高能中微子与极高能宇宙线起源天体的理论研究

发布时间：2018-06-11 16:47

  本文选题：天体物理学 + 高能中微子　； 参考：《南京大学》2015年博士论文

【摘要】：极高能宇宙线是来自地外的能量高于1018电子伏特(eV)的高能粒子,关于其起源的研究一直以来是高能天体物理领域和粒子天体物理领域的热点问题。近些年由于大型探测器(如Pierre Auger)的观测,极高能宇宙线的研究取得很大进展。然而由于极高能宇宙线事件数仍相对较少,以及其在从源到地球传播过程中的复杂性,人们也常常借助于观测宇宙线伴随产生的次级粒子(如中微子)来获得其起源的额外信息。最近,位于南极的IceCube中微子天文台探测到了54个能量分布在60TeV-3PeV内的中微子,开启了高能中微子天文的新时代。我们在这篇论文里,研究了这些高能中微子的天体物理起源以及它们和极高能宇宙线之间的可能联系。在论文的第一章里,我们简单介绍了相关的背景知识,包括IceCube高能中微子的观测、极高能宇宙线的观测以及它们的候选天体。在第二章里,我们讨论了这些中微子起源于极高能宇宙线源的一般性条件。根据该条件我们可以初步排除一些模型,然后我们提出恒星形成星系中的中等相对论性巨超新星遗迹作为IceCube高能中微子的源。在第三章里,我们深入讨论了伽玛射线暴是否可以作为观测到的中微子的源。我们首先修正了IceCube团队在他们早期文章中对于伽玛射线暴中微子流量的过高估算。然后我们讨论了一些未触发探测器的“暗暴“能否解释IceCube高能中微子。在第四章里,我们计算了极高能宇宙线在星系际空间传播效应,发现从巨超新星遗迹产生的极高能宇宙线经传播后的能谱及化学组成可以与观测符合。在第五章,我们主要研究了极高能宇宙线在磁场中的传播,并根据Pierre Auger天文台对于极高能宇宙线化学成份与到达方向分布的观测得到了对源的距离以及金属丰度的限制。第六章介绍我们对伽玛暴高能光子起源的研究。我们通过对伽玛暴多波段余辉辐射进行拟合,研究了瞬时和晚期高能光子的起源。在最后一章,我们讨论和总结了这篇论文中的工作,并指出一些可行的后续工作。
[Abstract]:Very high energy cosmic rays are high energy particles with energy higher than 1018 electron volts from the earth. The origin of these particles has always been a hot topic in the field of high energy astrophysics and particle astrophysics. In recent years, great progress has been made in the study of very high energy cosmic rays due to the observation of large detectors such as Pierre Auger. However, because the number of extremely high energy cosmic ray events is still relatively small and its complexity in the process of propagating from source to earth, Additional information about the origin of cosmic rays is often obtained by observing secondary particles (such as neutrinos) associated with cosmic rays. Recently, the IceCube Neutrino Observatory in Antarctica detected 54 neutrinos distributed in 60TeV-3 PeV, opening a new era of high-energy neutrino astronomy. In this paper we study the astrophysical origin of these high-energy neutrinos and their possible association with extremely high energy cosmic rays. In the first chapter, we briefly introduce the relevant background knowledge, including the observation of IceCube high energy neutrino, the observation of extremely high energy cosmic rays and their candidate objects. In Chapter 2, we discuss the general conditions under which these neutrinos originate from extremely high energy cosmic ray sources. According to this condition, we can preliminarily exclude some models, and then we propose that the intermediate relativistic supernova relic in star forming galaxies can be used as the source of IceCube high energy neutrino. In chapter 3, we discuss in depth whether gamma-ray bursts can be used as sources of observed neutrinos. We first corrected the overestimation of neutrino flux by the IceCube team in their earlier article. Then we discuss whether some untriggered "dark storms" can explain the IceCube high energy neutrino. In chapter 4, we calculate the propagating effect of very high energy cosmic rays in intergalactic space. We find that the energy spectrum and chemical composition of the extremely high energy cosmic rays produced from giant supernova traces after propagation are in agreement with observations. In chapter 5, we mainly study the propagation of very high energy cosmic rays in magnetic field, and according to the observation of the distribution of chemical composition and direction of arrival of extremely high energy cosmic rays at the Pierre Auger Observatory, we obtain the limits of the distance of the source and the abundance of metals in the light of the observation of the distribution of the chemical composition and the direction of arrival of the extremely high energy cosmic rays. Chapter 6 introduces our research on the origin of high energy photons of gamma storms. The origin of instantaneous and late high energy photons is studied by fitting the multiband afterglow radiation of gamma storms. In the last chapter, we discuss and summarize the work in this paper, and point out some feasible follow-up work.
【学位授予单位】：南京大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：P172.4;P141.8
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本文编号：2005982