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2021年09月08日:仙女大星系方向的深空影像-(The Deep Sky Toward Andromeda)
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2017年11月29日:M42:猎户座大星云-(M42: The Great Orion Nebula)
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2023-12-31
2023年12月31日:揭示计画的宇宙模拟影片-(Illustris: A Simulation of the Universe)
2023年12月31日:揭示计画的宇宙模拟影片-(Illustris: A Simulation of the Universe)--原图下载2023 December 31 {mtitle title="揭示计画的宇宙模拟影片"/}Video Credit: Illustris Collaboration, NASA, PRACE, XSEDE, MIT,Harvard CfA; Music: The Poisoned Princess (Media Right Productions)说明: 我们是怎么来的?请点选"播放",来观看这部攸关宇宙演化的电脑模拟,以及它对星系形成和人类在宇宙中该如何定位所提出的见解。揭示计画(the Illustris project)在2014年,动用了2千万个计算元运算时数,追蹤边长3千5百万光年的立方体内,120亿个组成元在130亿年期间的演化。在这项模拟里,科学家追蹤物质如何形成各式各样的星系。随着虚拟宇宙演化,部份随着宇宙膨胀的物质,很快地在重力的作用下聚成丝状天体、星系和星系团。这部主题影片以虚拟环绕相机的观点,呈现变动的局部宇宙里的一些天体。首先是暗物质的演化,接着是不同温度下的氢气云(0:45)如何变化,然后是氦和碳这类重元素的形成(1:30),最后再回到暗物质(2:07)。影格的左下角明列大爆炸后的时间,而右下角则标示所呈现的物质类别。爆发事件(例如在0:50),则呈现被星系核心超大质量黑洞喷出的泡状炽热气体。而揭示计画宇宙和真实宇宙所存在的有趣差异,也是研究的课题,诸如为何这项模拟会产生过量的年老恒星。{lamp/}原文:{mtitle title="Illustris: A Simulation of the Universe"/}Video Credit: Illustris Collaboration, NASA, PRACE, XSEDE, MIT,Harvard CfA; Music: The Poisoned Princess (Media Right Productions)Explanation: How did we get here?Click play, sit back, and watch. A computer simulation of the evolution of the universe provides insight into how galaxies formed and perspectives into humanity's place in the universe. The Illustris project exhausted 20 million CPU hours in 2014 following 12 billion resolution elements spanning a cube 35 million light years on a side as it evolved over 13 billion years.The simulation tracks matter into the formation of a wide variety of galaxy types.As the virtual universe evolves, some of the matter expanding with the universe soon gravitationally condenses to form filaments, galaxies, and clusters of galaxies.The featured video takes the perspective of a virtual camera circling part of this changing universe, first showing the evolution of dark matter, then hydrogen gas coded by temperature (0:45), then heavy elements such as helium and carbon (1:30), and then back to dark matter (2:07).On the lower left the time since the Big Bang is listed, while on the lower right the type of matter being shown is listed. Explosions (0:50) depict galaxy-center supermassive black holes expelling bubbles of hot gas.Interesting discrepancies between Illustris and the real universe have been studied, including why the simulation produced an overabundance of old stars.
