悬赏翻译几段维基词条【400MFB】

维基百科暗物质词条中的几个部分，地址：
http://en.wikipedia.org/wiki/Dark_matter

包括：
2.1 Galactic rotation curves
2.3 Galaxy clusters and gravitational lensing
2.4 Cosmic microwave background
2.8 Structure formation


以上每部分100MFB，其中2.8如能翻译进一步的内容：http://en.wikipedia.org/wiki/Structure_formation，则单独奖励500MFB。
所有MFB将通过个人论坛转账发出。


此为暗物质一帖未完成的部分，因为近日时间有限，且对这几部分内容不太熟悉，特求助各位。

1.星系螺旋臂
2.星系簇与重力透镜（效应）
3.宇宙微波背景（辐射）
4.结构构成（形式）

LS，是翻译整个部分，不是那几个。另外，注意翻译的准确，第一个应该是星系旋转曲线。

回复 2# 周星驰

楼主显然是在招人翻译这些词条的内容.

另外这些名词应该是:

1. 星系的旋转曲线
2. 星系团与引力透镜
3. 宇宙微波背景辐射
4. 结构形成

看这个能不能捞点小钱,哈哈

structure formation

结构形成

Main article: structure formation
主条目:结构形成


Dark matter is crucial to the Big Bang model of cosmology as a component which corresponds directly to measurements of the parameters associated with Friedmann cosmology solutions to general relativity. In particular, measurements of the cosmic microwave background anisotropies correspond to a cosmology where much of the matter interacts with photons more weakly than the known forces that couple light interactions to baryonic matter. Likewise, a significant amount of non-baryonic, cold matter is necessary to explain the large-scale structure of the universe.

暗物质是大爆炸宇宙学模型的一个关键组分,其跟广义相对论的弗里德曼宇宙学解(Friedmann cosmology solution)中的参数测量直接相关.特别是.在通过宇宙微波背景的各向异性测到的宇宙学中,许多物质跟光子的相互作用比已知的光子跟重子相互作用的力要弱得多.因此,为了解释宇宙的大尺度结构,就需要有一种相当数量的冷的物质.



Observations suggest that structure formation in the universe proceeds hierarchically, with the smallest structures collapsing first and followed by galaxies and then clusters of galaxies. As the structures collapse in the evolving universe, they begin to "light up" as the baryonic matter heats up through gravitational contraction and the object approaches hydrostatic pressure balance. Ordinary baryonic matter had too high a temperature, and too much pressure left over from the Big Bang to collapse and form smaller structures, such as stars, via the Jeans instability. Dark matter acts as a compactor of structure. This model not only corresponds with statistical surveying of the visible structure in the universe but also corresponds precisely to the dark matter predictions of the cosmic microwave background. However, in detail, some issues remain yet to be addressed including an absence of satellite galaxies from simulations and cores of dark matter halos which appear smoother than predicted.
观测表明宇宙中的结构形成呈等级进行,最小的结构最先坍缩,接着是星系再接着是星系团.随着宇宙的演化及结构的坍缩,重子通过引力收缩加热并被”点燃”,这些天体接近流体静力学平衡.普通的重子物质在大爆炸之后温度太高并且压强太大以致无法通过金斯不稳定性(Jeans instability)坍缩成小的结构,如恒星.对结构形成来说,暗物质就扮演着一个夯土机的角色.这个模型不仅跟宇宙中的可见结构的统计性质一致,而且与宇宙微波背景预言的暗物质精确相符.然而,一些细节仍然需要再研究,比如跟数值模型相比卫星星系的缺失,以及暗物质晕中心的核似乎比预言的要平.

This bottom up model of structure formation requires something like cold dark matter to succeed. Large computer simulations of billions of dark matter particles have been used[41] to confirm that the cold dark matter model of structure formation is consistent with the structures observed in the universe through galaxy surveys, such as the Sloan Digital Sky Survey and 2dF Galaxy Redshift Survey, as well as observations of the Lyman-alpha forest. These studies have been crucial in constructing the Lambda-CDM model which measures the cosmological parameters, including the fraction of the universe made up of baryons and dark matter.
这个自下而上的结构性成模型需要冷暗物质才行.有数十亿暗物质粒子的大规模数值模拟证实,冷暗物质模型的机构形成跟通过星系巡天观测到的宇宙中的结构一致.这些巡天包括斯隆数字巡天(Sloan Digital Sky Survey), 2dF星系红移巡天(2dF Galaxy Redshift Survey)以及赖曼阿尔法森林(Lyman-alpha forest)的观测.这些研究在构建Lambda-CDM模型过程中非常关键.该模型测量了宇宙学参数,包括构成宇宙的重子跟暗物质的比例.


