本文關(guān)鍵詞： 超新星 豐度梯度 壓強梯度 爆發(fā)能量　出處：《廣西師范大學》2010年碩士論文　論文類型：學位論文

【摘要】： 在核心坍縮型超新星爆發(fā)機制的數(shù)值模擬中,能量問題一直是導致超新星爆發(fā)不能成功的主要原因,但是超新星爆發(fā)的巨大能量是得到了大量觀測和實驗支持的。如果考慮它的引力勢能作為爆發(fā)的主要能量,在原有的計算方法下會發(fā)現(xiàn)釋放的總的引力勢能很有限,而中微子泄漏以及鐵星核光裂解消耗大量的能量都是必須的。為了解決這個困難,Baron和Coopemtein提出了調(diào)節(jié)引力常數(shù)的方法,王貽仁等提出了“等效厚度”的假設。而本文則根據(jù)羅志全等人提出的有關(guān)壓強梯度影響Ⅱ型超新星爆發(fā)的相關(guān)理論,在有限的引力能釋放的情況下,通過豐度梯度和壓強梯度的修改來提高激波能量,使得瞬時強爆炸能夠成功。豐度梯度和壓強梯度過去一直沒有引起人們的足夠重視,但是本文發(fā)現(xiàn)它與超新星瞬時爆發(fā)能量有著十分密切的關(guān)系。利用Woosley等人得出的前身星模型數(shù)據(jù)和王貽仁小組開發(fā)的Ⅱ型超新星爆發(fā)模擬程序“SNⅡ-WLYW89”,模擬了質(zhì)量為11M⊙、12M⊙、13M⊙、14M⊙、15M⊙的五個超新星爆發(fā)過程。 數(shù)值結(jié)果表明,在坍縮階段,適當修改元素豐度梯度和壓強梯度,激波能量能夠傳到鐵核邊緣。當重核豐度梯度,中子豐度梯度,質(zhì)子豐度梯度,α粒子豐度梯度的改變量β都取1.03時,除模型S11、S15的爆發(fā)能稍有降低外,其它三個模型的爆發(fā)能都增大了;當總的元素豐度梯度的改變量β取0.90,α,n和p混合壓強梯度,輻射壓強梯度,中微子壓強梯度的改變量β都取1.02時,五個模型的爆發(fā)能都有不同程度的提高;當總的壓強梯度的改變量β取1.05時,除S15的激波能量不能轉(zhuǎn)到鐵星核邊緣,其它四個模型的爆發(fā)能都提高了;當重核豐度梯度,中子豐度梯度,質(zhì)子豐度梯度,α粒子豐度梯度的改變量β都取1.03 ,總的元素豐度梯度的改變量β都取1.03,重核物質(zhì)壓強梯度,α,n和p混合壓強梯度,輻射壓強梯度,中微子壓強梯度的改變量β都取1.02,總的壓強梯度的改變量β取1.05時,元素豐度梯度的改變并沒有改變爆發(fā)時間,而壓強梯度的改變使得爆發(fā)時間延長了。修改總的元素豐度梯度后,熵增大了,而物質(zhì)溫度在t3 , t 4時刻有所降低,在其它時刻變化不明顯。通過數(shù)值模擬可見,在有限的引力能量釋放的情況下,豐度梯度和壓強梯度的調(diào)整增強了對流傳能機制,提高了爆發(fā)能量,使得瞬時強爆炸能夠成功。
[Abstract]:In the numerical simulation of the mechanism of the core collapse supernova explosion, the energy problem has been the main reason for the failure of the supernova explosion. But the great energy of the supernova burst is supported by a lot of observations and experiments. If the gravitational potential energy is considered as the main energy of the explosion, the total gravitational potential energy released under the original calculation method will be very limited. However, neutrino leakage and photocracking of iron star nuclei are necessary. In order to solve this problem, Baron and Coopemtein proposed a method to adjust the gravitational constant. Wang Yi-ren and others put forward the hypothesis of "equivalent thickness". In this paper, according to the theory of pressure gradient affecting the explosion of type II supernova proposed by Luo Zhiquan and others, under the condition of limited gravitational energy release, By modifying the abundance gradient and the pressure gradient to increase the shock energy and make the instantaneous strong explosion succeed, the abundance gradient and the pressure gradient have not been paid enough attention to in the past. However, it is found that it is closely related to the instantaneous burst energy of supernova. Using the former star model data obtained by Woosley et al and the simulation program "SN 鈪，

本文編號：1529377