本文選題：超新星遺跡 + 分子云��； 參考：《南京大學》2014年博士論文

【摘要】：大質量恒星形成于分子云中致密云核的坍縮,而其演化最后終結于核坍縮超新星爆發(fā)。在這些恒星短暫的一生中,它們強烈的星風和電離輻射能清空出一個腔體。若其存在環(huán)境分子云,我們就可能觀測到超新星遺跡撞擊腔壁分子氣體。超新星遺跡與分子云的相互作用對于研究稠密氣體的物理和化學過程,追溯前身星演化,探索宇宙線強子作用都具有重要意義。 我的博士論文針對分子云環(huán)境中的超新星遺跡Kes78.Kes79和W28進行了多波段的觀測研究,并理論上探討了分子云內空腔與前身星質量的關系。 以超新星遺跡Kes78為起點,我們研究了該遺跡的分子云環(huán)境并開展了對其東北殼層的XMM-Newton X射線光譜分析。通過CO三個躍遷的觀測,我們建立了遺跡與～81km s-1的分子云腔體相互作用的證據(jù),包括展寬的12CO譜線和相對增強的12CO J=2-1/J=1-0比例。我們還探明了其環(huán)境分子云分布,并為探究其強子伽瑪射線輻射提供指引。Kes78東北殼層上的X射線來自亞電離的熱(～1.5keV)氣體,其密度為-0.1cm-3,可能是團際介質。遺跡的年齡約為6kyr。根據(jù)分子云腔體的大小,我們估算出其前身星的初始質量約為21M(?)。 在一些超新星遺跡周圍出現(xiàn)的腔狀和弧狀分子云使我們意識到,前身星星風對分子云的塑造也許能有助于研究其前身星質量。我們發(fā)現(xiàn)分子云環(huán)境中的大質量恒星的主序星風泡大小與恒星質量存在一個接近線性的關系Rb≈1.22M/M⊙-9.16pc。由于8到25-30M(?)的恒星的演化會進入紅超巨星階段而不產(chǎn)生Wolf-Rayet星風,主序階段的星風泡就決定了分子云腔體的尺度。而相比起來,光致電離的影響卻很小。該關系為分子云腔體中的超新星遺跡提供了一種難得的診斷前身星質量的新工具。利用這個關系,我們估算了8個超新星遺跡的前身星質量：Kes69,Kes75,Kes78,3C396,3C397,HC40,Vela和RXJ1713-3946。 熱混合型超新星遺跡往往與分子云相互作用,由于這類遺跡具有諸多有趣卻未得到解釋的觀測特征,是近年觀測和研究的熱點。W28作為熱混合型超新星遺跡的原型,其熱混合型形態(tài)起源還不清楚。我們開展了對W28的XMM-Newton成圖和光譜研究。遺跡內部的X射線輻射是非均勻的,一個冷的非電離平衡等離子體和一個達到碰撞電離平衡的熱氣體的組合能最好地解釋觀測到的X射線。這個雙溫模型下,冷的亞電離的成分來自蒸發(fā)的團塊氣體。多個觀測證據(jù)支持W28內部存在小云團的蒸發(fā)過程,而這個過程或許可以解釋遺跡的熱混合型形態(tài)。我們將這個雙溫模型應用到不同的小區(qū)域中,發(fā)現(xiàn)吸收、溫度和密度在遺跡內的分布是隨空間變化的,說明遺跡在一個不均勻的環(huán)境中演化,而更密的介質在遺跡的東部和北部。除了雙溫模型,遺跡內部的X射線還可能用電子溫度為0.6keV的過電離氣體模型來描述。過電離氣體的復合時標約為2.9×104yr,接近遺跡的動力學年齡。W28東北殼層上的X射線存在一個0.3keV的低溫成分,而硬X射線可能是熱起源(溫度～0.61keV)也可能是非熱起源(光子譜指數(shù)～2)。若為非熱起源,非熱電子經(jīng)受庫倫損失的韌致輻射是最可能的解釋。 通過開展CO觀測,我們給出了熱混合型超新星遺跡Kes79與～105kms-1分子云作用的運動學證據(jù)。Kes79在X射線波段存在豐富的明亮絲狀結構以及一個彌散的暗暈。遺跡整體的X射線輻射需要用雙溫(0.23+1.05keV)的模型來描述,其高溫成分存在S和Ar的超豐,說明了拋射物的存在。在西北射電內殼層外,我們發(fā)現(xiàn)一個X射線團塊具有不尋常的高溫(2.0-0.4+0.5keV)和增豐的Mg, Si, S和Ar。暗暈的氣體與明亮絲狀結構不同,金屬豐度趨于甚至低于太陽豐度。在邊緣區(qū)域,暗暈的X射線輻射用一個高溫成分(0.9-1.4keV)就可以解釋。我們研究了遺跡的整體演化性質,得到遺跡的激波速度為833-12+3km s-1,年齡為～5.8kyr。對比多波段分析結果,我們認為遺跡的雙殼層結構和熱混合型形態(tài)都是投影效應。根據(jù)遺跡分子云腔的大小和拋射物中金屬元素的豐度,我們估算出其前身星是質量為～12Me的B1型星。 在研究Kes79的過程中,我們幸運地在其南部發(fā)現(xiàn)了一顆11.56s的X射線脈沖星3XMM J185246.6+003317。根據(jù)其自轉減慢速率1.1×10-13s s-1和周期11.5587126(4)s可以得到脈沖星的表面偶極磁場3.6×1013G,特征年齡1.7Myr,自轉能損2.8×1030erg s--1。通過對它的X射線光譜分析,我們發(fā)現(xiàn)共振回旋散射模型能給出最佳擬合,同時,黑體輻射也可以描述X射線光譜。從2008年到2009年總共7個月的觀測中,該脈沖星的的光譜性質發(fā)生了劇烈的變化：其光度由2.7×1034erg s-1降至4.6×1033erg s-1,而黑體輻射溫度由約0.8keV降至月0.6keV。3XMM J185246.6+003317的X射線光度遠遠高于其自轉能損,排除了由自轉供能的可能。它在光學和紅外波沒有探測到對應天體,而且2008年之前的多次X射線觀測中它都沒有出現(xiàn),再結合時序和光譜分析,我們認為3XMM J185246.6+003317是一顆新發(fā)現(xiàn)的暫現(xiàn)低磁磁星,而它在2008年的一次爆發(fā)正好被XMM-Newton觀測到。2001年Chandra對它的觀測將它的寧靜光度上限限制到4×1032erg s--1。由于該磁星與Kes79的吸收柱密度類似,可以認為它們處于相似的距離～7.1kpc上。它是目前自轉最慢的暫現(xiàn)強磁星,也是第三顆已知低磁強磁星。3XMM J185246.6+003317與其北部的超新星遺跡Kes79和遺跡內部反磁星是否存在可能的物理聯(lián)系則需要未來的觀測給出確定性的答案。
[Abstract]:Large mass stars form in the collapse of dense cloud nuclei in molecular clouds, and their evolution ends in the end of nuclear collapse supernova. In the short lifetime of these stars, their strong stellar winds and ionizing radiation can empty out a cavity. If there is an environmental molecular cloud, we may observe the molecular gas of the supernova remnant impacting the wall of the cavity. The interaction between supernova and molecular clouds is of great significance in studying the physical and chemical processes of dense gas, tracing the evolution of the precursors and exploring the role of the cosmic ray hadron.
My doctoral thesis has conducted a multi band observation study of supernova remnants Kes78.Kes79 and W28 in the molecular cloud environment, and theoretically discussed the relationship between the cavity of the molecular cloud and the mass of the precursor.
