Type Ia Supernovae in semi-detached binary systems

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Ia超新星的几个问题

Ia超新星的几个问题
李宗伟;裴寿镛
【期刊名称】《紫金山天文台台刊》
【年(卷),期】1999(018)003
【摘要】首先利用Ａｓｉａｇｏ超新星星表对Ｉａ超新星作了统计分析。

其次用具有精确测光的Ｉａ超新星对其均匀性及多样性进行了研究。

旋涡星系中Ｉａ超新星的产生率比椭圆星系的要高。

最高的Ｉａ超新星只出现于晚型旋涡星系中；而旋涡星系及早型的椭圆星系都是暗Ｉａ超新星的寄主星系。

离星系中心越近Ｉａ超新星的光度弥散有增加的趋势，但这一趋势对蓝Ｉａ超新星不明显。

利用色指数可将Ｉａ超新星划分为蓝超新星及红超新星。

蓝Ｉａ超新星构成了相对均匀的Ｉａ超新星样本，是较好的距离指示器；而红Ｉａ超新星的存在则表明了Ｉａ超新星整体多样性的特点。

最后，我们还探讨了Ｉａ超新星中碳点火的非线性问题。

【总页数】8页(P303-310)
【作者】李宗伟;裴寿镛
【作者单位】北京师范大学天文学系,北京;北京师范大学物理学系,北京
【正文语种】中文
【中图分类】P145.3
【相关文献】
1.Ia型超新星的消光改正 [J], 李军;姜碧沩
2.Ia型超新星的诞生率以及光度与寄主星系的统计关系 [J], 梁文科;王建成
3.IA型超新星r——宇宙的标准烛光 [J], 北辰
4.信息论背景下Ia型超新星宇宙学的贝叶斯统计分析和距离对偶关系检验 [J], 马骢
5.宇宙新近诞生SN2014J的Ia类超新星照亮M82星系 [J],
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宇宙邻居;谁是我们最近的天体邻居(宇宙邻居;谁是我们最近的天体邻居英语)

宇宙邻居;谁是我们最近的天体邻居宇宙中有无数星球和天体，但我们最近的天体邻居是谁呢？这个问题一直困扰着人类，因为了解我们的宇宙邻居不仅可以帮助我们更好地理解宇宙，还可以为未来的太空探索提供重要的参考。

在探讨“宇宙邻居”这个话题之前，让我们先来了解一下太阳系中的一些重要天体。

太阳系中有八大行星，其中最靠近太阳的是水星，然后依次往外依次是金星、地球、火星、木星、土星、天王星和海王星。

除了这些行星，太阳系中还有一颗矮行星——冥王星，以及一颗叫作塞德娜的天体。

然而，距离我们最近的天体邻居并不在太阳系内。

我们最近的天体邻居是半人马座阿尔法星，也被称为半人马座Centauri A、半人马座离子A或半人马座α星。

这颗恒星是离我们太阳系最近的一颗恒星，距离地球约4.24光年。

半人马座阿尔法星实际上是一个三合星系统，包括半人马座A、半人马座B和半人马座C。

半人马座A和半人马座B是一对双星，而半人马座C则是一颗红矮星，离半人马座AB较远。

虽然半人马座离子A距离我们很近，但要想到达那里仍然需要数千年的时间，这对于目前的人类太空技术来说仍然是一个遥远的距离。

然而，人类对于这颗恒星的研究却从未停止过，科学家们通过各种手段积极探索着半人马座离子A，希望能够了解更多关于这颗恒星和其周围可能存在的行星的信息。

了解我们最近的天体邻居不仅可以帮助我们更好地了解宇宙的构成和演化，还可以为人类未来的太空探索开辟新的可能性。

或许有一天，人类可以利用先进的太空技术实现对半人马座离子A的探索，甚至建立基地在那里。

这将是人类探索宇宙的又一个伟大壮举，也将为人类文明的发展带来新的契机。

无论我们的宇宙邻居是谁，对于人类来说，探索宇宙、了解宇宙、甚至在宇宙中建立自己的存在，都是人类永恒的梦想和追求。

随着科技的不断进步和人类对宇宙的认知不断深入，相信我们对宇宙邻居的了解也将越来越深入，人类的太空探索也会迈向更加辉煌的未来。

实用英语：天文学名词词汇（四）

Eagle nebula ( M 16 ) 鹰状星云earty cluster 早型星系团early earth 早期地球early planet 早期⾏星early-stage star 演化早期星early stellar evolution 恒星早期演化early sun 早期太阳earth-approaching asteroid 近地⼩⾏星earth-approaching comet 近地彗星earth-approaching object 近地天体earth-crossing asteroid 越地⼩⾏星earth-crossing comet 越地彗星earth-crossing object 越地天体earth orientation parameter 地球定向参数earth rotation parameter 地球⾃转参数eccentric-disk model 偏⼼盘模型effect of relaxation 弛豫效应Egg nebula ( AFGL 2688 ) 蛋状星云electronographic photometry 电⼦照相测光elemental abundance 元素丰度elliptical 椭圆星系elliptical dwarf 椭圆矮星系emulated data 仿真数据emulation 仿真encounter-type orbit 交会型轨道enhanced network 增强络equatorial rotational velocity ⾚道⾃转速度equatorium ⾏星定位仪equipartition of kinetic energy 动能均分eruptive period 爆发周期Eskimo nebula ( NGC 2392 ) 爱斯基摩星云estimated accuracy 估计精度estimation theory 估计理论EUVE, Extreme Ultraviolet Explorer 〈EUVE〉极紫外探测器Exclamation Mark galaxy 惊叹号星系Exosat 〈Exosat〉欧洲 X 射线天⽂卫星extended Kalman filter 扩充卡尔曼滤波器extragalactic jet 河外喷流extragalactic radio astronomy 河外射电天⽂extrasolar planet 太阳系外⾏星extrasolar planetary system 太阳系外⾏星系extraterrestrial intelligence 地外智慧⽣物extreme helium star 极端氦星。

罕见的双星系统文献英语翻译

罕见"闪光灯"恒星实际可能是双星系统This Hubble image shows a a mysteriousprotostar, LRLL 54361, that behaves like a flashing light. The image wasreleased Feb. 7, 2013.CREDIT: NASA, ESA, J. Muzerolle (STScI)这幅哈勃望远镜图像显示了一个神秘原恒星LRLL 54361,其行为像一个闪光灯。

该图像发布于2013年2月7日。

来源:美国宇航局、欧空局、J·沐泽洛尔(太空望远镜科学研究所)An odd flashing star may actually be a pairof cosmic twins: two newly formed ba by stars that circle each other closely andflash like a strobe light, scientist s say.一颗古怪闪烁恒星实际上可能是一对宇宙双胞胎:两颗新形成幼年恒星彼此紧密环绕并且像一个闪光灯一样闪烁,科学家说。

Astronomers discovered the nascent starsystem, called LRLL 54361, with the infr ared Spitzer observatory and the HubbleSpace Telescope, and say the rare cosmic find could offer a chance to studystar formation and early evolution. It is on ly the third such "strobelight" object ever seen, researchers said.天文学家通过斯皮策红外观测站和哈勃太空望远镜发现了这个新生称为LRLL 54361恒星系统,并且表示这个罕见宇宙发现可能提供一种研究恒星形成和早期演化机会。

天文学专用词汇

Galactic aggregate 银河星集Galactic astronomy 银河系天文Galactic bar 银河系棒galactic bar 星系棒galactic cannibalism 星系吞食galactic content 星系成分galactic merge 星系并合galactic pericentre 近银心点Galactocentric distance 银心距galaxy cluster 星系团Galle ring 伽勒环Galilean transformation 伽利略变换Galileo 〈伽利略〉木星探测器gas-dust complex 气尘复合体Genesis rock 创世岩Gemini Telescope 大型双子望远镜Geoalert, Geophysical Alert Broadcast 地球物理警报广播giant granulation 巨米粒组织giant granule 巨米粒giant radio pulse 巨射电脉冲Ginga 〈星系〉X 射线天文卫星Giotto 〈乔托〉空间探测器glassceramic 微晶玻璃glitch activity 自转突变活动global change 全球变化global sensitivity 全局灵敏度GMC, giant molecular cloud 巨分子云g-mode g 模、重力模gold spot 金斑病GONG, Global Oscillation Network 太阳全球振荡监测网GroupGPS, global positioning system 全球定位系统Granat 〈石榴〉号天文卫星grand design spiral 宏象旋涡星系gravitational astronomy 引力天文gravitational lensing 引力透镜效应gravitational micro-lensing 微引力透镜效应great attractor 巨引源Great Dark Spot 大暗斑Great White Spot 大白斑grism 棱栅GRO, Gamma-Ray Observatory γ射线天文台guidscope 导星镜GW Virginis star 室女GW 型星habitable planet 可居住行星Hakucho 〈天鹅〉X 射线天文卫星Hale Telescope 海尔望远镜halo dwarf 晕族矮星halo globular cluster 晕族球状星团Hanle effect 汉勒效应hard X-ray source 硬X 射线源Hay spot 哈伊斑HEAO, High-Energy Astronomical 〈HEAO〉高能天文台Observatoryheavy-element star 重元素星heiligenschein 灵光Helene 土卫十二helicity 螺度heliocentric radial velocity 日心视向速度heliomagnetosphere 日球磁层helioseismology 日震学helium abundance 氦丰度helium main-sequence 氦主序helium-strong star 强氦线星helium white dwarf 氦白矮星Helix galaxy （NGC 2685 ）螺旋星系Herbig Ae star 赫比格Ae 型星Herbig Be star 赫比格Be 型星Herbig-Haro flow 赫比格-阿罗流Herbig-Haro shock wave 赫比格-阿罗激波hidden magnetic flux 隐磁流high-field pulsar 强磁场脉冲星highly polarized quasar （HPQ ）高偏振类星体high-mass X-ray binary 大质量X 射线双星high-metallicity cluster 高金属度星团;高金属度星系团high-resolution spectrograph 高分辨摄谱仪high-resolution spectroscopy 高分辨分光high - z 大红移Hinotori 〈火鸟〉太阳探测器Hipparcos, High Precision Parallax 〈依巴谷〉卫星Collecting SatelliteHipparcos and Tycho Catalogues 〈依巴谷〉和〈第谷〉星表holographic grating 全息光栅Hooker Telescope 胡克望远镜host galaxy 寄主星系hot R Coronae Borealis star 高温北冕R 型星HST, Hubble Space Telescope 哈勃空间望远镜Hubble age 哈勃年龄Hubble distance 哈勃距离Hubble parameter 哈勃参数Hubble velocity 哈勃速度hump cepheid 驼峰造父变星Hyad 毕团星hybrid-chromosphere star 混合色球星hybrid star 混合大气星hydrogen-deficient star 缺氢星hydrogenous atmosphere 氢型大气hypergiant 特超巨星Ida 艾达（小行星243号）IEH, International Extreme Ultraviolet 〈IEH〉国际极紫外飞行器HitchhikerIERS, International Earth Rotation 国际地球自转服务Serviceimage deconvolution 图象消旋image degradation 星象劣化image dissector 析象管image distoration 星象复原image photon counting system 成象光子计数系统image sharpening 星象增锐image spread 星象扩散度imaging polarimetry 成象偏振测量imaging spectrophotometry 成象分光光度测量immersed echelle 浸渍阶梯光栅impulsive solar flare 脉冲太阳耀斑infralateral arc 外侧晕弧infrared CCD 红外CCDinfrared corona 红外冕infrared helioseismology 红外日震学infrared index 红外infrared observatory 红外天文台infrared spectroscopy 红外分光initial earth 初始地球initial mass distribution 初始质量分布initial planet 初始行星initial star 初始恒星initial sun 初始太阳inner coma 内彗发inner halo cluster 内晕族星团integrability 可积性Integral Sign galaxy （UGC 3697 ）积分号星系integrated diode array （IDA ）集成二极管阵intensified CCD 增强CCDIntercosmos 〈国际宇宙〉天文卫星interline transfer 行间转移intermediate parent body 中间母体intermediate polar 中介偏振星international atomic time 国际原子时International Celestial Reference 国际天球参考系Frame （ICRF ）intraday variation 快速变化intranetwork element 网内元intrinsic dispersion 内廪弥散度ion spot 离子斑IPCS, Image Photon Counting System 图象光子计数器IRIS, Infrared Imager / Spectrograph 红外成象器/摄谱仪IRPS, Infrared Photometer / Spectro- 红外光度计/分光计meterirregular cluster 不规则星团; 不规则星系团IRTF, NASA Infrared Telescope 〈IRTF〉美国宇航局红外Facility 望远镜IRTS, Infrared Telescope in Space 〈IRTS〉空间红外望远镜ISO, Infrared Space Observatory 〈ISO〉红外空间天文台isochrone method 等龄线法IUE, International Ultraviolet 〈IUE〉国际紫外探测器ExplorerJewel Box （NGC 4755 ）宝盒星团Jovian magnetosphere 木星磁层Jovian ring 木星环Jovian ringlet 木星细环Jovian seismology 木震学jovicentric orbit 木心轨道J-type star J 型星Juliet 天卫十一Jupiter-crossing asteroid 越木小行星Kalman filter 卡尔曼滤波器KAO, Kuiper Air-borne Observatory 〈柯伊伯〉机载望远镜Keck ⅠTelescope 凯克Ⅰ望远镜Keck ⅡTelescope 凯克Ⅱ望远镜Kuiper belt 柯伊伯带Kuiper-belt object 柯伊伯带天体Kuiper disk 柯伊伯盘LAMOST, Large Multi-Object Fibre 大型多天体分光望远镜Spectroscopic TelescopeLaplacian plane 拉普拉斯平面late cluster 晚型星系团LBT, Large Binocular Telescope 〈LBT〉大型双筒望远镜lead oxide vidicon 氧化铅光导摄象管Leo Triplet 狮子三重星系LEST, Large Earth-based Solar 〈LEST〉大型地基太阳望远镜Telescopelevel-Ⅰcivilization Ⅰ级文明level-Ⅱcivilization Ⅱ级文明level-Ⅲcivilization Ⅲ级文明Leverrier ring 勒威耶环Liapunov characteristic number 李雅普诺夫特征数（LCN ）light crown 轻冕玻璃light echo 回光light-gathering aperture 聚光孔径light pollution 光污染light sensation 光感line image sensor 线成象敏感器line locking 线锁line-ratio method 谱线比法Liner, low ionization nuclear 低电离核区emission-line regionline spread function 线扩散函数LMT, Large Millimeter Telescope 〈LMT〉大型毫米波望远镜local galaxy 局域星系local inertial frame 局域惯性架local inertial system 局域惯性系local object 局域天体local star 局域恒星look-up table （LUT ）对照表low-mass X-ray binary 小质量X 射线双星low-metallicity cluster 低金属度星团;低金属度星系团low-resolution spectrograph 低分辨摄谱仪low-resolution spectroscopy 低分辨分光low - z 小红移luminosity mass 光度质量luminosity segregation 光度层化luminous blue variable 高光度蓝变星lunar atmosphere 月球大气lunar chiaroscuro 月相图Lunar Prospector 〈月球勘探者〉Ly-α forest 莱曼-α 森林MACHO （massive compact halo 晕族大质量致密天体object ）Magellan 〈麦哲伦〉金星探测器Magellan Telescope 〈麦哲伦〉望远镜magnetic canopy 磁蓬magnetic cataclysmic variable 磁激变变星magnetic curve 磁变曲线magnetic obliquity 磁夹角magnetic period 磁变周期magnetic phase 磁变相位magnitude range 星等范围main asteroid belt 主小行星带main-belt asteroid 主带小行星main resonance 主共振main-sequence band 主序带Mars-crossing asteroid 越火小行星Mars Pathfinder 火星探路者mass loss rate 质量损失率mass segregation 质量层化Mayall Telescope 梅奥尔望远镜Mclntosh classification 麦金托什分类McMullan camera 麦克马伦电子照相机mean motion resonance 平均运动共振membership of cluster of galaxies 星系团成员membership of star cluster 星团成员merge 并合merger 并合星系; 并合恒星merging galaxy 并合星系merging star 并合恒星mesogranulation 中米粒组织mesogranule 中米粒metallicity 金属度metallicity gradient 金属度梯度metal-poor cluster 贫金属星团metal-rich cluster 富金属星团MGS, Mars Global Surveyor 火星环球勘测者micro-arcsec astrometry 微角秒天体测量microchannel electron multiplier 微通道电子倍增管microflare 微耀斑microgravitational lens 微引力透镜microgravitational lensing 微引力透镜效应microturbulent velocity 微湍速度millimeter-wave astronomy 毫米波天文millisecond pulsar 毫秒脉冲星minimum mass 质量下限minimum variance 最小方差mixed-polarity magnetic field 极性混合磁场MMT, Multiple-Mirror Telescope 多镜面望远镜moderate-resolution spectrograph 中分辨摄谱仪moderate-resolution spectroscopy 中分辨分光modified isochrone method 改进等龄线法molecular outflow 外向分子流molecular shock 分子激波monolithic-mirror telescope 单镜面望远镜moom 行星环卫星moon-crossing asteroid 越月小行星morphological astronomy 形态天文morphology segregation 形态层化MSSSO, Mount Stromlo and Siding 斯特朗洛山和赛丁泉天文台Spring Observatorymultichannel astrometric photometer 多通道天测光度计（MAP ）multi-object spectroscopy 多天体分光multiple-arc method 复弧法multiple redshift 多重红移multiple system 多重星系multi-wavelength astronomy 多波段天文multi-wavelength astrophysics 多波段天体物。

