查询词典 quasars

Grand Unified Theory, Lepton Stars and gamma-ray Bursts, Quasars

大统一理论，轻子星和γ射线暴，类星体

When Wyithe and Loeb combined both factors, they found that gravitational lensing might boost the apparent light output of 10% to 30% of the most distant quasars by a factor of 10 or more.

当Wyithe和Loeb把这两个因素合起来考虑的时候，他们发现引力透镜效应会由于受10个或更多的因素影响，明显地把大多数遥远类星体的亮度增强10%至30%。

Bao. I think he does not know the : quasar physics at all!: A simple reason: astronomers detected redshifts of quasars based on the spectr : al lines emitted from the emission line regions, which are 0.1 to 1 parsec (1p : arsec=3.26 light years) far away from the central black hole. Therefore there : is very little effect from the gravitational redshift!

观察到的类星体的光可在几日内有明显的变化，可见类星体的发光区大小在光日尺度以下，即使你认为类星体的光谱线产生于吸积盘，那么吸积盘的大小须在光日尺度以下才能不相矛盾，请你说出一个你认定的类星体吸积盘的大小尺度与该尺度内所具有的质量，及因此计算出的可忽略的引力红移。

The farthest quasars have popped up during the Sloan Digital Sky Survey, a multiyear effort to map the sky in exhaustive detail.

在"斯隆数字巡天"这个需要花费多年时间穷尽全天所有天体的巡天计划当中已经发现了最遥远的类星体。

The Chandra X-ray image shows hot gas in the galaxy and point sources that are a mixture of objects within the Sombrero as well as quasars in the background.

钱德拉拍摄的 X 射线图象显示的是星系中的热气体和点源，后者既有草帽星系内的不同天体，也有背景类星体。

This is not the dominant route for star formation in the nearby universe where galaxies are mature and quasars are virtually non-existent he says.

他说，这在左近的宇宙中不是恒星形成的次要途径，左近宇宙中的星系是成熟的，类星体实际上是不存在的。

This is not the dominant route for star formation in the nearby universe, where galaxies are mature and quasars are virtually non-existent, he says.

他说，这在附近的宇宙中不是恒星形成的主要途径，附近宇宙中的星系是成熟的，类星体实际上是不存在的。

The theory of accretion disks are important for many astrophysical phenomena, including Quasars, active galatic nucleic, X-ray binary stars, and young stellar objects. The most important branch of accretion djsk theory is the stability properties of djsks. It is widely considered that the luminosity variations of various astronomical objects are associated with the instability of accretion disk. The viscosity plays an important role in the accretion disk theory, and magnetic field exists commonly in astronomical phenomena. A more realistic analysis of the stabihty of the accretion disk should include both the radjal and azimuthal perturbations because of the strong shear of viscous flow.In this paper, according to the luminosity Variations of Various astronomical objects, we study the radial-azimuthal instability of an isothermal with magnetic field. We find that the radial and azimuthal fields B〓,B〓 are mainly responsible for enhancing the instability of the magneto-acoustic modes and non-axisymmetric modes,and that pulsational oscillations are larger in the radial than in the Z direction. The model may be useful in explaining the periodic light variation of FU orionis and. T Tauri stars.

在许多天体物理现象中，例如活动星系核，X-射线双星和年青的恒星理论中，吸积盘理论起着重要的作用，而吸积盘理论中的一个重要分支是吸积盘的不稳定性理论，普遍认为活动天体的周期，准周期光变现象与吸积盘的不稳定性有关，在吸积盘理论中，粘滞起着重要的作用，而磁场是天体物理中普遍存在的现象，对于几何薄吸积盘不稳定性分析，由于强剪切流的缘故，应该包括径向和环向扰动两个方面，本文结合天体物理中的各种周期，准周期光变现象，研究了含磁场的等温薄吸积盘的径向-环向振荡不稳定性，结果表明：磁场的径向和环向分量对磁声模和非轴对称模的不稳定性的增加起着主要的作用，且径向振荡大于轴向振荡，所得结果有利于解释FU Orionis和T Tauri Stars的周期光变现象。

Narrow Line Seyfert 1s (NLS1s, including high luminosity quasars with similar properties) are very important extrema of type Ⅰ AGNs. The unusualness of NLS1s is very useful to test the viabilities of AGNs models and thus provide a new way probing into AGN phenomena. The ratio of Fe to α-element (e. g., O, Ne, Mg...), Fe/α, can serve as an excellent indicator for constraining the ages of star-forming systems.

中文题名窄线SeyfertⅠ星系与活动星系核光学FeⅡ发射线副题名外文题名论文作者周宏岩导师周又元王挺贵学科专业天体物理研究领域\研究方向学位级别博士学位授予单位中国科学技术大学学位授予日期2003 论文页码总数127页关键词活动星系核河外星系馆藏号BSLW /2003 /P15 /7 窄线SeyfertⅠ型星系(Narrow Line Seyfert 1，NLS1，包括具有类似性质的类星体)是具有极端性质非常重要的一类Ⅰ型AGN，对NLS1的深入研究是限制和完善活动星系核理论模型的一条新途径。

The findings provide "powerful insights into how quasars form and evolve," says astronomer Amy Barger of the University of Wisconsin, Madison.

威斯康星大学麦迪逊分校的天文学家艾米·巴杰说，这些发现在类星体的形成和演化方面提供了深刻的认识。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了