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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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欢迎来到人生天地间
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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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2017年08月06日:银河与炸裂的流星-(Milky Way and Exploding Meteor)
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2024年02月11日:直指月亮的火箭烟尘影子-(Rocket Plume Shadow Points to the Moon)
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2021-06-23
2021年06月23日:星力的恆星形成模拟-(STARFORGE: A Star Formation Simulation)
2021年06月23日:星力的恆星形成模拟-(STARFORGE: A Star Formation Simulation)--原图下载2021 June 23 {mtitle title="星力的恆星形成模拟"/}Video & Text Credit: Michael Y. Grudić (Northwestern U.) et al., STARFORGE Collaboration; Music: Prelude, Op. 28, No. 4 in E Minor (Frédéric Chopin)说明: 恒星是如何形成的?恒星大多形成于星系盘面的巨分子云之内。而恒星形成过程的触发、影响及限制因子,则为恒星风、喷流、高能星光、和先前世代恒星的超新星爆炸。这部来自星力计算模拟的主题影片,呈现在一团质量为20,000倍太阳的气体云里,这些因子的複杂交互作用。在这部缩时的视象化影片里,较淡色的区域气体密度较高,色彩则标示气体的速率(紫色较慢,橙色为高速),而点为新形成恒星的位置。在这部影片开头时,一团宽约50光年的气体云,在本身重力的作用下开始聚集。在2百万年内,第一批恒星形成,而且新诞生的大质量恒星发出让人印象深刻的喷流。这项模拟定格在4百30万年,然后整个体积旋转提供3维视角。关于恒星形成目前还有非常多的未知,包括喷流在限制后续形成的恒星之质量所扮演的角色。(STARFORGE simulation 星力模拟){lamp/}原文:{mtitle title="STARFORGE: A Star Formation Simulation"/}Video & Text Credit: Michael Y. Grudić (Northwestern U.) et al., STARFORGE Collaboration; Music: Prelude, Op. 28, No. 4 in E Minor (Frédéric Chopin)Explanation: How do stars form? Most form in giant molecular clouds located in the central disk of a galaxy. The process is started, influenced, and limited by the stellar winds, jets, high energy starlight, and supernova explosions of previously existing stars.The featured video shows these complex interactions as computed by the STARFORGE simulation of a gas cloud 20,000 times the mass of our Sun.In the time-lapse visualization, lighter regions indicate denser gas, color encodes the gas speed (purple is slow, orange is fast), while dots indicate the positions of newly formed stars.As the video begins, a gas cloud spanning about 50 light years begins to condense under its own gravity. Within 2 million years, the first stars form, while newly formed massive stars are seen to expel impressive jets.The simulation is frozen after 4.3 million years, and the volume then rotated to gain a three-dimensional perspective.Much remains unknown about star formation, including the effect of the jets in limiting the masses of subsequently formed stars.
2021年06月23日
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2021-05-18
2021年05月18日:项鍊星云的喷流-(Jets from the Necklace Nebula)
2021年05月18日:项鍊星云的喷流-(Jets from the Necklace Nebula)--原图下载{mtitle title="项鍊星云的喷流"/}Image Credit: ESA, Hubble, NASA; Processing: K. Noll说明: 那种天体会挂着项鍊呢?首先,分析指出项鍊星云是个行星状星云,是一颗恒星在生命末期所抛出的气体云。此外,项圈上看似钻石的结构,其实是正在散发明亮辉光的物质结。这幅哈伯太空望远镜主题影像所呈现的项鍊星云,中心看似只有单颗恒星,但它可能是2颗极端密近、并共享大气层的互绕恒星。而影像左上及右下的泛红气体云,则是受到源自中心的喷流激发而发光现身的天体。不过究竟这些明亮喷流是如何形成的,至今仍是研究的题材。如想观赏年龄5,000多年、宽约5光年的项鍊星云,最佳的方式是用大望远镜巡礼北天的天箭座。{lamp/}原文:{mtitle title="Jets from the Necklace Nebula"/}Image Credit: ESA, Hubble, NASA; Processing: K. NollExplanation: What celestial body wears the Necklace Nebula?First, analyses indicate that the Necklace is a planetary nebula, a gas cloud emitted by a star toward the end of its life.Also, what appears to be diamonds in the Necklace are actually bright knots of glowing gas. In the center of the Necklace Nebula are likelytwo stars orbiting so close together that they share a common atmosphere and appear as one in the featured image by the Hubble Space Telescope. The red-glowing gas clouds on the upper left and lower right are the results of jets from the center. Exactly when and how the bright jets formed remains a topic ofresearch. The Necklace Nebula is only about 5,000 years old, spans about 5 light years, and can best be found with a large telescope toward the direction of the constellation of the Arrow (Sagitta).