黑洞的准正模式(quasinormal modes)

Quasi-Normal Modes of Stars and Black HolesKostas D.KokkotasDepartment of Physics,Aristotle University of Thessaloniki,Thessaloniki54006,Greece.kokkotas@astro.auth.grhttp://www.astro.auth.gr/˜kokkotasandBernd G.SchmidtMax Planck Institute for Gravitational Physics,Albert Einstein Institute,D-14476Golm,Germany.bernd@aei-potsdam.mpg.dePublished16September1999/Articles/Volume2/1999-2kokkotasLiving Reviews in RelativityPublished by the Max Planck Institute for Gravitational PhysicsAlbert Einstein Institute,GermanyAbstractPerturbations of stars and black holes have been one of the main topics of relativistic astrophysics for the last few decades.They are of partic-ular importance today,because of their relevance to gravitational waveastronomy.In this review we present the theory of quasi-normal modes ofcompact objects from both the mathematical and astrophysical points ofview.The discussion includes perturbations of black holes(Schwarzschild,Reissner-Nordstr¨o m,Kerr and Kerr-Newman)and relativistic stars(non-rotating and slowly-rotating).The properties of the various families ofquasi-normal modes are described,and numerical techniques for calculat-ing quasi-normal modes reviewed.The successes,as well as the limits,of perturbation theory are presented,and its role in the emerging era ofnumerical relativity and supercomputers is discussed.c 1999Max-Planck-Gesellschaft and the authors.Further information on copyright is given at /Info/Copyright/.For permission to reproduce the article please contact livrev@aei-potsdam.mpg.de.Article AmendmentsOn author request a Living Reviews article can be amended to include errata and small additions to ensure that the most accurate and up-to-date infor-mation possible is provided.For detailed documentation of amendments, please go to the article’s online version at/Articles/Volume2/1999-2kokkotas/. Owing to the fact that a Living Reviews article can evolve over time,we recommend to cite the article as follows:Kokkotas,K.D.,and Schmidt,B.G.,“Quasi-Normal Modes of Stars and Black Holes”,Living Rev.Relativity,2,(1999),2.[Online Article]:cited on<date>, /Articles/Volume2/1999-2kokkotas/. The date in’cited on<date>’then uniquely identiﬁes the version of the article you are referring to.3Quasi-Normal Modes of Stars and Black HolesContents1Introduction4 2Normal Modes–Quasi-Normal Modes–Resonances7 3Quasi-Normal Modes of Black Holes123.1Schwarzschild Black Holes (12)3.2Kerr Black Holes (17)3.3Stability and Completeness of Quasi-Normal Modes (20)4Quasi-Normal Modes of Relativistic Stars234.1Stellar Pulsations:The Theoretical Minimum (23)4.2Mode Analysis (26)4.2.1Families of Fluid Modes (26)4.2.2Families of Spacetime or w-Modes (30)4.3Stability (31)5Excitation and Detection of QNMs325.1Studies of Black Hole QNM Excitation (33)5.2Studies of Stellar QNM Excitation (34)5.3Detection of the QNM Ringing (37)5.4Parameter Estimation (39)6Numerical Techniques426.1Black Holes (42)6.1.1Evolving the Time Dependent Wave Equation (42)6.1.2Integration of the Time Independent Wave Equation (43)6.1.3WKB Methods (44)6.1.4The Method of Continued Fractions (44)6.2Relativistic Stars (45)7Where Are We Going?487.1Synergism Between Perturbation Theory and Numerical Relativity487.2Second Order Perturbations (48)7.3Mode Calculations (49)7.4The Detectors (49)8Acknowledgments50 9Appendix:Schr¨o dinger Equation Versus Wave Equation51Living Reviews in Relativity(1999-2)K.D.Kokkotas and B.G.Schmidt41IntroductionHelioseismology and asteroseismology are well known terms in classical astro-physics.From the beginning of the century the variability of Cepheids has been used for the accurate measurement of cosmic distances,while the variability of a number of stellar objects(RR Lyrae,Mira)has been associated with stel-lar oscillations.Observations of solar oscillations(with thousands of nonradial modes)have also revealed a wealth of information about the internal structure of the Sun[204].Practically every stellar object oscillates radially or nonradi-ally,and although there is great diﬃculty in observing such oscillations there are already results for various types of stars(O,B,...).All these types of pulsations of normal main sequence stars can be studied via Newtonian theory and they are of no importance for the forthcoming era of gravitational wave astronomy.The gravitational waves emitted by these stars are extremely weak and have very low frequencies(cf.for a discussion of the sun[70],and an im-portant new measurement of the sun’s quadrupole moment and its application in the measurement of the anomalous precession of Mercury’s perihelion[163]). This is not the case when we consider very compact stellar objects i.e.neutron stars and black holes.Their oscillations,produced mainly during the formation phase,can be strong enough to be detected by the gravitational wave detectors (LIGO,VIRGO,GEO600,SPHERE)which are under construction.In the framework of general relativity(GR)quasi-normal modes(QNM) arise,as perturbations(electromagnetic or gravitational)of stellar or black hole spacetimes.Due to the emission of gravitational waves there are no normal mode oscillations but instead the frequencies become“quasi-normal”(complex), with the real part representing the actual frequency of the oscillation and the imaginary part representing the damping.In this review we shall discuss the oscillations of neutron stars and black holes.The natural way to study these oscillations is by considering the linearized Einstein equations.Nevertheless,there has been recent work on nonlinear black hole perturbations[101,102,103,104,100]while,as yet nothing is known for nonlinear stellar oscillations in general relativity.The study of black hole perturbations was initiated by the pioneering work of Regge and Wheeler[173]in the late50s and was continued by Zerilli[212]. The perturbations of relativistic stars in GR wereﬁrst studied in the late60s by Kip Thorne and his collaborators[202,198,199,200].The initial aim of Regge and Wheeler was to study the stability of a black hole to small perturbations and they did not try to connect these perturbations to astrophysics.In con-trast,for the case of relativistic stars,Thorne’s aim was to extend the known properties of Newtonian oscillation theory to general relativity,and to estimate the frequencies and the energy radiated as gravitational waves.QNMs wereﬁrst pointed out by Vishveshwara[207]in calculations of the scattering of gravitational waves by a Schwarzschild black hole,while Press[164] coined the term quasi-normal frequencies.QNM oscillations have been found in perturbation calculations of particles falling into Schwarzschild[73]and Kerr black holes[76,80]and in the collapse of a star to form a black hole[66,67,68]. Living Reviews in Relativity(1999-2)5Quasi-Normal Modes of Stars and Black Holes Numerical investigations of the fully nonlinear equations of general relativity have provided results which agree with the results of perturbation calculations;in particular numerical studies of the head-on collision of two black holes [30,29](cf.Figure 1)and gravitational collapse to a Kerr hole [191].Recently,Price,Pullin and collaborators [170,31,101,28]have pushed forward the agreement between full nonlinear numerical results and results from perturbation theory for the collision of two black holes.This proves the power of the perturbation approach even in highly nonlinear problems while at the same time indicating its limits.In the concluding remarks of their pioneering paper on nonradial oscillations of neutron stars Thorne and Campollataro [202]described it as “just a modest introduction to a story which promises to be long,complicated and fascinating ”.The story has undoubtedly proved to be intriguing,and many authors have contributed to our present understanding of the pulsations of both black holes and neutron stars.Thirty years after these prophetic words by Thorne and Campollataro hundreds of papers have been written in an attempt to understand the stability,the characteristic frequencies and the mechanisms of excitation of these oscillations.Their relevance to the emission of gravitational waves was always the basic underlying reason of each study.An account of all this work will be attempted in the next sections hoping that the interested reader will ﬁnd this review useful both as a guide to the literature and as an inspiration for future work on the open problems of the ﬁeld.020406080100Time (M ADM )-0.3-0.2-0.10.00.10.20.3(l =2) Z e r i l l i F u n c t i o n Numerical solutionQNM fit Figure 1:QNM ringing after the head-on collision of two unequal mass black holes [29].The continuous line corresponds to the full nonlinear numerical calculation while the dotted line is a ﬁt to the fundamental and ﬁrst overtone QNM.In the next section we attempt to give a mathematical deﬁnition of QNMs.Living Reviews in Relativity (1999-2)K.D.Kokkotas and B.G.Schmidt6 The third and fourth section will be devoted to the study of the black hole and stellar QNMs.In theﬁfth section we discuss the excitation and observation of QNMs andﬁnally in the sixth section we will mention the more signiﬁcant numerical techniques used in the study of QNMs.Living Reviews in Relativity(1999-2)7Quasi-Normal Modes of Stars and Black Holes 2Normal Modes–Quasi-Normal Modes–Res-onancesBefore discussing quasi-normal modes it is useful to remember what normal modes are!Compact classical linear oscillating systems such asﬁnite strings,mem-branes,or cavitiesﬁlled with electromagnetic radiation have preferred time harmonic states of motion(ωis real):χn(t,x)=e iωn tχn(x),n=1,2,3...,(1) if dissipation is neglected.(We assumeχto be some complex valuedﬁeld.) There is generally an inﬁnite collection of such periodic solutions,and the“gen-eral solution”can be expressed as a superposition,χ(t,x)=∞n=1a n e iωn tχn(x),(2)of such normal modes.The simplest example is a string of length L which isﬁxed at its ends.All such systems can be described by systems of partial diﬀerential equations of the type(χmay be a vector)∂χ∂t=Aχ,(3)where A is a linear operator acting only on the spatial variables.Because of theﬁniteness of the system the time evolution is only determined if some boundary conditions are prescribed.The search for solutions periodic in time leads to a boundary value problem in the spatial variables.In simple cases it is of the Sturm-Liouville type.The treatment of such boundary value problems for diﬀerential equations played an important role in the development of Hilbert space techniques.A Hilbert space is chosen such that the diﬀerential operator becomes sym-metric.Due to the boundary conditions dictated by the physical problem,A becomes a self-adjoint operator on the appropriate Hilbert space and has a pure point spectrum.The eigenfunctions and eigenvalues determine the periodic solutions(1).The deﬁnition of self-adjointness is rather subtle from a physicist’s point of view since fairly complicated“domain issues”play an essential role.(See[43] where a mathematical exposition for physicists is given.)The wave equation modeling theﬁnite string has solutions of various degrees of diﬀerentiability. To describe all“realistic situations”,clearly C∞functions should be suﬃcient. Sometimes it may,however,also be convenient to consider more general solu-tions.From the mathematical point of view the collection of all smooth functions is not a natural setting to study the wave equation because sequences of solutionsLiving Reviews in Relativity(1999-2)K.D.Kokkotas and B.G.Schmidt8 exist which converge to non-smooth solutions.To establish such powerful state-ments like(2)one has to study the equation on certain subsets of the Hilbert space of square integrable functions.For“nice”equations it usually happens that the eigenfunctions are in fact analytic.They can then be used to gen-erate,for example,all smooth solutions by a pointwise converging series(2). The key point is that we need some mathematical sophistication to obtain the “completeness property”of the eigenfunctions.This picture of“normal modes”changes when we consider“open systems”which can lose energy to inﬁnity.The simplest case are waves on an inﬁnite string.The general solution of this problem isχ(t,x)=A(t−x)+B(t+x)(4) with“arbitrary”functions A and B.Which solutions should we study?Since we have all solutions,this is not a serious question.In more general cases, however,in which the general solution is not known,we have to select a certain class of solutions which we consider as relevant for the physical problem.Let us consider for the following discussion,as an example,a wave equation with a potential on the real line,∂2∂t2χ+ −∂2∂x2+V(x)χ=0.(5)Cauchy dataχ(0,x),∂tχ(0,x)which have two derivatives determine a unique twice diﬀerentiable solution.No boundary condition is needed at inﬁnity to determine the time evolution of the data!This can be established by fairly simple PDE theory[116].There exist solutions for which the support of theﬁelds are spatially compact, or–the other extreme–solutions with inﬁnite total energy for which theﬁelds grow at spatial inﬁnity in a quite arbitrary way!From the point of view of physics smooth solutions with spatially compact support should be the relevant class–who cares what happens near inﬁnity! Again it turns out that mathematically it is more convenient to study all solu-tions ofﬁnite total energy.Then the relevant operator is again self-adjoint,but now its spectrum is purely“continuous”.There are no eigenfunctions which are square integrable.Only“improper eigenfunctions”like plane waves exist.This expresses the fact that weﬁnd a solution of the form(1)for any realωand by forming appropriate superpositions one can construct solutions which are “almost eigenfunctions”.