3D map of the large-scale distribution of dark matter, reconstructed from measurements of weak gravitational lensing with the Hubble Space Telescope.
暗物质大尺度分布的3维图,通过哈勃空间望远镜的引力透镜测量重构.

星系团和引力透镜我来翻译吧
http://www.astronomy.com.cn/bbs/thread-143505-1-1.html

觉得voyagerbb的翻译很好，水平很高。  
只是个别地方不如positron来得精准。
vanlog 发表于 2010-8-18 13:16

                               
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何意？

试着翻译一下旋转曲线吧。


Galactic rotation curves

星系旋转曲线

For 40 years after Zwicky's initial observations, no other corroborating observations
indicated that the mass to light ratio was anything other than unity. Then, in the late
1960s and early 1970s, Vera Rubin, a young astronomer at the Department of Terrestrial
Magnetism at the Carnegie Institution of Washington presented findings based on a new
sensitive spectrograph that could measure the velocity curve of edge-on spiral galaxies to
a greater degree of accuracy than had ever before been achieved.[8] Together with fellow
staff-member Kent Ford, Rubin announced at a 1975 meeting of the American Astronomical
Society the discovery that most stars in spiral galaxies orbit at roughly the same speed,
which implied that their mass densities were uniform well beyond the locations with most
of the stars (the galactic bulge). An influential paper presented these results in 1980.
[9] These results suggest that either Newtonian gravity does not apply universally or
that, conservatively, upwards of 50% of the mass of galaxies was contained in the
relatively dark galactic halo. Met with skepticism, Rubin insisted that the observations
were correct. Eventually other astronomers began to corroborate her work and it soon
became well-established that most galaxies were in fact dominated by "dark matter":

在茨威基最初的观测之后四十余年里都没有确切的证据表明(天体的)质光比不是一而是别的数值。然而
，到六十年代末至七十年代初期，华盛顿卡内基研究所地磁研究部门的年轻天文学家维拉.鲁宾对此做
出了新的发现。鲁宾的研究利用一种新的高度灵敏的摄谱仪，从而可以将侧向旋涡星系的速度曲线测量
测量到前所未有的精度。鲁宾和其同事肯特.福德于1975年在美国天文学会会议上宣布他们的一项发现
，即旋涡星系中大部分恒星绕星系的轨道速度都大致相同，这意味着这些星系的质量密度在远远超出大
量恒星所聚集的区域(星系核球)之外仍然保持均匀分布。1980年时他们发表了一篇很有影响的文章，介
绍了这些结果。这些结果表明，要么牛顿引力并不是普适地成立，要么星系质量的至少50%是包含在相
对较暗的星系晕中。面对着一些怀疑论者鲁宾坚持认为其观测是正确的。最终其他天文学家逐渐证实她
的结论，并且很快大家就建立起一个共识，即大多数星系事实上是由“暗物质”主导的：

Low Surface Brightness (LSB) galaxies.[10] LSBs are probably everywhere dark matter-
dominated, with the observed stellar populations making only a small contribution to
rotation curves. Such a property is extremely important because it allows one to avoid the
difficulties associated with the deprojection and disentanglement of the dark and visible
contributions to the rotation curves.[5]

低表面亮度星系(LSB)。LSBs可能是几乎完全由暗物质主导，其观测到的恒星对旋转曲线的贡献微乎其
微。这个性质非常重要，它使得我们可以避开解耦暗物质和可见物质对旋转曲线的分别贡献所面临的困
难。

Spiral Galaxies.[11] Rotation curves of both low and high surface luminosity galaxies
appear to suggest a universal density profile, which can be expressed as the sum of an
exponential thin stellar disk, and a spherical dark matter halo with a flat core of radius
r0 and density rho0=4.5e-2(r0/kpc)^(-2/3)M_sun pc^-3 (here, M_sun denotes a solar mass,
2e30 kg).

