RUI: Relativistic Compton Scattering in Neutron Star Magenetospheres

RUI：中子星磁层中的相对论康普顿散射

• 批准号: 9876670
• 负责人: Peter Gonthier
• 金额: $ 7.92万
• 依托单位: Hope College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9876670&HistoricalAwards=false
• 关键词: RUI; Relativistic; Compton; Scattering; Neutron

Abstract - Gonthier AST 9876670The recent observations of soft gamma-ray repeaters and anomalous X-ray pulsars furnish data for greater evidence of the existence of a class of neutron stars with surface magnetic fields exceeding the critical field of 4.4 ten thousand billion Gauss. This research effort seeks to understand the role of strong-field, quantum electrodynamic (QED) processes such as Compton scattering, pair production, photon splitting, and cyclotron and synchrotron radiation in the magnetospheres of neutron stars. In this study, an acceleration model of electrons and positrons will be developed to provide a self-consistent description of the input parameters to a Monte Carlo cascade model that simulates the emission of X-rays and gamma rays from the magnetosphere. The main effort will be to study the role of relativistic Compton scattering as it operates with other QED processes, to develop approximate expressions of the exact QED scattering cross section and incorporate them in a full acceleration-cascade model. Previous studies have assumed that Compton scattering can be adequately described by the non-relativistic Compton scattering cross section (Thomson limit) below resonance and at the resonance, or the Klein-Nishina cross section for scattering above the resonance. Consequently, these studies have not included the effects of the strong magnetic fields. Since these processes are highly dependent upon the polarization of the interacting photons, polarized differential rates for each QED process will be investigated. Pulse profiles as well as phase dependent spectra of the soft gamma-ray repeaters, anomalous X-ray pulsars, the high field gamma-ray pulsars, PSR 1509-58 and PSR 0656+14, along with the Crab, Vela and Geminga pulsars will be simulated and compared with those observed by the Compton Gamma-Ray Observatory (CGRO), the Rossi X-ray Timing Explorer (RXTE) and the Advanced Satellite for Cosmology and Astrophysics (ASCA). The calculated thermal X-ray emission from polar cap heating by pair-created positrons returning to the surface will be compared with the observations of Roentgen Satellite (ROSAT) and upcoming measurements from the Chandra X-ray Observatory that is scheduled to be launched in 1999. The study of the strong field effects on the inverse Compton scattering process will provide insight into the particle-photon interactions associated with a variety of pulsar phenomena, including burst spectra of soft gamma-ray repeaters and the transport of thermal radiation through neutron star atmospheres.

摘要- Gonthier AST 9876670最近对软伽马射线中继器和异常X射线源的观测提供了更多的证据，证明存在一类表面磁场超过4.4万亿高斯临界场的中子星。 这项研究旨在了解强场，量子电动力学（QED）过程，如康普顿散射，对生产，光子分裂，回旋加速器和同步辐射在中子星的磁层中的作用。 在这项研究中，将开发电子和正电子的加速模型，为模拟磁层X射线和伽马射线发射的蒙特卡罗级联模型提供输入参数的自洽描述。 主要的努力将是研究相对论康普顿散射的作用，因为它与其他QED过程，开发精确的QED散射截面的近似表达式，并将它们纳入一个完整的加速级联模型。 以前的研究认为，康普顿散射可以充分描述的非相对论康普顿散射截面（汤姆逊极限）低于共振和共振，或克莱因-西科散射截面以上的共振。 因此，这些研究没有包括强磁场的影响。 由于这些过程是高度依赖于相互作用的光子的偏振，每个QED过程的偏振微分率将被调查。 模拟了软γ射线中继星、异常X射线源星、高场γ射线源星PSR 1509-58和PSR 0656+14以及沿着的Crab、Vela和Geminga源星的脉冲轮廓和相位谱，并与康普顿γ射线天文台（CGRO）的观测结果进行了比较。Rossi X射线定时探测器（RXTE）和宇宙学和天体物理学高级卫星（ASCA）。 计算出的返回到表面的成对产生的正电子加热极冠产生的热X射线发射将与伦琴卫星的观测结果和计划于1999年发射的钱德拉X射线观测站即将进行的测量结果进行比较。 研究强场对逆康普顿散射过程的影响将有助于深入了解与各种脉冲星现象有关的粒子-光子相互作用，包括软伽马射线中继器的爆发光谱和热辐射通过中子星星大气的传输。