(In the case V(x)≡0these are wave packets formed from plane waves.)These solutions are the analogs of normal modes for inﬁnite systems.Let us now turn to the discussion of“quasi-normal modes”which are concep-tually diﬀerent to normal modes.To deﬁne quasi-normal modes let us consider the wave equation(5)for potentials with V≥0which vanish for|x|>x0.Then in this case all solutions determined by data of compact support are bounded: |χ(t,x)|<C.We can use Laplace transformation techniques to represent such Living Reviews in Relativity(1999-2)9Quasi-Normal Modes of Stars and Black Holes solutions.The Laplace transformˆχ(s,x)(s>0real)of a solutionχ(t,x)isˆχ(s,x)= ∞0e−stχ(t,x)dt,(6) and satisﬁes the ordinary diﬀerential equations2ˆχ−ˆχ +Vˆχ=+sχ(0,x)+∂tχ(0,x),(7) wheres2ˆχ−ˆχ +Vˆχ=0(8) is the homogeneous equation.The boundedness ofχimplies thatˆχis analytic for positive,real s,and has an analytic continuation onto the complex half plane Re(s)>0.Which solutionˆχof this inhomogeneous equation gives the unique solution in spacetime determined by the data?There is no arbitrariness;only one of the Green functions for the inhomogeneous equation is correct!All Green functions can be constructed by the following well known method. Choose any two linearly independent solutions of the homogeneous equation f−(s,x)and f+(s,x),and deﬁneG(s,x,x )=1W(s)f−(s,x )f+(s,x)(x <x),f−(s,x)f+(s,x )(x >x),(9)where W(s)is the Wronskian of f−and f+.If we denote the inhomogeneity of(7)by j,a solution of(7)isˆχ(s,x)= ∞−∞G(s,x,x )j(s,x )dx .(10) We still have to select a unique pair of solutions f−,f+.Here the information that the solution in spacetime is bounded can be used.The deﬁnition of the Laplace transform implies thatˆχis bounded as a function of x.Because the potential V vanishes for|x|>x0,the solutions of the homogeneous equation(8) for|x|>x0aref=e±sx.(11) The following pair of solutionsf+=e−sx for x>x0,f−=e+sx for x<−x0,(12) which is linearly independent for Re(s)>0,gives the unique Green function which deﬁnes a bounded solution for j of compact support.Note that for Re(s)>0the solution f+is exponentially decaying for large x and f−is expo-nentially decaying for small x.For small x however,f+will be a linear com-bination a(s)e−sx+b(s)e sx which will in general grow exponentially.Similar behavior is found for f−.Living Reviews in Relativity(1999-2)K.D.Kokkotas and B.G.Schmidt 10Quasi-Normal mode frequencies s n can be deﬁned as those complex numbers for whichf +(s n ,x )=c (s n )f −(s n ,x ),(13)that is the two functions become linearly dependent,the Wronskian vanishes and the Green function is singular!The corresponding solutions f +(s n ,x )are called quasi eigenfunctions.Are there such numbers s n ?From the boundedness of the solution in space-time we know that the unique Green function must exist for Re (s )>0.Hence f +,f −are linearly independent for those values of s .However,as solutions f +,f −of the homogeneous equation (8)they have a unique continuation to the complex s plane.In [35]it is shown that for positive potentials with compact support there is always a countable number of zeros of the Wronskian with Re (s )<0.What is the mathematical and physical signiﬁcance of the quasi-normal fre-quencies s n and the corresponding quasi-normal functions f +?First of all we should note that because of Re (s )<0the function f +grows exponentially for small and large x !The corresponding spacetime solution e s n t f +(s n ,x )is therefore not a physically relevant solution,unlike the normal modes.If one studies the inverse Laplace transformation and expresses χas a com-plex line integral (a >0),χ(t,x )=12πi +∞−∞e (a +is )t ˆχ(a +is,x )ds,(14)one can deform the path of the complex integration and show that the late time behavior of solutions can be approximated in ﬁnite parts of the space by a ﬁnite sum of the form χ(t,x )∼N n =1a n e (αn +iβn )t f +(s n ,x ).(15)Here we assume that Re (s n +1)<Re (s n )<0,s n =αn +iβn .The approxi-mation ∼means that if we choose x 0,x 1, and t 0then there exists a constant C (t 0,x 0,x 1, )such that χ(t,x )−N n =1a n e (αn +iβn )t f +(s n ,x ) ≤Ce (−|αN +1|+ )t (16)holds for t >t 0,x 0<x <x 1, >0with C (t 0,x 0,x 1, )independent of t .The constants a n depend only on the data [35]!This implies in particular that all solutions deﬁned by data of compact support decay exponentially in time on spatially bounded regions.The generic leading order decay is determined by the quasi-normal mode frequency with the largest real part s 1,i.e.slowest damping.On ﬁnite intervals and for late times the solution is approximated by a ﬁnite sum of quasi eigenfunctions (15).It is presently unclear whether one can strengthen (16)to a statement like (2),a pointwise expansion of the late time solution in terms of quasi-normal Living Reviews in Relativity (1999-2)11Quasi-Normal Modes of Stars and Black Holes modes.For one particular potential(P¨o schl-Teller)this has been shown by Beyer[42].Let us now consider the case where the potential is positive for all x,but decays near inﬁnity as happens for example for the wave equation on the static Schwarzschild spacetime.Data of compact support determine again solutions which are bounded[117].Hence we can proceed as before.Theﬁrst new point concerns the deﬁnitions of f±.It can be shown that the homogeneous equation(8)has for each real positive s a unique solution f+(s,x)such that lim x→∞(e sx f+(s,x))=1holds and correspondingly for f−.These functions are uniquely determined,deﬁne the correct Green function and have analytic continuations onto the complex half plane Re(s)>0.It is however quite complicated to get a good representation of these func-tions.If the point at inﬁnity is not a regular singular point,we do not even get converging series expansions for f±.(This is particularly serious for values of s with negative real part because we expect exponential growth in x).The next new feature is that the analyticity properties of f±in the complex s plane depend on the decay of the potential.To obtain information about analytic continuation,even use of analyticity properties of the potential in x is made!Branch cuts may occur.Nevertheless in a lot of cases an inﬁnite number of quasi-normal mode frequencies exists.The fact that the potential never vanishes may,however,destroy the expo-nential decay in time of the solutions and therefore the essential properties of the quasi-normal modes.This probably happens if the potential decays slower than exponentially.There is,however,the following way out:Suppose you want to study a solution determined by data of compact support from t=0to some largeﬁnite time t=T.Up to this time the solution is–because of domain of dependence properties–completely independent of the potential for suﬃciently large x.Hence we may see an exponential decay of the form(15)in a time range t1<t<T.This is the behavior seen in numerical calculations.The situation is similar in the case ofα-decay in quantum mechanics.A comparison of quasi-normal modes of wave equations and resonances in quantum theory can be found in the appendix,see section9.Living Reviews in Relativity(1999-2)K.D.Kokkotas and B.G.Schmidt123Quasi-Normal Modes of Black HolesOne of the most interesting aspects of gravitational wave detection will be the connection with the existence of black holes[201].Although there are presently several indirect ways of identifying black holes in the universe,gravitational waves emitted by an oscillating black hole will carry a uniqueﬁngerprint which would lead to the direct identiﬁcation of their existence.As we mentioned earlier,gravitational radiation from black hole oscillations exhibits certain characteristic frequencies which are independent of the pro-cesses giving rise to these oscillations.These“quasi-normal”frequencies are directly connected to the parameters of the black hole(mass,charge and angu-lar momentum)and for stellar mass black holes are expected to be inside the bandwidth of the constructed gravitational wave detectors.The perturbations of a Schwarzschild black hole reduce to a simple wave equation which has been studied extensively.The wave equation for the case of a Reissner-Nordstr¨o m black hole is more or less similar to the Schwarzschild case,but for Kerr one has to solve a system of coupled wave equations(one for the radial part and one for the angular part).For this reason the Kerr case has been studied less thoroughly.Finally,in the case of Kerr-Newman black holes we face the problem that the perturbations cannot be separated in their angular and radial parts and thus apart from special cases[124]the problem has not been studied at all.3.1Schwarzschild Black HolesThe study of perturbations of Schwarzschild black holes assumes a small per-turbation hµνon a static spherically symmetric background metricds2=g0µνdxµdxν=−e v(r)dt2+eλ(r)dr2+r2 dθ2+sin2θdφ2 ,(17) with the perturbed metric having the formgµν=g0µν+hµν,(18) which leads to a variation of the Einstein equations i.e.δGµν=4πδTµν.(19) By assuming a decomposition into tensor spherical harmonics for each hµνof the formχ(t,r,θ,φ)= mχ m(r,t)r Y m(θ,φ),(20)the perturbation problem is reduced to a single wave equation,for the func-tionχ m(r,t)(which is a combination of the various components of hµν).It should be pointed out that equation(20)is an expansion for scalar quantities only.From the10independent components of the hµνonly h tt,h tr,and h rr transform as scalars under rotations.The h tθ,h tφ,h rθ,and h rφtransform asLiving Reviews in Relativity(1999-2)13Quasi-Normal Modes of Stars and Black Holes components of two-vectors under rotations and can be expanded in a series of vector spherical harmonics while the components hθθ,hθφ,and hφφtransform as components of a2×2tensor and can be expanded in a series of tensor spher-ical harmonics(see[202,212,152]for details).There are two classes of vector spherical harmonics(polar and axial)which are build out of combinations of the Levi-Civita volume form and the gradient operator acting on the scalar spherical harmonics.The diﬀerence between the two families is their parity. Under the parity operatorπa spherical harmonic with index transforms as (−1) ,the polar class of perturbations transform under parity in the same way, as(−1) ,and the axial perturbations as(−1) +11.Finally,since we are dealing with spherically symmetric spacetimes the solution will be independent of m, thus this subscript can be omitted.The radial component of a perturbation outside the event horizon satisﬁes the following wave equation,∂2∂t χ + −∂2∂r∗+V (r)χ =0,(21)where r∗is the“tortoise”radial coordinate deﬁned byr∗=r+2M log(r/2M−1),(22) and M is the mass of the black hole.For“axial”perturbationsV (r)= 1−2M r ( +1)r+2σMr(23)is the eﬀective potential or(as it is known in the literature)Regge-Wheeler potential[173],which is a single potential barrier with a peak around r=3M, which is the location of the unstable photon orbit.The form(23)is true even if we consider scalar or electromagnetic testﬁelds as perturbations.The parameter σtakes the values1for scalar perturbations,0for electromagnetic perturbations, and−3for gravitational perturbations and can be expressed asσ=1−s2,where s=0,1,2is the spin of the perturbingﬁeld.For“polar”perturbations the eﬀective potential was derived by Zerilli[212]and has the form V (r)= 1−2M r 2n2(n+1)r3+6n2Mr2+18nM2r+18M3r3(nr+3M)2,(24)1In the literature the polar perturbations are also called even-parity because they are characterized by their behavior under parity operations as discussed earlier,and in the same way the axial perturbations are called odd-parity.We will stick to the polar/axial terminology since there is a confusion with the deﬁnition of the parity operation,the reason is that to most people,the words“even”and“odd”imply that a mode transforms underπas(−1)2n or(−1)2n+1respectively(for n some integer).However only the polar modes with even have even parity and only axial modes with even have odd parity.If is odd,then polar modes have odd parity and axial modes have even parity.Another terminology is to call the polar perturbations spheroidal and the axial ones toroidal.This deﬁnition is coming from the study of stellar pulsations in Newtonian theory and represents the type ofﬂuid motions that each type of perturbation induces.Since we are dealing both with stars and black holes we will stick to the polar/axial terminology.Living Reviews in Relativity(1999-2)K.D.Kokkotas and B.G.Schmidt14where2n=( −1)( +2).(25) Chandrasekhar[54]has shown that one can transform the equation(21)for “axial”modes to the corresponding one for“polar”modes via a transforma-tion involving diﬀerential operations.It can also be shown that both forms are connected to the Bardeen-Press[38]perturbation equation derived via the Newman-Penrose formalism.The potential V (r∗)decays exponentially near the horizon,r∗→−∞,and as r−2∗for r∗→+∞.From the form of equation(21)it is evident that the study of black hole perturbations will follow the footsteps of the theory outlined in section2.Kay and Wald[117]have shown that solutions with data of compact sup-port are bounded.Hence we know that the time independent Green function G(s,r∗,r ∗)is analytic for Re(s)>0.The essential diﬃculty is now to obtain the solutions f±(cf.equation(10))of the equations2ˆχ−ˆχ +Vˆχ=0,(26) (prime denotes diﬀerentiation with respect to r∗)which satisfy for real,positives:f+∼e−sr∗for r∗→∞,f−∼e+r∗x for r∗→−∞.(27) To determine the quasi-normal modes we need the analytic continuations of these functions.As the horizon(r∗→∞)is a regular singular point of(26),a representation of f−(r∗,s)as a converging series exists.For M=12it reads:f−(r,s)=(r−1)s∞n=0a n(s)(r−1)n.(28)The series converges for all complex s and|r−1|<1[162].(The analytic extension of f−is investigated in[115].)The result is that f−has an extension to the complex s plane with poles only at negative real integers.The representation of f+is more complicated:Because inﬁnity is a singular point no power series expansion like(28)exists.A representation coming from the iteration of the deﬁning integral equation is given by Jensen and Candelas[115],see also[159]. It turns out that the continuation of f+has a branch cut Re(s)≤0due to the decay r−2for large r[115].The most extensive mathematical investigation of quasi-normal modes of the Schwarzschild solution is contained in the paper by Bachelot and Motet-Bachelot[35].Here the existence of an inﬁnite number of quasi-normal modes is demonstrated.Truncating the potential(23)to make it of compact support leads to the estimate(16).The decay of solutions in time is not exponential because of the weak decay of the potential for large r.At late times,the quasi-normal oscillations are swamped by the radiative tail[166,167].This tail radiation is of interest in its Living Reviews in Relativity(1999-2)。