旋涡星系。不论是低还是高表面亮度的星系的旋转曲线似乎都意味着一个普适的密度轮廓，即可以表示
为一个指数薄盘和一个球状暗物质晕的叠加，其中暗晕具有一个半径为r0, 密度为rho0=4.5e-2
(r0/kpc)^(-2/3)M_sun pc^-3 (M_sun=2e30kg为太阳质量) 的核。

Elliptical galaxies. Some elliptical galaxies show evidence for dark matter via strong
gravitational lensing,[12] X-ray evidence reveals the presence of extended atmospheres of
hot gas that fill the dark haloes of isolated ellipticals and whose hydrostatic support
provides evidence for dark matter. Other ellipticals have low velocities in their
outskirts (tracked for example by planetary nebulae) and were interpreted as not having
dark matter haloes.[5] However simulations of disk-galaxy mergers indicate that stars were
torn by tidal forces from their original galaxies during the first close passage and put
on outgoing trajectories, explaining the low velocities even with a DM halo.[13] More
research is needed to clarify this situation.

椭圆星系。一些椭圆星系的强引力透镜效应给出暗物质存在的证据，其X射线辐射表明在孤立椭球的暗
晕中存在延展的热气体，这些热气体的流体静力学支撑表明有暗物质存在。另有一些的外围速度(例如
可以通过行星状星云的轨迹测量)较低椭圆星系则不需要暗物质晕就可以解释。然而，关于盘状星系并
合的模拟表明，在两个星系第一次密近接触时恒星将受到其原初星系的潮汐力拉扯从而被转移到外围轨
道上来，这可以在即便存在暗物质晕的情况下解释外围的低速度。我们还需要更多的研究以澄清这个问
题。

Note that simulated DM haloes have significantly steeper density profiles (having central
cusps) than are inferred from observations, which is a problem for cosmological models
with dark matter at the smallest scale of galaxies as of 2008.[5] This may only be a
problem of resolution: star-forming regions which might alter the dark matter distribution
via outflows of gas have been too small to resolve and model simultaneously with larger
dark matter clumps. A recent simulation[14] of a dwarf galaxy resolving these star-forming
regions reported that strong outflows from supernovae remove low-angular-momentum gas,
which inhibits the formation of a galactic bulge and decreases the dark matter density to
less than half of what it would have been in the central kiloparsec. These simulation
predictions - bulgeless and with shallow central dark matter profiles - correspond closely
to observations of actual dwarf galaxies. There are no such discrepancies at the larger
scales of clusters of galaxies and above, or in the outer regions of haloes of galaxies.

需要注意的是，模拟的暗物质晕的密度分布显著地比通过观测反演的陡(存在中心尖状分布)，这直到
2008年都是包含暗物质的宇宙学模型在星系最小尺度上存在的一个问题。这可能仅仅是分辨率的问题：
即可能会通过气体外流改变暗物质分布的恒星形成区相比较巨大的暗物质团块来说太小而难以在模拟暗
物质结构时加以分辨和建立模型处理。最近的一个关于矮星系的模拟分辨出了其恒星形成区，其结果表
明来自于超新星的强大外流吹走了低角动量气体，从而抑制了星系核球的形成，并且将中心kpc范围内
的暗物质密度降低为原来值的一半以下。这些数值模拟预言的无核结果以及更加平缓的暗物质中心密度
分布和实际矮星系的观测非常接近。在星系团以及更大尺度的结构中，或者是星系晕的外围区域不存在
上述矛盾。

Exceptions to this general picture of DM haloes for galaxies appear to be galaxies with
mass-to-light ratios close to that of stars. Subsequent to this, numerous observations
have been made that do indicate the presence of dark matter in various parts of the
cosmos. Together with Rubin's findings for spiral galaxies and Zwicky's work on galaxy
clusters, the observational evidence for dark matter has been collecting over the decades
to the point that today most astrophysicists accept its existence. As a unifying concept,
dark matter is one of the dominant features considered in the analysis of structures on
the order of galactic scale and larger.

