本文選題：鈉雙線　切入點(diǎn)：Ia型超新星　出處：《清華大學(xué)》2013年碩士論文

【摘要】：由于Ia超新星具有光亮度且相對(duì)均勻，它們被長(zhǎng)期用作研究宇宙的“標(biāo)準(zhǔn)燭光”測(cè)量河外距離，，并在揭示宇宙加速膨脹這一重大發(fā)現(xiàn)上起了至關(guān)重要的作用。然而其爆發(fā)前身星性質(zhì)的不確定性卻不利于使用Ia超新星進(jìn)行更加精確的宇宙學(xué)研究。 現(xiàn)在人們普遍相信Ia超新星起源于碳氧白矮星的熱核爆炸。然而，對(duì)于具體是兩個(gè)C+O白矮星的并合引發(fā)的爆炸（所謂的“雙簡(jiǎn)并”圖景），還是雙星系統(tǒng)中中心白矮星對(duì)其富H/He的伴星物質(zhì)的持續(xù)吸積引發(fā)的（“單簡(jiǎn)并”模型），卻無(wú)定論。在單簡(jiǎn)并模型中，從星體被吹出的物質(zhì)會(huì)聚集形成可探測(cè)的星周物質(zhì)；而在雙簡(jiǎn)并模型中此種現(xiàn)象則不明顯。因此探測(cè)星周物質(zhì)/塵埃是區(qū)分兩類模型的關(guān)鍵。 靜止波長(zhǎng)在5890和5896的鈉雙線（Na I D）是很好的塵埃氣體指示器。在這篇文章中，我們測(cè)量了來(lái)自哈佛大學(xué)天體物理中心的2603條Ia超新星光譜中Na I D線吸收強(qiáng)度及其隨時(shí)間的演化。發(fā)現(xiàn)了如下三個(gè)事實(shí)：1）部分超新星主星系鈉強(qiáng)度呈現(xiàn)形狀類似“根號(hào)”的演化規(guī)律，這與我們建立的星周物質(zhì)被超新星輻射電離的模型非常吻合；2）這些具有變化鈉特征的超新星傾向于具有很高的拋射物速度（“高速”超新星）；3）高速超新星比正常拋射物速度的超新星（“正常速度”超新星）系統(tǒng)性地顏色偏紅且Na吸收更強(qiáng)。 以上事實(shí)證明了部分Ia超新星周圍致密星周塵埃的存在，且對(duì)“高速”（HV）和“正常速度”（NV）超新星可能具有的兩種不同前身星演化模型給予極強(qiáng)的暗示。大量星周塵埃更容易聚集在“高速”超新星周圍使我們相信，這類Ia超新星傾向于起源于“單簡(jiǎn)并”系統(tǒng)的爆炸。而其比“正常速度”超新星系統(tǒng)偏紅也與除星際塵埃影響外，“高速”超新星還遭遇額外的星周塵埃消光這一事實(shí)不謀而合。
[Abstract]:Because Ia supernovae are luminous and relatively uniform, they have long been used for "standard candlelight" measurements of extragalactic distances in the study of the universe. It plays an important role in revealing the great discovery of the accelerating expansion of the universe. However, the uncertainty of the character of its predecessor star is not conducive to a more accurate cosmological study using Ia supernova. It is now widely believed that the Ia supernova originated from a thermonuclear explosion of carbon dioxide white dwarfs. For the explosion caused by the combination of the two C-O white dwarfs (the so-called "double degenerate" picture, or the continuous accretion of the central white dwarf to its H/He rich companion star material in the binary system, the "single degenerate" model, however, Indeterminate. In a single degenerate model, The matter blown out from the stars gathers to form detectable circumstellar matter, but this phenomenon is not obvious in the double degenerate model. Therefore, detecting the circumstellar matter / dust is the key to distinguish the two models. Sodium I D at rest wavelengths of 5890 and 5896 is a good indicator of dust and gas. In this article, We have measured the absorption intensity of Na D lines and their evolution over time in 2603 Ia supernova spectra from the Harvard Astrophysical Center. The law of evolution like "root sign", This is very consistent with our model of supernova radiation ionization of perisatellite matter. (2) these supernovae with varying sodium characteristics tend to have very high projectile velocity ("high speed" supernova) supernova than normal supernova. Projective velocity supernovae ("normal velocity" supernovae) are systematically reddish and Na absorbers are stronger. The above facts prove the existence of the dense circumstellar dust around some Ia supernovae. And gives a very strong indication of two different models of evolution of precursors that supernova "high speed" (HVV) and "normal speed" (NVN) may have. Large amounts of circumstellar dust tend to gather around "high speed" supernovae to convince us. This type of Ia supernova tends to originate from an explosion in a "single degenerate" system, and its redder than "normal velocity" supernova system coincides with the fact that, in addition to interstellar dust, the "high-speed" supernova suffers from additional circumstellar dust extinction.
【學(xué)位授予單位】：清華大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：P145.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳佳;王曉鋒;;宇宙的燈塔:Ⅰa型超新星——漫談2011年諾貝爾物理學(xué)獎(jiǎng)[J];現(xiàn)代物理知識(shí);2011年06期

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