高一人类与宇宙英语阅读理解30题

高一人类与宇宙英语阅读理解30题1<背景文章>Since ancient times, humans have been gazing at the sky with wonder and curiosity, eager to understand the vast universe that surrounds us. The exploration of the universe has been a long and arduous journey filled with remarkable achievements and countless challenges.One of the earliest important events in the history of space exploration was the launch of Sputnik 1 by the Soviet Union in 1957. This small satellite marked the beginning of the Space Age. It was a shock to the world and led to an intense space race between the United States and the Soviet Union. Subsequently, in 1961, Yuri Gagarin became the first human to orbit the Earth, another milestone in human space exploration.The United States made significant contributions as well. The Apollo program aimed at landing humans on the Moon. In 1969, Apollo 11 achieved this goal when Neil Armstrong took his first step on the lunar surface, with his famous words, "That's one small step for man, one giant leap for mankind." This event not only demonstrated the technological prowess of humanity but also deepened our understanding of the Moon and the solar system.However, exploring the universe is not without difficulties. The costof space exploration is extremely high. Building rockets, satellites, and space stations requires a large amount of capital investment. Moreover, the space environment is harsh. Astronauts face various risks such as radiation, microgravity, and potential equipment failures.Despite these challenges, the exploration of the universe has profound significance. It helps us expand our knowledge of science. For example, we can study celestial bodies to learn more about physics, astronomy, and geology. It also inspires future generations to pursue careers in science, technology, engineering, and mathematics (STEM). Additionally, exploring the universe may lead to the discovery of new resources and even new habitats for humanity in the future.1. <问题1>What was the significance of Sputnik 1?A. It was the first satellite to land on the Moon.B. It marked the start of the Space Age.C. It carried the first human into space.D. It was the first American satellite.答案：B。