关于该星系的暗物质晕的一般图像也有一些例外，存在于那些质光比接近恒星的星系中。然而已有大量
的观测的确表明在宇宙的各处都普遍存在暗物质。算上鲁宾关于旋涡星系的发现和茨威基对星系团的研
究，暗物质的观测证据在过去数十年间一直积累，时至今日大多数天体物理学家已接受其存在的事实。
作为一个统一的概念，暗物质在分析星系以及更大尺度的结构时已经作为要考虑的主要属性之一。

还需努力啊~

谢谢共享，正好需要

什么时候汉语能成为通用语言呢！

还有那些内容没翻译？我可以试试。

Cosmic microwave background
宇宙微波背景

The discovery and confirmation of the cosmic microwave background (CMB) radiation occurred in 1964.[33] Since then, many further measurements of the CMB have also supported and constrained this theory, perhaps the most famous being the NASA Cosmic Background Explorer (COBE). COBE found a residual temperature of 2.726 K and in 1992 detected for the first time the fluctuations (anisotropies) in the CMB, at a level of about one part in 105.[34] During the following decade, CMB anisotropies were further investigated by a large number of ground-based and balloon experiments. The primary goal of these experiments was to measure the angular scale of the first acoustic peak of the power spectrum of the anisotropies, for which COBE did not have sufficient resolution. In 2000–2001, several experiments, most notably BOOMERanG[35] found the Universe to be almost spatially flat by measuring the typical angular size (the size on the sky) of the anisotropies. During the 1990s, the first peak was measured with increasing sensitivity and by 2000 the BOOMERanG experiment reported that the highest power fluctuations occur at scales of approximately one degree. These measurements were able to rule out cosmic strings as the leading theory of cosmic structure formation, and suggested cosmic inflation was the right theory.
1964年，科学家发现并证实了宇宙微波背景（cosmic microwave background，CMB）辐射。自那以后，许多更进一步的宇宙微波背景测量方法，支持、修正（constrain）了这一理论。其中，最著名的可能要数 NASA 的宇宙背景探测器（Cosmic Background Explorer，COBE）了。它找到了 2.726 开的残留温度，并在 1992 年首次发现宇宙微波背景有十万分之一的起伏。之后 10 年，科学家或在地面、或利用气球，进行了大量的宇宙微波背景实验。这些实验的首要目标是，测定各向异性的功率谱中，主峰（the first acoustic peak）的大小（the angular scale）。因为，COBE 的分辨率不足以完成此项任务。在 2000 至 2001 年间的一些实验中，最值得注意的是“毫米波段气球观天计划（Balloon Observations of Millimetric Extragalactic Radiation and Geophysics telescope，BOOMERanG）”【译注1】。通过测量典型的各向异性的角尺度（一种测量太空的尺度），发现宇宙很可能是平坦的。在整个 1990 年代，科学家用灵敏度越来越高的设备去测量主峰。直到 2000 年的 BOOMERanG，才取得有价值的成果。这次实验表明，最高能量的波动范围，大概在一度之内。这些测量结果足以否定宇宙弦理论作为解释形成宇宙结构的领导地位，并且支持了宇宙膨胀的理论。

【译注1】毫米波段气球观天计划
http://zh.wikipedia.org/wiki/%E6 ... 9%E8%A8%88%E7%95%AB



A number of ground-based interferometers provided measurements of the fluctuations with higher accuracy over the next three years, including the Very Small Array, Degree Angular Scale Interferometer (DASI) and the Cosmic Background Imager (CBI). DASI made the first detection of the polarization of the CMB[36] [37] and the CBI provided the first E-mode polarization spectrum with compelling evidence that it is out of phase with the T-mode spectrum.[38] COBE's successor, the Wilkinson Microwave Anisotropy Probe (WMAP) has provided the most detailed measurements of (large-scale)anisotropies in the CMB as of 2009.[39] WMAP's measurements played the key role in establishing the current Standard Model of Cosmology, namely the Lambda-CDM model, a flat universe dominated by dark energy, supplemented by dark matter and atoms with density fluctuations seeded by a Gaussian, adiabatic, nearly scale invariant process. The basic properties of this universe are determined by five numbers: the density of matter, the density of atoms, the age of the universe (or equivalently, the Hubble constant today), the amplitude of the initial fluctuations, and their scale dependence. This model also requires a period of cosmic inflation. The WMAP data in fact ruled out several more complex cosmic inflation models, though supporting the one in Lambda-CDM amongst others.
在接下来的三年里，大量布置在地面的干涉仪肩负着用更高精度测量背景起伏的任务。这些干涉仪包括了甚小天线阵（the Very Small Array，VSA）、度角规干涉仪（Degree Angular Scale Interferometer，DASI）、宇宙背景成像仪（the Cosmic Background Imager，CBI）。DASI 首次实现了对南极上空的宇宙微波背景进行探测，CBI 也首次探测南极上空的 E 模式偏振谱（超过 T 模式偏振的相位），并获取了令人信服的数据。威尔金森微波各向异性探测器（the Wilkinson Microwave Anisotropy Probe，WMAP）是 COBE 的继任者，它已获取了迄今为止（截止 2009 年）最详细的（大尺度）各向异性观测数据。WMAP 的观测数据在建立λ- CDM 模型过程中，发挥了关键性的作用。λ- CDM（λ- Cold Dark Matter Model，λ- 冷暗物质模型【译注2】）是当今宇宙学的标准模型。该模型认为，我们所处的宇宙是一个以暗能量为主、加上暗物质和原子（即普通物质）构成的平坦（指空间曲率为零）宇宙。宇宙的基本属性取决于 5 个参数：物质密度、原子密度、宇宙年龄（等价于哈勃常数的现代值【译注3】）、初始波动振幅，以及这些参数对应的规模尺度。λ- CDM 模型也认为，宇宙曾有一段暴胀时间。实际上，WMAP 的观测数据否定了数个更为复杂的宇宙暴胀模型。相较而言，λ- CDM 模型则更符合 WMAP 的观测数据。

