【作者】 吕静；

【导师】 汪定雄； 邹远川；

【作者基本信息】 华中科技大学 ， 理论物理， 2013， 博士

【摘要】 伽玛射线暴(简称伽玛暴),一种宇宙空间中的伽玛射线在短期产生的强烈的脉冲现象。在上世纪60年代后期被Vela卫星意外的发现,这引起了天文学家和天体物理学家的广泛关注。在过去的二十年中,一些空间项目如康普顿伽玛射线天文台(CGRO)、BeppoSAX、HETE II,与地面上的光学、红外、射电观测站一起改变着我们对伽玛暴的理解,让我们知道了伽玛暴是伴有长时间余辉的一类宇宙学事件。而2004年专门用于伽玛暴研究的Swift卫星和2008年可以对伽玛暴更宽能段研究的Fermi卫星的发射成功,带我们进入了伽玛暴研究的新时代。本论文研究的主要方向是,统计分析伽玛暴洛伦兹因子与各向同性光度的相关性,并利用伽玛中心引擎的中微子主导吸积流(NDAF)模型解释这种相关性。这一研究涉及伽玛暴的中心引擎模型理论以及伽玛暴观测中各物理量的数据处理和分析。论文的内容结构如下：第一章是对伽玛暴的综述,主要包括伽玛暴瞬时辐射阶段、余辉阶段的相关观测以及辐射模型、伽玛暴中心引擎理论和重要经验关系,重点介绍了伽玛暴观测上的各物理量和中心引擎理论。第二章是对伽玛暴初始洛伦兹因子与各向同性光度或各向同性能量的统计拟合,以及用NDAF模型解释这一相关关系。伽玛暴的初始洛伦兹因子是理解伽玛暴物理的一个重要参量,尤其对理解伽玛暴瞬时辐射的物理起源非常关键。其中介绍了几种求解洛伦兹因子的常用方法,详细的NDAF模型理论,并给出了已知红移的51个伽玛暴的洛伦兹因子的统计。第三章是关于伽玛暴的射电光度与X射线光度的相关性研究,以及这一关系是否可以与太阳、冷星、活动星系核等统一的问题。第四章是对伽玛暴领域中已解决问题和期望未来解决问题的总结和展望。本论文提供了关于伽玛暴初始洛伦兹因子的详细计算方法,以及初始洛伦兹因子与各向同性光度或各向同性能量的相关关系,并用伽玛暴中心引擎的黑洞加NDAF盘模型很好的解释了这一相关关系。更多还原

【Abstract】 Gamma-Ray Burst (GRB) is a phenomenon of short and intense pulses of gamma rays occurred in space. GRBs were unexpected discovery in the late1960s by the Vela satellite, which caused widespread concern of astronomers and astrophysicists. In the last two decades, some space missions---CGRO/BATSE, BeppoSAX, HETE II (High-Energy Transient Explorer), together with the ground-based optical, infrared, and radio observatories are changing our understanding of GRBs. GRBs are cosmological events and accompanied with long-lasting afterglows. The Swift satellite dedicated to study the GRBs and the Fermi satellite covering large energy range, successfully launched in2004and2008respectively, have taken us into a new era of GRB research.The main direction of this thesis is the correlation between Lorentz factor and mean isotropic luminosity/energy of GRBs, and interpretation with neutrino dominated accretion flow (NDAF) model of central engine of GRBs. This work involves the central engine of GRB and data statistical analysis of observed quantities of GRBs. The thesis is structured as follows:Chapter I is the review of GRBs, including the observations of prompt radiation and afterglow of GRBs, radiation mechanisms, central engine of GRBs and some important relations of GRBs. In Chapter II, we give the statistical fitting and theoretical analysis with NDAF model between initial Lorentz factor and the isotropic equivalent luminosity or isotropic equivalent energy of GRBs. The initial Lorentz factor is a very important parameter to understand the physics of GRBs, especially for understanding the physical origin of the prompt GRB emission phase. We apply several commonly used methods to constrain the initial Lorentz factor of GRBs in Chapter II, and give the details of NDAF model and the Lorentz factor statistics of51GRBs with known redshifts. Chapter III is about the correlation studies between radio luminosity and X-ray luminosity of GRBs, and whether the relationship can be extended to the sun, cool stars and active galactic nuclei. Finally, we summarize the important findings of GRBs in the past several years and the problems we hope to solve in future.This thesis provides detailed calculations of the initial Lorentz factor of gamma-ray burst, and gives the relationship between initial Lorentz factor and isotropic equivalent luminosity of GRBs, meanwhile it proposes an interpretation to the statistical correlation within the framework of a blackhole-NDAF disk GRB central engine model.更多还原