行星第1季_左英右中_单词备注版

行星第1季S01E01The night sky is ablaze with stars...静谧的夜空中繁星闪烁ablaze:/ә'bleiz/TOF a.着火的,闪亮的,激昂的adv.着火,闪耀..hundreds of billions in our galaxy alone...单纯我们银河系里的恒星就有数千亿颗billion:/'biljәn/num.十亿,十亿个galaxy:/'gælәksi/GRE CET6TEM4TEM8TOF n.银河,星系,一群(显赫的人物)[电]银河系..many larger,brighter and more majestic than our其中有些比太阳更大更亮也更辉煌sun.brighter:/braitə/a.聪明的(bright的比较级);光亮的;辉煌的;前途光明的majestic:/mә'dʒestik/GRE a.宏伟的,庄严的On the scale of galaxies and stars,the planets of our从银河系和恒星的角度说太阳系中的行星solar systemscale:/skeil/GRE CET6CET4TEM8TOF n.刻度,衡量,比例,比例尺,数值范围,等级,规模,天平,秤,鳞,积垢vt.依比例决定,攀登,测量,绘制,刮鳞,使生垢,过秤vi.剥落,生水垢,重量为,攀登,衡量[计]刻度system:/'sistәm/CET4TEM4n.系统,体系,制度,方式,秩序,分类原则[计]系统;体制;体系solar:/'sәulә/CET4TEM4TOF a.太阳的,日光的,源自太阳的[医]太阳的;腹腔丛的are little more than grains of sand caught momentarily不过是阳光偶然掠过的grain:/grein/GRE CET6CET4TOF n.谷粒,颗粒,谷类,纹理,本质v.(使)成谷粒momentarily:/'mәumәntәrili/adv.暂时地,立刻,随时地in the light of the sun.一颗沙粒12S01E01 But on those motes of dust,for over four billion years,但是40多亿年来这些微尘之上却写就了mote:/mәut/GRE n.尘埃,微粒great stories have played out unseen.许多鲜为人知的壮丽史篇unseen:/.ʌn'si:n/a.未被看见的,看不见的Stories of worlds born...这是关于行星的诞生..and worlds lost.还有消亡的故事Planets forged amongst the calm...行星在沉寂平静中孕育forge:/fɒ:dʒ/GRE CET6TEM4TOF n.熔炉,铁工厂vt.打制,锻造,伪造vi.锻造,伪造amongst:/ә'mʌŋst/CET4prep.在...当中,在...之间,在...之中calm:/kɑ:m/CET4TEM4n.平稳,风平浪静a.平静的,冷静的vi.平静下来,镇静vt.使平静..and the chaos.在混沌中成形chaos:/'keiɒs/GRE TOF n.大混乱,混沌[化]混沌;浑沌Their destinies more entwined than we ever imagined.它们的命运纠缠关联超乎我们的想象destiny:/'destini/CET6TEM4TOF n.命运,定数entwine:/in'twain/GREv.(使)缠住,(使)盘绕,(使)纠缠We know this...我们知道这些..because in the last few decades...是因为在过去的数十年间decade:/'dekeid/CET6CET4TEM4TOF n.十年,十..we’ve sent spacecraft to all seven...我们向太阳系中地球以外的其它7大行星spacecraft:/'speiskræft/n.航天飞船..of the worlds beyond our own.都发射过探测器These are the stories that they return to Earth,我们这里要讲述的就是它们发送回地球的故事the stories of the planets.也就是行星的故事For the first few million years after the sun formed,在太阳诞生后的最初数百万年里3there were no planets to see it rise...它的周围还没有行星出现..just clouds of dust and the gas...只有无尽的尘埃和气体..the leftovers from the birth of the sun.leftovers://n.吃剩的食物这些是太阳诞生时残留的材料Over tens of millions of years,the dust began to stick together...stick:/stik/CET4TEM4TOF n.棍,棒,刺,枯枝,茎,条状物vt.插进,刺入,钉住,伸出,粘贴,停止vi.粘住,停留,坚持,陷住,伸出经过上千万年的时间这些尘埃开始慢慢结合聚集..and form the first rocks.形成了最早的岩石Eventually,gravity assembled the rockseventually:/i'ventʃuәli/CET4TEM4adv.最后,终于gravity:/'græviti/GRE CET4TEM4TOF n.地心引力,重力[化]重力assemble:/ә'sembl/GRE CET6CET4TEM4TOF vt.集合,收集,装配vi.集合[计]汇编最终这些岩石在引力作用下to create planetary embryos...create:/kri:'eit/CET4TEM4vt.创造,建造,引起,任命planetary:/'plæni-tri/TOF a.行星的,流浪的,迁移不定的,地球上的,现世的embryo:/'em-briәu/TOF n.胚胎,胎儿,胚芽[医]胚,胚胎创造出了行星的胚胎..that in time formed the four closest planets to thesun.随后催生出了距离太阳最近的4颗行星Today,Mercury is the closest of all,如今水星成为离太阳最近的行星enduring the sun’s full glare.endure:/in'djuә/GRE CET6CET4TEM4TOF vt.忍受,忍耐,容忍,耐vi.(正式)持久,持续[计]仍能工作,继续工作glare:/glєә/GRE CET6CET4TEM4TOF n.闪耀光,刺眼vi.发眩光,瞪视vt.瞪眼表示承受着强烈的太阳光照Further out...从水星继续向外..lies Venus...是金星4S01E01 ..chocked by a thick atmosphere.它的表面包裹着浓密的大气层chock:/tʃɒk/n.塞块,木楔,楔形木垫vt.用楔子垫阻,收放定盘上adv.满满地atmosphere:/'ætmәsﬁә/CET6CET4TOF n.大气,空气,气氛[医]大气;大气压Then Venus’s neighbour,Earth.金星向外的邻居就是我们的地球And farthest of all,Mars...4颗行星中距离太阳最远的是火星farthest:/'fɑ:ðist/a.最远的,最久的adv.最远,far的最高级..a cold desert world.一个寒冷荒凉的世界Together,they formed the only rocky so-called terres-它们共同构成了太阳系中仅有的岩石行星trial planetsrocky:/'rɒki/TOF a.岩石的,多石的,像岩石的,无情的,摇动的,摇晃的terrestrial:/tә'restriәl/GRE TOF n.地球上的人a.地球的,陆生的,陆地的,人间的in the solar system.即“类地行星”solar:/'sәulә/CET4TEM4TOF a.太阳的,日光的,源自太阳的[医]太阳的;腹腔丛的system:/'sistәm/CET4TEM4n.系统,体系,制度,方式,秩序,分类原则[计]系统;体制;体系And of the four...在这4颗行星中..one is unique.有一颗显得独一无二unique:/ju:'ni:k/GRE CET6CET4TOF a.独一无二的,独特的,稀罕的Just look at this...大家只要放眼四周..and listen to it.聆听一番This is what a planet looks and sounds like一颗行星在经历了5after four billion years of evolution by natural selec-tion.billion:/'biljәn/num.十亿,十亿个selection:/si'lekʃәn/CET4TEM4TOF n.选择,选文,精选品[医]选择,淘汰evolution:/.i:vә'lu:ʃәn/CET6CET4 TEM4n.进化,发展,进展,(气体)放出,开方[医]进化,演化,旋出40亿年的自然进化后便有了现在的音容外貌There is nowhere else in the solar system太阳系中再也找不到that looks and sounds like this,与之相似的行星了which is interesting,when you think about it,这一点思索起来很有意思because all the planets and moons and are made out of the same stuff-因为所有的行星和卫星都是由相同物质构成的they’re carbon,nitrogen,oxygen,iron.carbon:/'kɑ:bәn/CET4TOF n.碳,副本,复写纸[化]碳nitrogen:/'naitrәdʒәn/CET4TOF n.氮[化]氮N-2oxygen:/'ɒksәdʒәn/CET6TEM4TOF n.氧[化]氧O-2包括碳氮氧铁All those atoms were present in the cloud that col-lapsedatom:/'ætәm/CET4TEM4TOF n.原子,核能,微粒,微量[计]原子col-lapse:/kә'læps/GRE CET6CET4TEM4TEM8TOF n.崩溃,倒塌,虚脱vi.倒塌,崩溃,瓦解vt.使倒塌,折叠[计]折叠45亿年前坍缩形成太阳系的尘埃云里to form the solar system,four-and-a-half billion yearsago.就包含所有这些原子And yet Earth appears to be exceptional-exceptional:/ik'sepʃәnәl/GRE CET6TEM4TEM8TOF a.例外的,异常的,特别的然而地球却显得格外独特a lone living planet in an otherwise desolate solar sys-tem.lone:/lәun/TOF a.孤单的,孤立的,单身的,寂寞的desolate:/'desәlәt/GRE TEM4TOF a.荒凉的它是荒芜太阳系中唯一一颗有生命的行星6S01E01 So what is it that makes this place so special?到底是什么原因让地球显得如此特别呢Is it fate?Is it chance?是命中注定还是巧合fate:/feit/n.命运,运气vt.注定These are important questions这些问题非常重要because Earth is the only place we know of因为地球是目前我们人类已知的where the most complex phenomena in the universe宇宙中存在的最复杂的现象exists,complex:/kәm'pleks/CET6CET4TEM4TOF n.综合体,情结,络合物a.复杂的,组合的phenomenon:/ﬁ'nɒminәn/CET6CET4TEM4TOF n.现象,迹象,表现,奇迹,奇才[化]现象universe:/'ju:nivә:s/CET6CET4TOF n.宇宙,星系,(思想等)范围the thing that brings meaning to the universe-life.它赋予了宇宙的意义那就是生命Earth is a special world in our solar system地球是太阳系中一个特别的世界and perhaps even for thousands of light years beyond.甚至在数千光年的范围内也是如此Our world certainly has unique properties.我们的世界确实有其独特之处property:/'prɒpәti/CET6CET4TOF n.财产,所有权,性质,属性[计]属性It’s the right size and distance from the sun地球的大小适当与太阳的距离恰到好处distance:/'distәns/CET4TEM4n.距离,远方,遥远[计]位距to have retained an atmosphere that’s protected its这使它在数十亿年里能够保持大气层oceansretain:/ri'tein/GRE CET6CET4TEM4TOF vt.保持,保有,留住,记得,付定金聘请[经]保留,留存atmosphere:/'ætmәsﬁә/CET6CET4TOF n.大气,空气,气氛[医]大气;大气压of life-giving water for billions of years.进而保护了地球上赋予生命的海洋But as we’ve left the blue planet,可当我们离开这颗蓝色星球7and explored our sister worlds...explore:/ik'splɒ:/CET6CET4TEM4TOF v.探险,探测,探究去探索其它姊妹行星时..we’ve discovered that each appears to have had a mo-ment我们发现每颗类地行星似乎都有过when it enjoyed almost Earth-like conditions.酷似地球的环境Every one of our rocky neighbours has a story of whatmight have been.rocky:/'rɒki/TOF a.岩石的,多石的,像岩石的,无情的,摇动的,摇晃的每颗类地行星都曾有过生命诞生的机会Mercury is a small,tortured world.tortured:/ˈtɔ:tʃəd/v.使痛苦(torture的过去式和过去分词);使苦恼;使焦急水星是一颗备受摧残的小个行星More than any other planet,数十亿年的光阴中it’s endured the unflinching glare of the sun for billions of years.endure:/in'djuә/GRE CET6CET4TEM4TOF vt.忍受,忍耐,容忍,耐vi.(正式)持久,持续[计]仍能工作,继续工作unﬂinching:/.ʌn'ﬂintʃiŋ/a.不畏惧的,不退缩的,不畏缩的glare:/glєә/GRE CET6CET4TEM4TOF n.闪耀光,刺眼vi.发眩光,瞪视vt.瞪眼表示它始终承受着比其它所有行星更加狂暴的太阳炙烤Mercury is a world of mystery and apparent contradic-tions.mystery:/'mistәri/CET4TEM4n.秘密,神秘,奥秘apparent:/ә'pærәnt/CET4TEM4TOF a.清晰可见的,显然的,表面上的[电]外在的contradiction:/.kɒntrә'dikʃәn/CET6CET4n.反驳,矛盾[法]矛盾,否认,反驳水星是个充满谜团与矛盾的世界It’s in quite an elliptical orbit,elliptical:/i'liptikәl/GRE TEM8TOF a.椭圆的[医]椭圆形的orbit:/'ɒ:bit/CET6CET4TEM4TOF n.轨道,常轨,眼眶vt.绕...轨道而行vi.进入轨道,盘旋它的运行轨道呈椭圆形8S01E01 which means it can be as far away from the sun as70这意味着它在远日点离太阳是7000万公里million km,km://[医]千米,公里but as close as46million.近日点却只有4600万公里That means that temperatures at midday所以正午时temperature:/'temprәtʃә/CET4TEM4TOF n.温度,发烧,热度[化]温度midday:/'middei/n.正午,中午a.正午的can rise to430degrees Celsius on the surface,水星的地表温度高达430摄氏度degree:/di'gri:/CET4TEM4n.程度,度数,学位,度[医]度,程度celsius:/'selsiәs/TOF a.摄氏的surface:/'sә:ﬁs/n.面,表面,水面,外表,平面a.表面的,外观的,肤浅的,水面上的vt.使成平面,使浮出水面vi.浮出水面,呈现,在地面上工作but,at night,because it’s a small planet and it’s got no到了夜晚因为它很小本身没有大气层atmosphere,temperatures fall to minus170degrees.温度会骤降至零下170摄氏度minus:/'mainәs/CET4TEM4n.负号,不足a.减的,负的,阴性的prep.减,缺[计]负差It’s also locked into what’s called the spin-orbit reso-它也受到了所谓“轨旋共振”的困扰nance,spin:/spin/GRE CET4TEM4TOF n.旋转,自旋,疾驰,情绪低落vt.纺织,纺,使旋转,编造vi.纺纱,吐丝,作茧,结网,旋转,自旋,疾驰resonance:/'rezәnәns/TOF n.共鸣,回声,反响,谐振,共振[化]共振;共鸣which means the planet spins precisely three times on换句话说水星每公转两周its axisprecisely:/pri'saisli/adv.精确地,明确地,刻板地,拘泥地,正好,恰恰,对,正是如此,确实如此,不错axis:/'æksis/GRE CET6CET4TOF n.轴[计]坐标轴for every two orbits就可以完成自转三周9and that in turn means that its day is twice as long as its year.这意味着水星上的一天几乎相当于两个水星年That means that I could walk over the surface like this也就是说我以每小时3.2公里的速度about2mph在水星表面行走and keep the sun at the same point in the sky.太阳在空中的位置将始终不变I could stroll in eternal twilight.stroll:/strәul/GRE CET6TOF n.闲逛,漫步v.闲逛,漫步eternal:/i'tә:nl/GRE CET6TEM4TEM8TOF a.永恒的,永远的,不灭的twilight:/'twailait/n.暮光,曙光,黎明,黄昏,微光,朦胧状态a.微明的我能在水恒的暮色中一直走下去Mercury is the least explored of the inner rocky worlds...水星是迄今为止人类探索最少的太阳系内层类地行星..because getting to a planet in such a strange oval-shaped orbit,oval:/'әuvәl/n.椭圆形a.卵形的,椭圆形的因为水星的公转轨道呈奇特的椭圆形so close to the sun...距离太阳太近..is a tremendous challenge.tremendous:/tri'mendәs/GRE CET6CET4TEM4TOF a.巨大的,非常的,可怕的challenge:/'tʃælindʒ/CET6CET4TEM4n.挑战,盘问vt.向...挑战,要求,怀疑vi.挑战,对(证据等)表示异议人类探测水星存在巨大挑战543Five,four,three,main engine start,two,one and zero.engine:/'endʒin/CET6CET4TEM4TOF n.引擎,发动机,机车vt.安装发动机于引擎点火210And lift off of Messenger on Nasa’s mission to Mer-cury...lift:/lift/CET4TEM4n.举起,帮助,昂扬,电梯vt.升高,提高,鼓舞,清偿,空运,举起,剽窃vi.升起,消散,耸立mission:/'miʃәn/CET6CET4 TEM4TOF n.任务,代表团,使命,传教团vt.派遣,向...传教美国国家航空航天局的“信使”号探测器升空10S01E01 ..a planetary enigma in our inner solar system.它是太阳系中一颗充满迷雾的行星planetary:/'plænitri/TOF a.行星的,流浪的,迁移不定的,地球上的,现世的enigma:/i'nigmә/TEM8TOF n.谜,费解的事物system:/'sistәm/CET4TEM4n.系统,体系,制度,方式,秩序,分类原则[计]系统;体制;体系solar:/'sәulә/CET4TEM4TOF a.太阳的,日光的,源自太阳的[医]太阳的;腹腔丛的Now going through the sound barrier.现在探测器穿越音障barrier:/'bæriә/GRE CET6CET4TEM4TOF n.障碍,栅栏[化]势垒;阻片;阻挡层A direct route to Mercury is impractical.直接飞向水星明显不切实际route:/ru:t/CET4TEM4n.路径,途径,路线vt.确定路线,按规定路线发送[计]传递,路由设定程序impractical:/im'præktikәl/a.不切实际的,不能实行的,不现实的,不合情理的Now going through the period of maximum dynamic现在要进入最大动压阶段pressure.maximum:/'mæksimәn/CET6CET4TEM4TOF n.极点,最大量,极大a.最高的,最大的,最大极限的[计]最大值dynamic:/dai'næmik/GRECET4TEM4 a.动态的,有活力的,有力的,动力的,不断变化的n.动力,动态[计]动态的pressure:/'preʃә/CET6CET4TEM4TOF n.压,榨,按,强制,压力,压迫,压强vt.迫使,使增压,密封A spacecraft would arrive with so much speed探测器抵达目的地时的速度可能太大spacecraft:/'speiskræft/n.航天飞船that it would need vast amounts of fuel to slow down需要大量燃料用于减速vast:/vɑ:st/CET6CET4TOF a.巨大的,广大的,非常的,大量的fuel:/'fjuәl/CET6CET4n.燃料,木炭vt.加燃料,供燃料vi.得到燃料and enter orbit around Mercury.并进入绕水星轨道We just had spacecraft separation.火箭分离成功separation:/.sepә'reiʃәn/n.分离,分居,缺口,退职[化]分离11So Messenger controlled its trajectorytrajectory:/trә'dʒektri/GRE n.轨道,弹道,轨线[化]轨道“信使”号探测器by stepping from one planet to the next,以各行星作为跳板控制飞行轨道using gravity to slow itself,gravity:/'græviti/GRE CET4TEM4TOF n.地心引力,重力[化]重力同时借助引力降低速度spiralling inwards towards its target.spiral:/'spairәl/CET6TOF n.螺旋形之物,螺线a.螺旋形的,盘旋的vi.螺旋形下降,螺旋形上升,螺旋形行进vt.使螺旋形行进inwards:/'inwәdz/adv.在内部,向中心,向内,内里[经]进口税towards:/tә'wɔ:dz/prep.向,对于,为了target:/'tɑ:git/CET6CET4TEM4n.目标,靶子,指标vt.对准,订指标呈螺旋形靠近目标Even so,Messenger approached Mercury at such high speedapproach:/ә'prәutʃ/GRE CET6CET4TEM4TOF n.接近,入门vt.接近,近似,找...商量vi.靠近即便如此“信使”号接近水星的速度依旧很高that it was forced to fly past the planet three times...不得不三次飞过水星..slowing on each pass...