發(fā)布時(shí)間：2018-06-11 16:47

  本文選題：天體物理學(xué) + 高能中微子　； 參考：《南京大學(xué)》2015年博士論文

【摘要】：極高能宇宙線是來自地外的能量高于1018電子伏特(eV)的高能粒子,關(guān)于其起源的研究一直以來是高能天體物理領(lǐng)域和粒子天體物理領(lǐng)域的熱點(diǎn)問題。近些年由于大型探測器(如Pierre Auger)的觀測,極高能宇宙線的研究取得很大進(jìn)展。然而由于極高能宇宙線事件數(shù)仍相對較少,以及其在從源到地球傳播過程中的復(fù)雜性,人們也常常借助于觀測宇宙線伴隨產(chǎn)生的次級粒子(如中微子)來獲得其起源的額外信息。最近,位于南極的IceCube中微子天文臺探測到了54個(gè)能量分布在60TeV-3PeV內(nèi)的中微子,開啟了高能中微子天文的新時(shí)代。我們在這篇論文里,研究了這些高能中微子的天體物理起源以及它們和極高能宇宙線之間的可能聯(lián)系。在論文的第一章里,我們簡單介紹了相關(guān)的背景知識,包括IceCube高能中微子的觀測、極高能宇宙線的觀測以及它們的候選天體。在第二章里,我們討論了這些中微子起源于極高能宇宙線源的一般性條件。根據(jù)該條件我們可以初步排除一些模型,然后我們提出恒星形成星系中的中等相對論性巨超新星遺跡作為IceCube高能中微子的源。在第三章里,我們深入討論了伽瑪射線暴是否可以作為觀測到的中微子的源。我們首先修正了IceCube團(tuán)隊(duì)在他們早期文章中對于伽瑪射線暴中微子流量的過高估算。然后我們討論了一些未觸發(fā)探測器的“暗暴“能否解釋IceCube高能中微子。在第四章里,我們計(jì)算了極高能宇宙線在星系際空間傳播效應(yīng),發(fā)現(xiàn)從巨超新星遺跡產(chǎn)生的極高能宇宙線經(jīng)傳播后的能譜及化學(xué)組成可以與觀測符合。在第五章,我們主要研究了極高能宇宙線在磁場中的傳播,并根據(jù)Pierre Auger天文臺對于極高能宇宙線化學(xué)成份與到達(dá)方向分布的觀測得到了對源的距離以及金屬豐度的限制。第六章介紹我們對伽瑪暴高能光子起源的研究。我們通過對伽瑪暴多波段余輝輻射進(jìn)行擬合,研究了瞬時(shí)和晚期高能光子的起源。在最后一章,我們討論和總結(jié)了這篇論文中的工作,并指出一些可行的后續(xù)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.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：P172.4;P141.8
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本文編號：2005982