【译注2】λ- CDM 模型
http://zh.wikipedia.org/zh-cn/%CE%9BCDM%E6%A8%A1%E5%9E%8B

【译注3】哈勃常数（哈柏常数）
http://zh.wikipedia.org/wiki/%E5%93%88%E5%8B%83%E5%B8%B8%E6%95%B0#.E7.94.B1.E5.93.88.E6.9F.8F.E5.B8.B8.E6.95.B8.E5.B0.8E.E5.87.BA.E7.9A.84.E5.96.AE.E4.BD.8D

                               
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In summary, a successful Big Bang cosmology theory must fit with all available astronomical observations (known as the concordance model), in particular the CMB. In cosmology the CMB is explained as relic radiation from the big bang, originally at thousands of degrees kelvin but red shifted down to microwave by the expansion of the universe over the last thirteen billion years. The anisotropies in the CMB are explained as acoustic oscillations in the photon-baryon plasma (prior to the emission of the CMB after the photons decouple from the baryons at 379,000 years after the Big Bang) whose restoring force is gravity.[40] Ordinary (baryonic) matter interacts strongly with radiation whereas, by definition, dark matter does not—though both affect the oscillations by their gravity—so the two forms of matter will have different effects. The power spectrum of the CMB anisotropies shows a large main peak and smaller successive peaks, resolved down to the third peak as of 2009.e.g..[39] The main peak tells you most about the density of baryonic matter and the third peak most about the density of dark matter (see Cosmic microwave background radiation#Primary anisotropy).
总之，一个成功的宇宙大爆炸理论必须能够解释（fit）所有有效的太空观测数据（这称之为一致性模型），尤其是在宇宙微波背景方面。在宇宙学中，宇宙微波背景被认为是大爆炸残留的辐射。起初（指大爆炸之后），温度有数千开，随着宇宙在过去 130 亿年的持续膨胀，红移使得光衰变成微波。由光子和重子组成的等离子体内，存在着声波振荡【译注4】，造成了宇宙微波背景中的各向异性。普通物质（即重子构成的物质）通过辐射剧烈互动。按定义，暗物质虽然不会参与辐射互动，但暗物质与普通物质都可通过引力影响到等离子体内的声波振荡。当然，两种不同的物质形式会有不同的影响效果。宇宙微波背景辐射各向异性的功率谱显示，一个大的主峰后跟着若干个较小的能量峰。主峰主要表明了重子物质的密度，第三个峰则主要表明了暗物质的密度。

【译注4】等离子体
http://zh.wikipedia.org/wiki/%E7%AD%89%E7%A6%BB%E5%AD%90%E4%BD%93
注意这句话：“严格来说，等离子体是具有高位能动能的气体团”。

我是新人，偶然看到这帖子，希望能赶得上楼主的要求。

另外，我想问个问题：为什么标题“Cosmic microwave background宇宙微波背景”不能把中文放到下一行呢？我都试了好多遍了，每次编辑得好好的，但一提交，它就会跑上去第一行。。。

refla 发表于 2012-1-15 17:47

                               
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我是新人，偶然看到这帖子，希望能赶得上楼主的要求。

另外，我想问个问题：为什么标题“Cosmic microwave ...

你使用源代码编辑方式试试。就是右上角的那个“纯文本”选项。

总算排好了