通过每次掠过实现减速..until,after almost seven years of flawless navigation,ﬂawless:/'ﬂɒ:lis/a.无瑕疵的,无缺点的[化]无裂纹的;无裂缝的naviga-tion:/.nævi'geiʃәn/CET6CET4TEM4TOF n.航行,航海,导航[经]航空,航海,航船经过将近7年准确无误的飞行后it arrived safely in orbit.orbit:/'ɒ:bit/CET6CET4TEM4TOF n.轨道,常轨,眼眶vt.绕...轨道而行vi.进入轨道,盘旋“信使”号终于安全进入绕水星轨道Messenger set about its mission to map Mercury’s sur-face...surface:/'sә:ﬁs/n.面,表面,水面,外表,平面a.表面的,外观的,肤浅的,水面上的vt.使成平面,使浮出水面vi.浮出水面,呈现,在地面上工作“信使”号探测器的使命是探测水星表面12S01E01..and began revealing the secrets of the most cratered planetreveal:/ri'vi:l/CET6CET4TEM4TOF vt.露出,显示,透露,揭露,泄露, (神)启示n.窗侧,门侧cratered:/k'reɪtərd/a.有坑洞的,多坑的v.火山口(crater的过去分词);弹坑等同时它将以前所未有的特写镜头揭开这颗太阳系中in the solar system in exquisite new detail.exquisite:/'ekskwizit/GRE CET6TEM8TOF a.精致的,细腻的,敏锐的陨石坑最密集行星的秘密Messenger was able to do much more“信使”号探测器能做的than just take images of Mercury’s surface.不只是拍摄水星表的照片而已By tracking radio signals emitted by the spacecraft,track:/træk/GRE CET4TEM4n.轨迹,足迹,径迹,小道,轨道,磁轨,途径vt.循路而行,追踪,通过,用纤拉vi.追踪,留下足迹,沿轨道运行[计]跟踪emit:/i'mit/GRE CET4TEM4TOF vt.发出,放射,发表(意见等),散发,发行[化]放射通过追踪探测器发射的无线电信号we’re able to see very slight changes in the orbital pathslight:/slait/GRE CET6CET4TEM4TEM8TOF n.轻蔑,怠慢a.轻微的,纤细的,脆弱的,苗条的vt.轻视,忽略,怠慢orbital:/'ɒ:bitәl/TOF a.轨道的,眼眶的[化]轨道我们能够从地球上看到绕水星轨道的around Mercury,as seen from Earth,所有细微变化and that allows us to map out Mercury’s gravitationalfield.gravitational:/.grævi'teiʃәnәl/GRE TOF a.重力的由此绘制出水星的引力场There are also instruments that allow usinstrument:/'instrumәnt/CET6CET4TEM4TOF n.工具,手段,仪器[化]仪器探测器上的仪器to see how the planet wobbles aroundwobble:/'wɒbl/GRE TEM8n.摆动,摇晃,不稳定,抖动vi.摇晃,摇摆,游移不定vt.使摇摆,使颤动还能让我们看到水星自转时的13 as it spins on its axis.晃动情况spin:/spin/GRE CET4TEM4TOF n.旋转,自旋,疾驰,情绪低落vt.纺织,纺,使旋转,编造vi.纺纱,吐丝,作茧,结网,旋转,自旋,疾驰axis:/'æksis/GRE CET6CET4TOF n.轴[计]坐标轴And putting all these measurements together我们把所有测量数据集中起来measurement:/'meʒәdmәnt/n.尺寸,度量,度量单位[计]度量,度量单位allows us to take a cross section through the planet,就能得到水星的横截面section:/'sekʃәn/CET4TOF n.区段,部分,区域,节,截面,处,科,区,扇区vt.把...分段,把...切片vi.被切成片[计]扇区to see what it’s made of.进而判断出它的构成And when we do that,we find something very strange.结果我们取得了某种奇怪的发现Mercury’s core extends out about85%水星的内核占据了extend:/ik'stend/GRE CET4TEM4TOF v.扩充,延伸,伸展,扩大[计]扩展from the centre of the planet to the surface.从其核心到地表大约85％的范围centre:/'sentә/n.中心,中心点,中锋a.中央的,位在正中的vt.集中,定中心vi.居中It’s almost entirely an exposed planetary core.这几乎就是一颗完全暴露的行星核心entirely:/in'taiәli/adv.完全,全然,一概planetary:/'plænitri/TOF a.行星的,流浪的,迁移不定的,地球上的,现世的expose:/ik'spәuz/CET6CET4TEM4vt.使暴露,使曝光,揭穿,陈列[医]暴露,露置It’s as if the rocks of the surface were smashed away就好像水星表面的岩石外衣smash:/smæʃ/CET6TEM4TOF n.打碎,粉碎,打碎时哗啦声,猛击,扣球,杀球,经营失败,破产,硬币,假硬币a.非常轰动的,了不起的vt.打碎,粉碎,击溃,使破产,使裂变,使用假硬币vi.碎裂,猛撞,破产,扣球,杀球adv.轰隆一声,哗啦一声and removed at some point in its past.在过去被粉碎剥离了一样14S01E01 And there was more.探测结果还不止于此The tiny probe began detecting chemical elements inconcentrationsprobe:/prәub/GRE CET6TEM4TEM8TOF n.探索,调查,探针,探测器v.用探针探测,调查,探索detect:/di'tekt/CET6CET4TEM4TOF vt.发现,察觉,探测[法]发现,查明,探测chemical:/'kemikl/n.化学药品a.化学的,化学上用的concentration:/.kɒnsәn'treiʃәn/CET6CET4TOF n.集中,专心[化]浓度;浓缩element:/'elimәnt/CET6CET4TEM4TOF n.元件,元素,要素[计]部分;成分;单元;码元;元件;元素;单元“信使”号在这颗距离太阳最近的水星上that no-one had thought possible this close to the sun.还探测到许多化学元素的浓度简直出人意料The discovery of relatively large concentrations of ele-mentsrelatively:/'relәtivli/CET4TOF adv.相对地,比较地,相当地,相关地[计]相对地水星表面居然有含量较高的like sulphur and potassium on Mercury’s surfacesulphur:/'sʌlfә/n.硫,硫磺[化]硫potassium:/pә'tæsiәm/TOF n.钾[化]钾K硫和钾这类元素was a huge surprise.这项发现确实让人大吃一惊If you think back to the time when the planets wereforming,要知道在行星形成之时you don’t expect high concentrations of those elements close to the sun,水星在如此靠近太阳的公转轨道上不太可能出现where Mercury orbits today,because they’re so-called volatile elements.orbit:/'ɒ:bit/CET6CET4TEM4TOF n.轨道,常轨,眼眶vt.绕...轨道而行vi.进入轨道,盘旋volatile:/'vɒlәtail/GRE TEM8TOF a.挥发性的,可变的,不稳定的,飞行的,轻快的,爆炸性的n.有翅动物,挥发物[计]易失的如此高含量的化学元素因为它们是挥发性元素15 They boil away easily,很容易蒸发boil:/bɒil/n.煮沸,沸腾,疖v.煮沸,激动so you only find high concentrations further out,通常只有在距太阳较远的寒冷区域in the colder reaches of the solar system.才会达到如此高的含量colder://a.更冷的,越来越冷的（cold的比较级）So Mercury is an enigma所以水星确实是个谜enigma:/i'nigmә/TEM8TOF n.谜,费解的事物and discoveries like these have forced us to completely类似这些发现促使我们不得不重新思考rethinkrethink:/ri:'θiŋk/v.再想,重想our theories about the formation of the planet.有关行星形成的理论theory:/'θiәri/CET4TEM4n.理论,学说,原理,意见,推测[化]理论formation:/fɒ:'meiʃәn/GRE CET4TOF n.形成,构造,编队[医]形成,结构Just a few million years after its formation,在形成后的数百万年里Mercury was still seething with the heat of its violent水星仍旧在肆意喷吐剧烈诞生时的热量birth.seethe:/si:ð/GRE vi.冒泡,沸腾vt.使煮沸,使浸透n.翻腾heat:/hi:t/n.热,热度,体温,高潮vi.加热,激昂,加剧vt.把...加热,使激动violent:/'vaiәlәnt/CET6CET4TOF a.暴力的,猛烈的,激烈的,极端的,凶暴的Slowly,it cooled and a crust formed.之后它渐渐冷却地壳形成crust:/krʌst/GRE CET4TEM4TOF n.外壳,坚硬外皮,面包皮vt.盖以硬皮vi.结硬皮Over time,the crust became enriched随着时间推移地壳中吸收了enriched:/in'ritʃt/a.浓缩的；强化的16S01E01in the volatile elements that were escaping Mercury’sinterior.interior:/in'tiәriә/CET4TEM4TOF n.内部,内政a.内部的,心灵的,内地的,内政的从水星内核逃逸出的挥发性元素But this could only happen if Mercury started out但发生这种情况的唯一可能是not in the position we see it today...水星诞生之时处于更加远离太阳的地方..but much further out.而不会是现在的位置We now think Mercury was born perhaps170million kmkm://[医]千米,公里我们现在认为水星诞生于离太阳1.7亿公里的地方further away,close to the orbit of Mars...位置靠近火星的公转轨道..a place where,if it had stayed,如果它还待在原地的话its destiny could have been very different.destiny:/'destini/CET6TEM4TOF n.命运,定数水星的命运或许会截然不同But it wasn’t to be.但事实并非如此The young planetary embryo was ripped from its promising positionembryo:/'embriәu/TOF n.胚胎,胎儿,胚芽[医]胚,胚胎rip:/rip/GRE CET6n.裂痕,破绽,拉裂,浪子,巨浪vi.被拉开,裂开,猛冲vt.撕,扯,劈promising:/'prɒmisiŋ/CET6CET4TEM4TOF a.有希望的,前途有望的[经]有希望的稚嫩的水星胚胎早在成熟之前就在引力作用下long before it could mature.mature:/mә'tjuә/GRE CET6CET4TEM4TOF a.成熟的,到期的,充分考虑的vt.使成熟vi.成熟,到期产生了偏离Today,it’s hard to imagine the planets我们很难想象in orbits other than the ones we see in the night sky.夜空中的行星所在的轨道会发生变化17They feel eternal,permanent.eternal:/i'tә:nl/GRE CET6TEM4TEM8TOF a.永恒的,永远的,不灭的permanent:/'pә:mәnәnt/GRE CET6CET4TEM4TOF a.永久的,不变的,固定的,持久的n.烫发[计]永久的它们似乎是永恒不变的存在It’s natural to think of the solar system我们往往会把太阳系看作是as a piece of celestial clockwork,almost like a Swisswatch.celestial:/si'lestjәl/GRE TOF a.天的,天国的,天空的[法]天的,天空的,天国的Swiss:/swis/n.瑞士人,瑞士腔调a.瑞士的,瑞士风格的clockwork:/'klɒkwә:k/n.钟表装置,发条装置[电]时钟开关瑞士手表一样精密的天体表盘So if we knew where all the planets were at some point in time,如果我们已知所有行星在某个时间点的位置let’s say today,then we could imagine calculating比如今天我们就能计算出exactly where they’re going to be at any point in time.exactly:/ig'zæktli/CET4TEM4adv.确切地,精确地,恰好,完全地,确实,恰恰正是,确实如此它们任何时间的确切位置Now,that is true if there’s only one planet and one star.如果只是一颗行星和一颗恒星这是没问题的So imagine that’s the sun and this is Mercury.想象一下那是太阳这是水星Now,we know the gravitational force between Mer-cury and the sun.gravitational:/.grævi'teiʃәnәl/GRE TOF a.重力的我们知道太阳和水星间的引力And,indeed,if that’s all there is,如果只是这样then we can calculate its orbit around the sun我们就能以最大的精确度18S01E01 with essentially infinite precision.计算出它围绕太阳运行的轨道essentially:/i'senʃәli/adv.本质上,本来inﬁnite:/'inﬁnit/CET6CET4TEM4TEM8n.无限,神 a.无穷的,无限的,极大的precision:/pri'siʒәn/CET4TEM4n.精密,精确,精确度,精度a.精密的,精确的[计]精度But add in one more planet,let’s say Jupiter over there.可是如果再加一颗行星比如说那边是木星Now there’s a gravitational force between all three of很显然这三个天体间都存在引力these objectsand it turns out that,even in principle,那么原则上说principle:/'prinsipl/GRE CET6CET4TEM4TOF n.原则,原理,主义[化]原理it is not possible to calculate exactly我们根本不可能准确计算出where they’re all going to be in the future它们将来的位置or where they were at some point in the past.或者过去某个时间点的具体位置This means that any uncertainty,even of a few metres这意味着以我们对行星位置的了解uncertainty:/.ʌn'sә:tnti/TEM4n.不确定,不可靠,不确定的事物[化]不确定度metre:/'mi:tә/n.公尺,格律,韵律[医]米,公尺in our knowledge of the position of the planets,任何不确定性哪怕只是几米之差can lead to radically different predictions.都可能产生截然不同的预测结果radically:/'rædikәli/adv.根本地,完全地prediction:/pri'dikʃәn/n.预言,预报[化]预测And that’s because the system itself,the orbits of the这是因为太阳系本身包括行星的公转轨道planets,are not stable over very long timescales.在漫长的宇宙时间里是不稳定的stable:/'steibl/CET6CET4TEM4TOF n.马房,牛棚a.稳定的,安定的,坚固的,坚定的vt.赶入马房vi.被关在马厩timescale:/ˈtaɪmskeɪl/时间表[尺度],时标,时间量程19 So planets don’t necessarily remain in the same orbits所以行星未必会始终保持在同一轨道上forever.necessarily:/'nesisәrili/adv.必然地,必须地,必要地remain:/ri'mein/CET6CET4vi.保持,逗留,剩余[法]停留,居住,继续And the evidence we’ve gathered水星表面探测到的evidence:/'evidәns/CET6CET4TEM4TOF n.根据,证据,迹象[经]证据,凭证gather:/'gæðә/n.集合,聚集vi.聚集,集合,渐增vt.使聚集,搜集,积聚from the volatiles on Mercury’s surface,大量挥发性元素volatile:/'vɒlәtail/GRE TEM8TOF a.挥发性的,可变的,不稳定的,飞行的,轻快的,爆炸性的n.有翅动物,挥发物[计]易失的surface:/'sә:ﬁs/n.面,表面,水面,外表,平面a.表面的,外观的,肤浅的,水面上的vt.使成平面,使浮出水面vi.浮出水面,呈现,在地面上工作and the unusual size of its core,以及超乎寻常的内核大小suggests that this may have been what happened.这些可能都在讲述着水星所经历过的故事If Mercury began its life如果水星真是在170million km further away from the sun...距离太阳1.7亿公里的地方孕育的km://[医]千米,公里..then it would have been in a region of space那它所在的空间区域region:/'ri:dʒәn/CET6CET4TEM4TOF n.区域,地带,地区,领域,范围,区[计]区,区域where the young Mars was also forming.很可能也是年轻火星的形成地This region was full of scores of planetary embryos,在这片空间区域内数十颗行星胚胎embryo:/'embriәu/TOF n.胚胎,胎儿,胚芽[医]胚,胚胎all fighting for position.你推我搡争夺最佳位置20S01E01Amongst the chaos,something large kicked Mercuryinwardsamongst:/ә'mʌŋst/CET4prep.在...当中,在...之间,在...之中chaos:/'keiɒs/GRE TOF n.大混乱,混沌[化]混沌;浑沌kicked:/kikt/v.踢(kick的过去式和过去分词);踢蹬,踢（腿）;（因干了蠢事、失去良机等）对（自己）生气;体育运动inwards:/'inwәdz/adv.在内部,向中心,向内,内里[经]进口税在一片混乱中某个大型天体将水星推向了towards the sun.towards:/tә'wɔ:dz/prep.向,对于,为了太阳的怀抱Mercury collided with another embryo.collide:/kә'laid/CET6TEM4TOF vi.碰撞,互撞,抵触水星与另一颗行星胚胎发生碰撞A glancing blow saw much of its crustglance:/'glɑ:ns/GRE CET6CET4TEM4n.一瞥,闪光,掠过,辉矿类vi.扫视,闪光,掠过,提到,略说vt.扫视,反射,使掠过crust:/krʌst/GRE CET4TEM4TOF n.外壳,坚硬外皮,面包皮vt.盖以硬皮vi.结硬皮伴随着斜掠而过的撞击水星的大部分地壳和地幔and mantle lost to space.mantle:/'mæntl/GRE TOF n.斗篷,罩子,披风vt.罩住,覆盖vi.覆盖,脸红散落进了茫茫太空Much of this material remained behind,material:/mә'tiәriәl/CET4TEM4TOF n.材料,物资,素材,布料,资料a.物质的,肉体的,重要的这些物质大都保留下来perhaps helping to form the early Venus.最终催生了早期的金星If this theory is correct,then Mercury,theory:/'θiәri/CET4TEM4n.理论,学说,原理,意见,推测[化]理论如果这一理论正确那现在的水星now little more than a planetary core,continued to-wards the sun不过是当初的内核它继续向着太阳运动21 and ended up in the peculiar elliptical orbit we see to-最终形成了现在这种奇特的椭圆形轨道day.peculiar:/pi'kju:ljә/CET6CET4TEM4TOF a.奇特的,罕见的,特殊的,特别的n.特有财产,特权elliptical:/i'liptikәl/GRE TEM8TOF a.椭圆的[医]椭圆形的The idea that Mercury’s outer layers were stripped水星在数十亿年前的剧烈撞击中awayouter:/'autә/CET4TEM4a.外部的,外面的,在外的,远离中心的[机]外部的,外面的,外侧的strip:/strip/GRE CET4TEM4TEM8TOF n.长条,条状,带,脱衣舞vt.脱衣,被剥去,剥夺,拆卸vi.脱衣服layer:/'leiә/CET6CET4TOF n.层,产卵鸡,放置者vt.分层堆积,压植[计]层in some violent collision many billions of years ago被剥离外层的理论从表面看来violent:/'vaiәlәnt/CET6CET4TOF a.暴力的,猛烈的,激烈的,极端的,凶暴的collision:/kә'liʒәn/GRE CET6CET4TEM4n.碰撞,冲突,抵触[计]冲突billion:/'biljәn/num.十亿,十亿个is a superficially attractive one,的确很有吸引力superﬁcially://adv.表面,表面性,浅层,不深,表皮,(贬)肤浅,一知半解,浅薄,平方,浮面attractive:/ә'træktiv/CET6CET4TEM4TOF a.吸引人的,有魅力的[法]有吸引力的,有迷惑力的but the theory does have problems.这个理论也存在几个问题Any collision violent enough to do that heats up the如果撞击足够力道都会造成水星升温planetheat:/hi:t/n.热,热度,体温,高潮vi.加热,激昂,加剧vt.把...加热,使激动and that boils away the volatiles.和挥发性元素逃逸boil:/bɒil/n.煮沸,沸腾,疖v.煮沸,激动So you have to think of a very specific kind of collision,所以我们必须设想一种特别的碰撞speciﬁc:/spi'siﬁk/CET6CET4TEM4n.特效药,特性a.特殊的,明确的,具有特效的,特定地,具体地。