2023年12月31日
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2023-11-08
2023年11月08日:欧几里得太空望远镜的英仙星系团-(Perseus Galaxy Cluster from Euclid)
2023年11月08日:欧几里得太空望远镜的英仙星系团-(Perseus Galaxy Cluster from Euclid)--原图下载{mtitle title="欧几里得太空望远镜的英仙星系团"/}Image Credit & License: ESA, Euclid, Euclid Consortium, NASA;Processing: Jean-Charles Cuillandre (CEA Paris-Saclay) & Giovanni Anselmi;Text: Jean-Charles Cuillandre说明: 天空新增了一部名为欧几里得(Euclid)的太空望远镜。欧几里得配备了两部大型的全景相机,用以捕捉从可见光到近红外光的讯息。拥有直径1.2米主镜的欧几里得望远镜,通过锐利的光学系统进行5个小时的持续观测,才拍下了这幅呈现2.5亿光年外英仙星系团里的1,000多个星系之影像。此外,这张影像还记录了10多万个背景星系,有些甚至远在100亿光年之外。欧几里得望远镜的创新性,在于它超过2倍满月面积的宽视场、其6.2亿像素相机所带来的高角度解析率、以及它的红外光视力,更难得的是能同时取得影像和光谱资讯。欧几里得望远镜初步计划要勘测3分之1的天空,并记录超过20亿个星系,以进行暗物质和暗能量是如何塑造我们宇宙的研究。{lamp/}原文:{mtitle title="Perseus Galaxy Cluster from Euclid"/}Image Credit & License: ESA, Euclid, Euclid Consortium, NASA;Processing: Jean-Charles Cuillandre (CEA Paris-Saclay) & Giovanni Anselmi;Text: Jean-Charles CuillandreExplanation: There's a new space telescope in the sky: Euclid.Equipped with two large panoramic cameras, Euclid captures light from the visible to the near-infrared. It took five hours of observing for Euclid's 1.2-meter diameter primary mirror to capture, through its sharp optics, the 1000+ galaxies in the Perseus cluster, which lies 250 million light years away. More than 100,000 galaxies are visible in the background, some as far away as 10 billion light years.The revolutionary nature of Euclid lies in the combination of its widefield of view (twice the area of the full moon), its high angular resolution(thanks to its 620 Megapixel camera), and its infrared vision, which captures both images and spectra. Euclid's initial surveys, covering a third of the sky and recording over 2 billion galaxies, will enable a study of how dark matter and dark energy have shaped our universe.
2023年11月08日
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2023-09-12
2023年09月12日:星系团Abell 370及后方的天体-(Galaxy Cluster Abell 370 and Beyond)
2023年09月12日:星系团Abell 370及后方的天体-(Galaxy Cluster Abell 370 and Beyond)--原图下载{mtitle title="星系团Abell 370及后方的天体"/}Image Credit: NASA,ESA,Jennifer Lotz and theHFF Team(STScI)说明: 这幅清晰的哈伯太空望远镜影像,捕捉到40多亿光年远处的大质量星系团Abell 370之身影。乍看之下,这个星系团里最醒目的天体为2个庞大的椭圆星系和无所不在之暗淡光弧。其实,散布在视野各处、更为昏暗的泛蓝光弧和影像中左下方引人注目的龙形光弧,是远在Abell 370后方的星系之身影。这些距离约远上2倍、原来不可见的星系之星光,受到星系团内以暗物质为主的庞大重力质量之会聚与扭曲,让我们得以隐约窥见这些早期宇宙的星系。这种称为重力透镜效应的现象,是爱因斯坦于1百多年前预言,在时空扭曲的状况下会产生的景观。远在影像右下方带芒银河恒星后方的Abell 370,位在鲸鱼座方向。这个星系团,是前沿星场计画所探索的6个星系团中的最后一个。{lamp/}原文:{mtitle title="Galaxy Cluster Abell 370 and Beyond"/}Image Credit: NASA,ESA,Jennifer Lotz and theHFF Team(STScI)Explanation: Some 4 billion light-years away, massive galaxy cluster Abell 370is captured in this sharpHubble Space Telescope snapshot.The cluster of galaxies onlyappears to be dominated by two giant elliptical galaxiesand infested with faint arcs.In reality, the fainter, scattered bluish arcs, along with thedramatic dragon arcbelow and left of center, are images of galaxies that liefar beyond Abell 370.About twice as distant, their otherwise undetected light ismagnified and distorted by the cluster's enormous gravitational mass,overwhelmingly dominated by unseendark matter.Providing atantalizing glimpseof galaxies in the early universe, the effect is known as gravitationallensing.A consequence of warpedspacetime, lensing waspredicted by Einstein almost a century ago.Far beyondthe spiky foreground Milky Way star at lower right,Abell 370 is seen toward the constellation Cetus, the Sea Monster.It was the last of six galaxy clusters imaged in theFrontier Fields project.
