【作者】 蔡新贵；

【导师】 张妙静；

【作者基本信息】 广西师范大学 ， 理论物理， 2009， 硕士

【摘要】 本工作探讨物态方程中κ0对II型超新星瞬时爆发的影响,并且对超新星爆发能量的四种定义进行了研究。综述了II型超新星的相关理论。包括大质量恒星的演化、超新星的分类、超新星的爆发机制、引起恒星不稳定坍缩的物理因素等;同时论述了Ⅱ型超新星爆发所应用的数值模拟相关物理因素和数值处理方法,包括电子俘获的一般分析方法、“四粒子”模型的物态方程、广义相对论流体动力学方法和数值模拟差分方法。本文通过使用2002年Woosley提供的新前身星模型数据,计算前身星为11Μ、13Μ、15Μ、20Μ、25Μ、30Μ、35Μ、40Μ的超新星,重新探讨了物态方程中κ0对超新星铁核坍缩、激波传播时间、爆发能量、整个铁核的温度( t 4时刻)的影响及详细讨论超新星爆发能量的四种定义。研究结果表明:1.在星核坍缩阶段,κ0越大,τc(1o)llap时间越短,但对τc(o2l)lap的影响不大。发现爆发能量越大,τt 4 ? t11越短;2.κ0越大,ρmcax值越小, cYL、Ye c、Yνc的值随κ0的增大而增大,但中心的熵却减小(变化都不大);3. t 4时刻,调节κ0的值,发现κ0越大,在内核,则温度越低,在外核,温度几乎不变;4.考察κ0的变化对不同太阳质量模型的爆发能量影响时,我们发现对于不同太阳质量模型时,最佳的对称物质的压缩模量κ0的取值不一样,通过对8个模型的对比,发现:κ0=210MeV较为合适;5.在探讨爆发能量的四种定义时,通过对八个不同太阳质量模型的考察, E x(p2)是较为合适的选择。这些结论说明κ0对超新星铁核坍缩、激波传播时间、爆发能量、整个铁核的温度( t 4时刻)等有重要的影响。这对于超新星爆发的研究有着重要的意义。更多还原

【Abstract】 In this paper,κ0 in the equation of state effects on the prompt explosin of type II supernova and the four definitions of explosion energy are investigated.The theory related toⅡsupernova is summarized. Including the evolution of massive stars,the reason of causing collapsing instability in stars.Explosion mechanism of type II supernova,the classify characters of SN are introduced,the physical factors relevant to SNII explosion numerrical simulation and numerical simulation methods are introduced,which include electron capture(EC),four model state equation ,general relativity hydrodynamic method,numerical simulation me- thods.In this paper, we study the effects ofκ0in the equation of state on the core collapse ,shock propagation ,explosion energy and temperature of iron core at t 4, using the data of presupernova given by Woosley in 2002.The presupernova models which we are studied are11Μ,13Μ,15Μ,20Μ,25Μ,30Μ,35Μand40Μ, and also make a discussion in detail about the four definitions of explosion energy. The results of this paper are these:First,at the stage of the core collapse,the augmenttation ofκ0 shorten the collapse time(τc(1o)llap),but there is a little influence on collapse time(τc(o2l)lap),in the same time,the augmentation of explosion energy lowers the time ofτt 4 ? t11.Second,when we augment the value ofκ0,the inner density (ρmcax) and entropy are reduced,lepton abundance( YL c),electron abundance( Ye c) and neutrion abundance( Yνc ) of the inner core are augmentted.Third,at t 4,regulating the value ofκ0,we find that the augmentation ofκ0 lowers the internal core tempera- ture,but there is a little effect on the exterior core temperature.Fourth,we abserve that the change ofκ0 influences the explosion energy,found that the most suitableκ0 is different for 8 models,from the comparison of the eight models,foud that the suitable value is 210 MeV .Fifth,when we use 8 models to discuss the definition of explosion energy,found that the definition of E x(p2) is more suitable than others.The above conclusions show thatκ0 has a great effect on the core collapse ,shock propagation,explosion energy and core temerature(at t 4),and it is significance for the research of supernova.更多还原