物理专业英语词汇(I)题库

物理专业英语词汇(I)ice 冰ice calorimeter 冰量热计ice model 冰模型iconoscope 光电摄象管icosahedron 二十面体ideal black body 理想黑体ideal constraints 理想拘束ideal crystal 理想晶体ideal fluid 完整铃ideal gas 理想气体ideal gas law 理想气体定律ideal lattice 理想晶格ideal liquid 理想液体ideal solid 理想固体ideal solution 理想溶液ideally imperfect crystal 理想非完满晶体ideally perfect crystal 理想完满晶体identity parameter 晶体参数ignition 点火ignition potential 点火电位ignitron 点火管illuminance 光照度illuminant 光源illuminating engineering 照盲程学illuminating lamp照闷illumination 光照度illumination curve 照度曲线illumination photometer 照度计illumination photometry 照度丈量illuminator 照冒置illuminometer 照度计image 象image analyzer 图象剖析器image charge 象电荷image contrast 象对照度image converter 变象管image converter tube 变象管image distortion 图象失真image force 象力image formation 成象image frequency 象频image hologram 象全息图image iconoscope 图象光电摄象管image intensifier 影象加强器影象放大器image intensifier tube 影象加强器影象放大器image orthicon 超正析象管image parameter 成象参数image pickup tube 摄象管image plane 象平面image point 象点image processing 图象办理image ratio 镜频波道的相对增益image restoration 象恢复image space 象空间image surface 象曲面imagelyzer 图象剖析器immersion 淹没immersion lens 淹没透镜immersion method 淹无法immersion microscope 油浸显微镜immersion objective 淹没物镜immersion refractometer 淹没折射计impact 冲击impact ionization 碰撞电离impact matrix 碰撞矩阵impact parameter 碰撞参数impact parameter method 碰撞参数法impact strength 冲豢度impact stress 冲沪力impact test 冲辉验impedance 阻抗impedance bridge 阻抗电桥impedance matching 阻抗般配imperfect crystal 非完满晶体imperfect gas 非理想气体impressed forces 外力imprisonment of resonance radiation 共振辐射陷获improper variable 准变星impulse 冲击冲量impulse approximation 冲稽似impulse function 脉冲函数impulse generator 脉冲发生器impulse of force 冲量impulsive current 脉冲电流impulsive force 冲力impulsive sound 冲基impulsive tone 撞霍impurity 杂质impurity atom 杂质原子impurity band 杂质能带impurity center 杂质中心impurity conduction 杂质导电impurity level 杂质能级impurity scattering 杂质散射impurity semiconductor 杂质半导体in clockwise direction 向顺时针的方向in counter colckwise direction 向反时针的方向in situ observation 就地察看incandescence 白炽incandescent lamp 白炽灯inch 英寸incidence 入射incidence angle 入射角incident beam 入射束incident light 入射光incident particle 入射粒子incident plane 入射面incident ray 入射光芒incident wave 入射波inclination factor 倾斜因子inclinometer 磁倾计incoherence 非相关性incoherent light 非相关光incoherent scatteering 非相关散射incommensurate structure 不相应构造incompressibility 不行压缩性incompressible flow 不行压缩流indefinite metric 不定胸怀independent atom model 独立原子模型independent particle 独立粒子independent particle model 独立粒子模型independent variable 自变数indeterminancy 不确立性indeterminancy principle 测禁止原理index 指数index of refraction 折射率indicating lamp 指示灯indicator 指示器指示剂indifferent equilibrium 中性均衡indirect exchange interaction 间接交换互相酌indirect illumination 间接照明indirect measurement间接丈量indirect transition 间接跃迁indirectly heated cathode 旁热式阴极indistinguishability of identical particles 全同粒子的不行分辨性indium 铟individual error 人为偏差individual excitation 独自激发induced current 感觉电流induced electromotive force 感觉电动势induced emission 感觉发射induced radioactivity 感觉放射性induced representation 引诱表示inductance 电感感觉系数inductance coil 感觉线圈induction 感觉; 概括induction accelerator 感觉加快器induction coefficient 感觉系数induction coil感觉线圈induction field 感觉磁场induction furnace 感觉电炉induction heating 感觉加热induction method 概括法induction motor 感觉电动机inductive 感觉的inductor coil 感觉线圈indus 印第安座inelastic collision 非弹性碰撞inelastic scattering 非弹性散射inert gas 惰性气体inertia 惯性inertial force 惯性力inertial frame of reference 惯性系inertial mass 惯性质量inertial resistance 惯性阻力inertial system 惯性系inertial wave 惯性波inferior conjunction 下合inferior mirage 下现幻景inferior planet 地行家星infinite medium 无穷介质infinite universe 无穷宇宙infinitesimal rotation 无量小转动infinitesimal transformation 无量小变换inflationary universe 狂涨宇宙inflector 偏转器influence machine感觉起电机information processing 信息办理information quantity 信息量information retrieval 信息恢复information theory 信息论infra acoustic 声下的infra acoustic frequency 亚声频infra sound 次声infranics 红外线电子学infrared 红外线的infrared active 红外激活的infrared astronomical satellite 红外天文卫星infrared astronomy 红外天文学infrared catastrophe 红外灾变infrared divergence 红外发散infrared lamp 红外灯infrared laser 红外激光器infrared magnitude 红外星等infrared microscope 红外线显微镜infrared photocell 红外线光电管infrared photography 红外拍照infrared radiation 红外辐射infrared rays 红外线infrared spectrophotometer 红外分光光度计infrared spectroscopy 红外光谱学infrared spectrum 红外光谱inhomogeneous broadening 非平均增宽inhomogeneous plasma 非平均等离子体inhomogeneous superconductor 非均质超导体inhomogeneous universe 非平均宇宙initial black hole 原始黑洞initial permeability 初始磁导率initial phase 初相initial state 初态initial stress 初应力initial velocity 初速度injection 注入injection laser 注入型激光器注入型二极管激光器injector accelerator 注入加快器injury 损害inlet pressure 入口压力inner bremsstrahlung 内韧致辐射inner corona 内冕inner electron 内层电子inner product 内积inner quantum number 内量子数inner shell 内壳层input 输入input output channel 输入输出通道input output unit 输出输入装置input program 输入程序input routine 输入程序insolation 日射inspection 检查instability 不稳固性instability energy 不稳固能instantaneous axis of rotation 刹时转动轴instantaneous neutron 瞬发中子instantaneous pole 刹时极instantaneous power 刹时功率instanton 瞬子instruction 指令instrument 仪器仪表instrument transformer 仪表变换器instrumental error 仪企差instrumental function 仪漂数insulating paper绝缘纸insulating transformer 绝缘变压器insulation 绝缘insulation resistance 绝缘电阻insulator 绝缘体integral calculus 积分学integral equation 积分方程integral invariant 积分不变式integral transform 积分变换integrated circuit 集成电路integrated optics 集成光学integrated reflection intensity 积分反射强度integrating sphere 乌布利希球integrating wattmeter 积累瓦特计integration circuit 积分电路integration type analog to digital conversion 积分型模拟数字变换intense slow positron beam 强慢速阳电子束intensifier 加厚剂intensity 强度intensity alternation 强度交变intensity factors of spectral lines 谱线强度因子intensity modulation 亮度灯intensity of magnetic field 磁场强度intensity of magnetization 磁化强度intensity of radioactivity 放射性强度intensity of sound 声强intensity region 强度范围intensive quantity 内包量intensive variable 示强变量interaction 互相酌interaction energy 互相酌能interaction force 互相酌力interaction potential 互相酌势interaction range 互相酌区interatomic 原子间的interatomic distance 原子间距离interatomic forces 原子间力intercalation 夹层interchange instability 变换不稳固性interchangeability 交换性intercombination 互相组合intercrystalline 晶粒间的interdiffusion 互扩散interface 界限面interfacial electric phenomenon 界面电现象interfacial potential 界面势interfacial tension 界面张力interfacial viscosity 界面粘性interference 干预interference color 扰乱色interference filter 扰乱滤光片interference fringe 干预条纹interference microscope 干预显微镜interference of equal inclination 等倾角干预interference of equal thickness 等厚度干预interference of light 光的干预interference of polarized light 偏振光的干预interference refractometer 干预折射计interference spectroscope 干预分光镜interferometer 干预仪interferometry 干预胸怀学intergalactic matter 星系际物质intergalactic space 星系际空间intermediate coupling 中间耦合intermediate energy 中间能量intermediate energy physics 中能物理学intermediate frequency 中频intermediate frequency transformer 中频变换器intermediate image 中间影象intermediate neutron 中速中子intermediate nucleus 复核intermediate orbit 中间轨道intermediate state 中间态intermediate vector boson 弱玻色子intermetallic compounds 金属间化合物intermittent discharge 间歇放电intermolecular 分子间的intermolecular force 分子间力intermolecular interaction 分子间互相酌internal adsorption 内吸附internal conversion 内变换internal conversion electron 内变换电子internal electron pair creation 内电子对产生internal energy 内能internal exposure 内照耀internal force 内力internal friction 内摩擦internal impedance 内阻抗internal ionization 内电离internal magnetic field 内磁场internal photoelectric effect 内光电效应internal pressure 内压internal quantum number 内量子数internal reflection 内反射internal resistance 内阻internal rotation 内旋转internal storage 内部储存器internal stress 内应力internal target 内靶internal viscosity 内粘滞international atomic time 国际原子时international geophysical year 国际地球物理年international latitude service 国际纬度服务international practical temperature scale 国际适用温标international prototype metre 国际米原器international standard atomsphere 国际标准大气international system of units 国际单位制international temperature scale 国际温标international thermonuclear experimental reactor 国际热核实验反响堆international unit 国际单位interpenetration 互相穿透interplanar crystal spacing 晶面间距interplanetary dust 行星际灰尘interplanetary magnetic field 行星际磁场interplanetary matter 行星际物质interplanetary space 行星际空间interpolation formula 内插公式interrupt 中止interrupter 断续器interspace 缝隙interstellar absorption 星际汲取interstellar absorption line 星际线interstellar cloud 星际云interstellar dust 星际灰尘interstellar gas 星际气体interstellar line 星际线interstellar magnetic field 星际磁场interstellar matter 星际物质interstellar molecule 星际分子interstellar reddening 星际红化interstellar space 星际空间interstice 缝隙interstitial alloy 填隙式合金interstitial atom 填隙原子interstitial diffusion 填隙式扩散interstitial ion 填隙离子interstitial solid solution 填隙式固溶体interval间隔interval rule 间隔规则intraatomic 原子内的intracrystalline 晶体内的intramolecular分子内的intramolecular bond 分子内键intramolecular forces 分子内力intramolecular rotation 分子内转动intrinsic conduction 本占电intrinsic energy 内能intrinsic magnetic moment 固有磁矩intrinsic magnetization 内倥化intrinsic parity 内兕称intrinsic permeability 固有磁导率intrinsic semiconductor 本针导体intrinsic viscosity 本粘性intrinsic wavelength 固有波长invar 殷钢invariable plane 不变平面invariance 不变性invariant 不变式invariant of strain 应变不变量invariant subgroup 不变子群inverse circuit 反演电路inverse compton effect 逆康普顿效应inverse fluorite structure 逆萤石构造inverse photoelectric effect 逆光电效应inverse photoelectron spectroscopy 逆光电光谱学inverse piezoelectric effect 逆压电效应inverse predissociation 逆前级离解inverse problem 逆问题inverse process 逆过程inverse proportion 反比率inverse raman effect 反转喇曼效应inverse raman spectroscopy反转喇曼光谱学inverse reaction 逆反响inverse scattering method 逆散射法inverse spinel 反尖晶石inverse spinel structure 反尖晶石型构造inverse square law 平方反比律inverse transformation 逆变换inverse voltage 逆电压inverse zeeman effect 反向塞曼效应inversion 反演inversion axis 反演轴inversion doublet 反转两重线inversion formula 反演公式inversion layer 反转层 ; 逆温层inversion spectrum 反转光谱inversion system 倒象系inversion temperature 变换温度invert 反演inverted magnetron gage 逆磁控管计inverted multiplet 反转多重态inverted term颠倒项inverter 逆变换装置inviscid flow 无粘性流invisible radiation 不行见的辐射invisible rays 不行见的射线iodine 碘ion 离子ion accelerator 离子加快器ion acceptor 离子接受体ion acoustic instability 离子声波不稳固性ion activity 离子活度ion avalanche 离子雪崩ion beam 离子束ion beam probe 离子束探针ion bombardment 离子轰击ion channelling 离子沟道效应ion cloud 离子云ion cluster 离子簇ion concentration 离子浓度ion condensation 离子凝集ion cyclotron frequency 离子盘旋频次ion cyclotron resonance heating 离子盘旋共振加热ion cyclotron resonance method 离子盘旋共振法ion density 离子密度ion diffusion 离子扩散ion electron recombination 离子电子再化合ion exchange 离子交换ion exchange resin 离子交换尸ion impact 离子碰撞ion implantation 离子注入ion implanted junction 离子注入结ion induced desorption 离子感觉退吸ion induced x ray analysis 离子感觉 x 射线剖析ion lattice 离子晶格ion loss 离子消耗ion microprobe analyzer 离子微探针剖析器ion microscope 离子显微镜ion molecule 离子型分子ion neutralization 离子中和ion neutralization spectroscopy 离子中和波谱学ion optics 离子光学ion orbit 离子轨道ion pair 离子对ion pair formation 离子对生成ion plasma frequency 离子等离子体频次ion pump 离子泵ion recombination 离子复合ion saturation current 离子饱和电流ion scattering spectroscopy 离子散射能谱学ion selective electrode 离子选择电极ion sheath 离子鞘ion source 离子源ion temperature 离子温度ion trap 离子圈套ion yield 离子产额ionic atmosphere 离子氛围ionic bond 异极键ionic charge 离子电荷ionic compound 离子化合物ionic conduction 离子导电ionic crystal 离子晶体ionic current 离子电流ionic laser 离子激光器ionic migration 离子迁徙ionic mobility 离子迁徙率ionic molecule 离子型分子ionic polymerization 离子聚合ionic radius 离子半径ionic recombination 离子复合ionic strength 离子强度ionic structure 离子构造ionium 锾ionization 电离ionization by collision 碰撞电离ionization chamber 电离室ionization current 电离电流ionization density 电离密度ionization fluctuation 电离涨落ionization limit 电离极限ionization loss 电离损失ionization potential 电离电势ionization power 致电离能力ionization rate 电离率ionization vacuumgage 电离真空计ionized atom 电离原子ionized layer 电离层ionizer 电离装置ionizing energy 电离能量ionizing power 致电离能力ionizing radiation 电离线ionoluminescence 离子发光ionometer离子计ionosphere电离层ionospheric disturbance电离层扰动ionospheric storm 电离层暴iras object iras 天体iridescence 虹色iridium 铱iris 可变光栏iris diaphragm锁定光栏iris type accelerator guide 隔阂型加快波导管iron 铁iron constantan thermocouple 铁康铜热电偶iron group elements 铁族元素iron loss 铁耗irradiation 辐照irradiation damage 辐照损害irradiation hardening 辐照硬化irradiation reactor 辐照用堆irreducible representation 不行约表示irregular galaxy 不规则星系irregular nebula 不规则星云irregular reflection 不规则反射irregular variable 不规则变星irreversibility 不行逆性irreversible process 不行逆过程irreversible reaction 不行逆反响irrotational field 非旋场isentrope 等熵线isentropic analysis 等熵剖析isentropic surface 等熵面ising model 伊辛模型isoanomalous line 等异样线isobar 等压线isobaric 等压的isobaric analog resonance同质异位素相像共振isobaric analog state 同质异位素相像态isobaric process 等压过程isobaric surface 等压面isocandle diagram 等烛光图isochor 等容线isochromatic 等色的isochromatic line 等色线isochromatic surface 等色面isochrone 等时线isochronism 等时性isochronous cyclotron 等时性盘旋加快器isoclinal 等倾线isoclinal line 等倾线isoclinic line 等倾线isodiaphere 同差素isodynamic line 等力线isoelectric point 等电点isogon 等偏线isolated point 孤点isolation 隔绝isolator 隔绝器绝缘体isolux curve 等照度线isomagnetism 等偏isomer 同质异能素isomer shift 同质异能位移isomeric state 同质异能态isomeric transition 同质异能跃迁isomerism 同质异能性isomerization energy 同质异能化能isometric process 等容过程isomorphism 同构isopycnic 等密度的isopycnic line 等密度线isospace 电荷空间isospin 同位旋isostasy 地壳均衡说isostere 等比容线isosteric molecule 电子等排分子isotherm 等温线isothermal 等温的isothermal atmosphere 等温大气isothermal change 等温变化isothermal equilibrium 等温均衡isothermal expansion 等温膨胀isothermal process 等温过程isotone 同中子素isotope 同位素isotope analysis 同位素剖析isotope effect 同位素效应isotope incoherence 同位素非相关性isotope separation 同位素分别isotope separator 同位素分别器isotope shift 同位素位移isotopic abundance 同位素丰度isotopic dating 同位素测年纪isotopic invariance 同位旋不变性isotopic spin同位旋isotopic tracer 示踪同位素isotropic scattering 蛤同性散射isotropic turbulence 蛤同性湍流isotropic universe 蛤同性宇宙isotropy 蛤同性iterative method 迭代法itinerant electron 巡回电子itinerant electron magnetism 遍历电子磁性。