2023年09月12日
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2022-05-11
2022年05月11日:重力的笑容-(Gravity's Grin)
2022年05月11日:重力的笑容-(Gravity's Grin)--原图下载{mtitle title="重力的笑容"/}Image Credit: X-ray - NASA / CXC /J. Irwin et al. ;Optical - NASA/STScI说明: 在100多年前,爱因斯坦所发表的广义相对论预言了重力透镜现象。而正也是这种现象,把这些遥远星系弄成了这付怪诞的模样,更为这张结合钱德拉天文卫星的X射线和哈伯望远镜的可见光数据之影像,带来了爱丽斯魔镜之旅的风貌。在影像里,暱称为柴郡猫星系群的两个大型椭圆星系,周围环绕着容易让人引发联想的光弧。这些可见光弧,是遥远背景星系受到包括暗物质在内的星系群所有质量之重力聚焦,所形成的蜃影。实际上,构成“眼睛”的二个大型椭圆星系,分别是合併中的二个星系群最明亮的成员。因为它们碰撞的相对速率高达每秒1,350公里,是以气体被加热到数百万度,因而辐射出被渲染成紫色的X射线辉光。对星系群合併更好奇了吗?柴郡猫星系群是在大熊座内、距离约46亿光年之远处露齿微笑。(through the looking glass 爱丽斯魔镜之旅; Cheshire Cat galaxy group 柴郡猫星系群){lamp/}原文:{mtitle title="Gravity's Grin"/}Image Credit: X-ray - NASA / CXC /J. Irwin et al. ;Optical - NASA/STScIExplanation: AlbertEinstein'sgeneral theory of relativity, published over 100 yearsago, predicted the phenomenon of gravitational lensing.And that's what gives these distant galaxies such a whimsicalappearance,seenthrough the looking glass of X-ray and opticalimage data from the Chandra and Hubble space telescopes.Nicknamed the Cheshire Cat galaxy group, the group's twolarge elliptical galaxies are suggestively framed by arcs.The arcs are optical imagesof distant background galaxieslensed by the foreground group's total distributionof gravitational mass.Of course, that gravitational mass is dominatedby dark matter.The two large elliptical "eye" galaxies representthe brightest members of their own galaxy groups which are merging.Their relative collisional speed of nearly 1,350 kilometers/secondheats gas to millions of degrees producing the X-ray glow shownin purple hues.Curiouser aboutgalaxy group mergers?The Cheshire Catgroupgrinsin the constellation Ursa Major, some 4.6 billion light-years away.
2022年05月11日
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2021-10-31
2021年10月31日:模拟宇宙里的暗物质-(Dark Matter in a Simulated Universe)
2021年10月31日:模拟宇宙里的暗物质-(Dark Matter in a Simulated Universe)--原图下载{mtitle title="模拟宇宙里的暗物质"/}Illustration Credit & Copyright: Tom Abel & Ralf Kaehler (KIPAC, SLAC), AMNH说明: 我们的宇宙在闹鬼吗?因为,在这张暗物质图里看似如此。不可见暗物质所产生的重力,是星系自转为何如此高速、星系绕星系团公转为何如此快速、重力透镜偏折光线的能力为何这么强、和可见物质在近域宇宙和宇宙 微波背景上的分布为何如此,最广为接受的解释。上面这幅由美国自然历史博物馆.海登天文馆提供的主题图示,突显了在某种暗物质宇宙里,无所不在的暗物质如何影响我们的宇宙。在这张宇宙的细緻电脑模拟图里,无处不在的複杂丝缕状黝黑暗物质,像蜘蛛网般穿梭在宇宙里,其中橘色的斑块,是我们熟悉但相对少见的重子物质。这类电脑模拟,在统计学上和天文观测相当接近。但最让我们惊吓的是,儘管暗物质极为怪异,而且其形式不明,但在我们的认知里,已不再是宇宙中最奇怪的重力源了。这个头衔得让给暗能量,一种目前看似主宰整个宇宙扩张,分布也较均匀的排斥性重力源。{lamp/}原文:{mtitle title="Dark Matter in a Simulated Universe"/}Illustration Credit & Copyright: Tom Abel & Ralf Kaehler (KIPAC, SLAC), AMNHExplanation: Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters so fast, why gravitational lenses so strongly deflect light, and why visible matter is distributed as it is both in the local universe and on the cosmic microwave background. The featured image from the American Museum of Natural History's Hayden Planetarium Space Show Dark Universe highlights one example of how pervasive dark matter might haunt our universe. In this frame from a detailed computer simulation, complex filaments of dark matter, shown in black, are strewn about the universe like spider webs, while the relatively rare clumps of familiar baryonic matter are colored orange.These simulations are good statistical matches to astronomical observations. In what is perhaps a scarier turn of events, dark matter -- although quite strange and in an unknown form -- is no longer thought to be the strangest source of gravity in the universe.That honor now falls to dark energy, a more uniform source of repulsive gravity that seems to now dominate the expansion of the entire universe.