Taking the supernova remnant Kes78 as the starting point, we studied the molecular cloud environment of the remains and analyzed the XMM-Newton X ray spectra of its northeastern shell. By observing the three transitions of CO, we established the evidence for the interaction between the remains and the molecular cloud cavity of 81km s-1, including the broadened 12CO spectrum and the relatively enhanced 12CO J=2-1/J. =1-0 ratio. We also explore the distribution of its environmental molecular cloud and provide guidance to explore its hadronic gamma ray radiation to guide the X rays from the.Kes78 shell of the northeastern shell from subionized heat (to 1.5keV). The density is -0.1cm-3 and may be an intergroup medium. The age of the remnant is about 6kyr. based on the size of the molecular cloud cavity, and we estimate its predecessor The initial mass of a star is about 21M (?).
The cavity and arc molecular clouds appearing around some supernova remnants make us aware that the molding of the precursor to the molecular clouds may help to study the mass of the precursors. We found that the size of the main stars in the mass stars in the molecular cloud environment is in a close linear relationship with the mass of the stars, Rb 1.22M/M -9. 16pc. because the evolution of 8 to 25-30M (?) stars will enter the red supergiant stage and does not produce the Wolf-Rayet star wind, the main sequence stage star bubble determines the scale of the molecular cloud cavity. Compared with the photoionization, the effect of the photoionization is very small. This relationship provides a rare diagnostic precursor star quality in the supernova remnant of the molecular cloud cavity. Using this relationship, we estimate the precursor mass of 8 supernova remnants: Kes69, Kes75, Kes78,3C396,3C397, HC40, Vela and RXJ1713-3946..
Hot mixed supernova remains often interact with molecular clouds. Because these sites have many interesting but unexplained observational features, it is a hot spot of.W28 as a prototype of hot mixed supernova remnants in recent years. The origin of the thermal hybrid form is not clear. We have carried out the XMM-Newton mapping and spectrum of W28. Research. The X ray radiation inside the site is heterogeneous, and a cold non ionized equilibrium plasma and a combination of thermal gases that reach the collision ionization equilibrium can best explain the observed X rays. Under this double temperature model, the cold subionization component comes from the evaporated mass of gas. Several observations support the existence of small internal presence in W28. The process of vaporization of clouds may explain the thermal mixed form of the remains. We apply this double temperature model to different cell domains and find that the distribution of absorption, temperature and density varies with space in the remains, indicating the evolution of the remains in an uneven environment, and the denser medium in the east of the remains. In addition to the north, in addition to the double temperature model, the X ray inside the remains may also be described with an over ionized gas model of the electron temperature of 0.6keV. The composite time of the over ionized gas is about 2.9 x 104yr, close to the kinetic age of the remnant.W28, and the X ray on the northeastern shell has a 0.3keV low temperature component, while the hard X ray may be the thermal origin (temperature ~ (temperature). 0.61keV) may also be non thermal origin (photon spectral index 2). If it is non thermal origin, the most probable explanation for the loss of bremsstrahlung in the non thermal electrons is Kulun.