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arXiv:astro-ph/0309052v1 2 Sep 2003TypeIaSupernovaeinsemi-detachedbinarysystemsA.V.Fedorova,A.V.Tutukov,L.R.YungelsonInstituteofAstronomyofRASPyatnitskaya48,Moscow119017,Russia

afed@inasan.rssi.ru,atutukov@inasan.rssi.ru,lry@inasan.rssi.ru

Abstract.Wehaveconsideredscenariosfortheevolutionofclosebinariesresult-ingintheformationofsemi-detachedsystemsinwhichawhitedwarfcanaccumulateChandrasekharmassbyaccretionfromamain-sequenceorsubgiantcompanionwithM∼2M⊙.Thesewhitedwarfs,probably,explodeastypeIasupernovaeorcollapsewithformationofneutronstars.WehavecarriedoutapopulationsynthesisstudyforthesesystemsandhaveestimatedtheoccurrencerateofsucheventsintheGalaxy,dependingontheparameterofcommonenvelopes,mass-exchangerateinthebinary,reactionofthemain-sequencecomponentonaccretionofheliumintheinterveningphaseofevolution.WehavefoundthatthemodeloccurrencerateofSNeIainsemi-detachedsystemsis≃0.2×10−3yr−1,i.e.,itdoesnotexceed∼10%oftheobservationalestimateoftheGalacticoccurrencerateofSNeIa.

1IntroductionTheproblemofprogenitorsoftypeIaSupernovae(SNeIa)isnotsolvedasyet.Rel-ativelyhighfractionofso-calledpeculiarSNeIa[possibly,upto≃40%,Lietal.(2001)]maysuggestthattheprogenitorsofSNeIamayformanon-homogeneousgroup.Usu-ally,threepossibilitiesareconsidered:(i)explosionofawhitedwarfthathasaccumu-latedChandrasekharmassMChbyaccretioninasemi-detached(Whelan&Iben,1973;Iben&Tutukov,1984)ordetached(Tutukov&Yungelson,1976;Munari&Renzini,1992)binarysystem;(ii)explosionofamergerproductofapairofwhitedwarfswith(super)Chandrasekhartotalmass(Tutukov&Yungelson,1981;Webbink,1984;Iben&Tutukov,1984);(iii)explosionofa(sub)Chandrasekharmasswhitedwarfini-tiatedbythedetonationofheliuminthelayerofaccretedmatterinasemi-detachedsystemwithheliumdonor[edge-litdetonation,Livne(1990)].InthepresentpaperweapplypopulationsynthesisforclosebinarystarsfortheestimationofpossibleoccurrencerateofSNeIaandaccretioninducedcollapses(AIC)duetoaccumulationofChandrasekharmassbywhitedwarfsinsemi-detachedsystemswithhydrogen-heliumdonors.WeperformadetailedanalysisofthedependenceofresultsontheparametersofcalculationsandshowthatintheGalaxy<∼10%ofallSNIamayoccurinthesesystems.

2ScenariosofevolutiontoSNIaScenariosofevolutionofclosebinariestoSNIaaresketched(outofscale)inFigs.1and2(hereafter,scenariosIandII,respectively).Inbothscenariosinitialmassofthe

1primarycomponentisM10≈5−11M⊙,massofthesecondaryisM20≈0.8−3.5M⊙.InscenarioIseparationofcomponentscorrespondstotheRLOFbytheprimaryinthehydrogen-shellburningstage(caseBofmassexchange).Masslossbytheprimaryresultsinformationofacommonenvelope.Evolutioninsidecommonenvelopeleadstotheshrinkageoftheorbit.Duetothemassloss,primarycomponentbecomesaheliumstarwithamass≃(0.8−2.5)M⊙.HeliumstarsofthismassrangeexpandafterformationoftheCO-core(Iben&Tutukov,1985;Bitzarakietal.,2002).ThisresultsinthesecondRLOFandaccretionofhelium-enrichedmatterbythecompanion.MasslossbyanexpandingstarwithaCO-coreandaheliumenvelopeoccursinthethermaltimescaleofthestar(∼105yr).ApplyingresultsofevolutionarycomputationsbyIben&Tutukov(1985)onemayestimatethemassofthelostenvelope

∆M7M⊙

󰀅4

(1)

andmass-lossrate˙MHe≈6.3×10−13

󰀃M103Accretionofheliumbyamain-sequencestarwithinitialmassof2M⊙

Thepossibilityofaccretionofhelium,i.e.,ofthematterwithmolecularweightµexceedingthatatthesurfaceofthemain-sequenceaccretor,wasnoticedlongago(Stothers&Simon,1969).However,evolutionoflow-andmoderate-massstarsaccret-ingHewasnotstudiedasyet.Wehaveconsideredtheevolutionofamain-sequencestarwithinitialmassM0=2M⊙thataccretes∆M=0.5M⊙ofhelium-richmatterwithaconstantrate˙Ma.ThiscombinationofM0and∆Mcorrespondstoaquitetypicalclosebinarysystemwithinitialmassofcomponents9and2M⊙thatmaybeaprogenitorofaSNIa[seeEq.(1)andFig.5below].Computationswerecarriedoutforseveralvaluesof˙Ma(Table1).Thechoiceforthesetof˙MawasdeﬁnedbythepossibilityofrealizationoftheseratesintheevolutionaryscenariosresultinginSNIa[seeEq.(2)andFig.5].Weusedforthecomputationstheevolutionarycodedesignedforthestudiesoflow-massstars(Tutukov&Fedorova,2001).InitialchemicalcompositionofaccretorwasX=0.70,Y=0.28,Z=0.02,thechemicalcompositionofaccretedmatter–Y=0.98,Z=0.02.Wehaveconsideredtwosetsofassumptionsontheevolutionofaccretingstar.Aninversegradientofmolecularweighthastoleadtotheinstabilityandmixingattheborderofheliumlayer(see,e.g.,Ulrich,1972).Kippenhahnetal.(1980)haveshownthatforanon-rotatingspherically-symmetricstarthemixingmaybeconsideredasformationofhelium“bubbles”andtheirdiﬀusioninsidehydrogen-richsubstratum.Sinkingbubblesaregraduallydestroyedandmixedwithsurroundingmatter.Inthismodel,diﬀusioncoeﬃcientDis