2021年10月31日
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2020-12-16
2020年12月16日:声化:子弹星系团的物质-(Sonified: The Matter of the Bullet Cluster)
2020年12月16日:声化:子弹星系团的物质-(Sonified: The Matter of the Bullet Cluster)--原图下载2020 December 16 {mtitle title="声化:子弹星系团的物质"/}Image Credit: X-ray: NASA/CXC/SAO; Optical: NASA/STScI, Magellan/U.Arizona; Lensing Map: NASA/STScI, ESO WFI, Magellan/U.Arizona; Sonification: NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida)说明: 子弹星系团有何重要性?这个大质量星系团(1E 0657-558)的重力透镜扭曲背景星系的方式,被引为支持"暗物质存在于星系团内学说"的强烈证据。然而不同的分析指出,不需要引进暗物质,只使用没那么炫的修正重力理论,就能够解释星系团的动力学行为,并且提出了较可能的前导过程。目前这二种科学假说正在争夺观测的诠释权,所以这是一场不可见暗物质与修正重力理论的对战。暗物质学派如果能找到颠扑不破的例证,就能击退简洁的修正重力理论。在这幅整合哈伯/钱德拉/麦哲伦观测数据的主题声化影像里,红色代表X射线数据,蓝色区块可能就是分落在两侧的暗物质。在此则声化处理里,低音代表暗物质,中音为可见光,而高音则是X射线。不过,随着针对子弹星系团的新观测、电脑模拟和数据分析逐渐出炉,这场争论仍会持续下去。{lamp/}原文:{mtitle title="Sonified: The Matter of the Bullet Cluster"/}Image Credit: X-ray: NASA/CXC/SAO; Optical: NASA/STScI, Magellan/U.Arizona; Lensing Map: NASA/STScI, ESO WFI, Magellan/U.Arizona; Sonification: NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M. Russo, A. Santaguida)Explanation: What's the matter with the Bullet Cluster?This massive cluster of galaxies (1E 0657-558) creates gravitational lens distortions of background galaxies in a way that has been interpreted as strong evidence for the leading theory: that dark matter exists within.Different analyses, though, indicate that a less popular alternative -- modifying gravity-- could explain cluster dynamics without dark matter, and provide a more likely progenitor scenario as well.Currently, the two scientific hypotheses are competing to explain the observations: it's invisible matter versus amended gravity.The duel is dramatic as a clear Bullet-proof example of dark matter would shatter the simplicity of modified gravity theories. The featured sonified image is a Hubble/Chandra/Magellan composite with red depicting the X-rays emitted by hot gas, and blue depicting the suggested separated dark matter distribution. The sonification assigns low tones to dark matter, mid-range frequencies to visible light, and high tones to X-rays. The battle over the matter in the Bullet cluster is likely to continue as more observations, computer simulations, and analyses are completed.
2020年12月16日
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