Through the CO observation, we give the kinematic evidence for the action of the thermal mixed supernova remnant Kes79 and the 105kms-1 molecular cloud..Kes79 is rich in the bright filamentous structure and a diffuse dark halo in the X ray band. The X ray radiation of the whole remains is described by the model of the double temperature (0.23+ 1.05keV), and its high temperature composition exists in S and in the presence of S. Ar's super abundance shows the existence of a projectile. Outside the inner shell of the northwest radio, we found that a X ray mass with unusual high temperature (2.0-0.4+0.5keV) and added Mg, Si, S and Ar. is different from the bright filamentous structure, and the metal abundance tends to be even lower than the solar abundance. In the marginal region, the X ray radiation of the faint halo is used in one The high temperature component (0.9-1.4keV) can be explained. We have studied the whole evolution properties of the remains. The shock wave velocity of the remains is 833-12+3km s-1, and the age of ~ 5.8kyr. contrast multi band analysis results. We think that the double shell structure and the thermal mixed form of the remains are all projection effects. We estimate that the precursor of the metal element is B1 star with mass of 12Me.
In the study of Kes79, we luckily found a 11.56s X ray pulsar 3XMM J185246.6+003317. in its southern part, which can get the surface dipole magnetic field of the pulsar by its rotation and slow rate of 1.1 x 10-13s S-1 and the period 11.5587126 (4) s. The characteristic age 1.7Myr, the rotation energy loss of 2.8 * 1030erg s--1. through it We found that the resonance cyclotron scattering model can give the best fitting, and the blackbody radiation can also describe the X ray spectrum. From 2008 to 2009, the spectral properties of the pulsar changed dramatically: the luminosity from 2.7 x S-1 to 4.6 x 1033erg s-1, and the black body radiation temperature. The X ray luminosity from about 0.8keV to 0.6keV.3XMM J185246.6+003317 is far higher than its rotation energy loss, excluding the possibility of rotation energy supply. It has not detected the corresponding celestial bodies in the optical and infrared waves, and it did not appear in the multiple X ray observations before 2008, and then combined with time series and spectral analysis, we think 3XMM J18524 6.6+003317 is a newly discovered temporary low magnetic magnetic star, and its outbreak in 2008 was just observed by XMM-Newton to.2001 Chandra for its observation to limit its tranquil photometric upper limit to 4 x 1032erg s--1. because the magnetic star is similar to the density of the absorption column of Kes79, and it is considered to be at a similar distance to 7.1kpc. At present, the slowest rotation of the magnetic star, and the possible physical link between the third known low magnetic strong magnetic stars.3XMM J185246.6+003317 and the supernova remnant Kes79 in the north and the internal antimagnetic stars in the remains, will require definite answers to future observations.
【學位授予單位】：南京大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：P145.3

【參考文獻】

相關期刊論文 前1條

1 ;Spatial distribution of metal emissions in supernova remnant 3C 397 viewed with Chandra and XMM[J];Science China(Physics,Mechanics & Astronomy);2010年S1期

，

本文編號：2028929