未确认的扩展TeV（太电子伏）源的多波长特性进行系统分析。TeV辐射是在超新星遗迹、高质量双星和年轻的磁化中子星等天体中宇宙射线加速点的示踪物。因此，对TeV源的研究不仅可以让我们了解这些物体，还可以了解我们银河系中最具活力的过程。在该项目的框架内，将收集和减少X射线、红外线、光学和无线电数据，并分析35-40 TeV扩展源的多波长特性。将特别注意这些TeV源的环境，因为密集的云或局部增强的红外辐射背景的存在下，可以密切联系到TeV的属性，并可以提供一个关键的理解TeV源的性质。多波长数据一旦汇集成一个方便的公共在线数据库，将有助于对排放模型进行有意义的测试。特别是，对于在年轻的高能恒星附近发现的大量未识别的TeV源，将通过将其多波长特性拟合到作为该项目一部分开发的脉冲星风模型来测试两者之间的联系。多区模型将追踪脉冲星风特性的演变，直到距离脉冲星很远，同时考虑到辐射和膨胀损失，并考虑到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）的空间分辨和综合多波长光谱，并将其与收集到的数据进行比较。通过将模型与数据拟合，将有可能推断出残留脉冲星风的性质（例如，能量学、粒子密度、磁化），并检查相邻的恒星是否能产生这样的风。这种联系意味着：（1）大多数扩展星系TeV源确实是遗迹PWNe，尽管在许多情况下还没有发现脉冲星，（2）遗迹PWNe在伽马射线中最突出，并且可以具有比以前基于低频观测所认为的更大的空间范围，（3）类星体和PWNe是影响银河系及其组成部分结构和演化的有效宇宙线工厂。该项目将自然地整合基础研究和教育，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。它还将作为佛罗里达大学天文系高能天体物理学小组的启动项目。该项目将提供一个新发现的TeV源的多波长特性的独特在线数据库，这将对广泛的天体物理界有用。该项目的成果将通过在两所大学举行的外联活动中举办的受欢迎的讲座和图像展览向公众介绍（例如，宾州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）。

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).