2021年05月18日
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2021-04-27
2021年04月27日:动画:黑洞如何摧毁恆星-(Animation: Black Hole Destroys Star)
2021年04月27日:动画:黑洞如何摧毁恆星-(Animation: Black Hole Destroys Star)--原图下载2021 April 27 {mtitle title="动画:黑洞如何摧毁恆星"/}Video Illustration Credit: DESY, Science Communication Lab说明: 恒星太靠近黑洞会怎样?黑洞会把恒星撕碎。然而,过程何似?关键并非重力有多强,而是恒星各区域受到的引力差(引潮力),才是恒星毁灭的主因。这部主题动画里,揭示了恒星碎裂的过程。在动画开头之时,可见到一颗往黑洞靠近的恒星。在它的轨道速率增加的同时,它的外层大气在最近距时被剥去。大部分的恒星大气最后会消散在太空中,只有部分会持续旋绕黑洞形成吸积盘。接着,动画带我们进入吸积盘,眺望中央的黑洞。除了重力透镜造成的奇特视觉效应之外,还可见到吸积盘的反侧。最后,我们的视线沿着二道顺自转轴外泛的喷流之一远眺。理论模型指出,这些喷流里不但应有高能气体,也有高能微中子,而在不久前,地面观测刚找到一个例证。{lamp/}原文:{mtitle title="Animation: Black Hole Destroys Star"/}Video Illustration Credit: DESY, Science Communication LabExplanation: What happens if a star gets too close to a black hole?The black hole can rip it apart -- but how?It's not the high gravitational attraction itself that's the problem -- it's the difference in gravitational pull across the star that creates the destruction. In the featured animated video illustrating this disintegration, you first see a star approaching the black hole. Increasing in orbital speed, the star's outer atmosphere is ripped away during closest approach. Much of the star's atmosphere disperses into deep space, but some continues to orbit the black hole and forms an accretion disk.The animation then takes you into the accretion disk while looking toward the black hole.Including the strange visual effects of gravitational lensing, you can even see the far side of the disk. Finally, you look along one of the jets being expelled along the spin axis. Theoretical models indicate that these jets not only expel energetic gas, but create energetic neutrinos -- one of which may have been seen recently on Earth.
2021年04月27日
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2021-04-21
2021年04月21日:半人马A的翘曲磁场-(Centaurus A's Warped Magnetic Fields)
2021年04月21日:半人马A的翘曲磁场-(Centaurus A's Warped Magnetic Fields)--原图下载{mtitle title="半人马A的翘曲磁场"/}Image Credit: Optical: European Southern Observatory (ESO) Wide Field Imager; Submillimeter: Max Planck Institute for Radio Astronomy/ESO/Atacama Pathfinder Experiment (APEX)/A.Weiss et al; X-ray and Infrared: NASA/Chandra/R. Kraft; JPL-Caltech/J. Keene; Text: Joan Schmelz(USRA)说明: 当星系互撞时,它们的磁场会受到什么影响?为得到答案,美国航太总署以波音747为平台的索菲亚天文台(SOFIA),观测半人马A极化尘埃发出的光,以找出它的磁场结构。半人马A不寻常的形状,源自二个星系的互撞,而受中心超大质量黑洞吸积的气体,则是驱动喷流的能源。在这幅主题影像里,由SOFIA得到的磁场线,叠加在ESO(可见光;白)、APEX(次毫米;橙)、钱德拉(X射线;蓝)和史匹哲(红外光;红)影像之上。影像里,星系外围的磁场平行于尘埃带,但中心附近则颇为扭曲。这是因为黑洞附近的重力加速离子,强化了该处的磁场。总结来说,星系互撞不但合併了星系的质量,也强化了它们的磁场。这些结果,让我们对星系合併较常发生的早期宇宙里,磁场如何演化有新的洞见。{lamp/}原文:{mtitle title="Centaurus A's Warped Magnetic Fields"/}Image Credit: Optical: European Southern Observatory (ESO) Wide Field Imager; Submillimeter: Max Planck Institute for Radio Astronomy/ESO/Atacama Pathfinder Experiment (APEX)/A.Weiss et al; X-ray and Infrared: NASA/Chandra/R. Kraft; JPL-Caltech/J. Keene; Text: Joan Schmelz(USRA)Explanation: When galaxies collide -- what happens to their magnetic fields?To help find out, NASA pointed SOFIA, its flying 747, at galactic neighbor Centaurus A to observe the emission of polarized dust -- which traces magnetic fields. Cen A's unusual shape results from the clash of two galaxies with jets powered by gas accreting onto a central supermassive black hole. In the resulting featured image, SOFIA-derived magnetic streamlines are superposed on ESO (visible: white), APEX (submillimeter: orange), Chandra (X-rays: blue), and Spitzer (infrared: red) images.The magnetic fields were found to be parallel to the dust lanes on the outskirts of the galaxy but distorted near the center. Gravitational forces near the black hole accelerate ions and enhance the magnetic field. In sum, the collision not only combined the galaxies’ masses -- but amplified their magnetic fields. These results provide new insights into how magnetic fields evolved in the early universe when mergers were more common.
2021年04月21日
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2021-04-09
2021年04月09日:星系M106-(Messier 106)
2021年04月09日:星系M106-(Messier 106)--原图下载{mtitle title="星系M106"/}Image Credit: NASA, Hubble Legacy Archive,Kitt Peak NationalObservatory;Amateur Data & ProcessingCopyright:Robert Gendler说明: 邻近大熊座,被猎犬座群星环绕的这个星系,是由公制推手、法国天文学家梅尚 发现于1781年。后来,他的朋友兼同事梅西叶把它纳入他编录的星表里,成为M106。近代的深空影像证实它是个宇宙岛,一个位在银河系众星后方,宽约3万光年,离我们只有2千1百万光年远的螺旋星系。除了鲜明的尘埃带和明亮的星系核之外,这幅整合业余及专业望远镜数据的精采组合影像,也突显了螺旋臂上的年轻泛蓝星团和泛红的恒星诞生区,以及由辉光氢气构成的精彩泛红喷流。 此外,在这幅影像里,可见到右下角的小伴星系NGC 4248,以及散布在影像各处的背景星系。M106 (亦称NGC 4258)是一个邻近的西佛型活跃星系,在电波至X射线的所有电磁波段都很明亮。活跃星的能源,据信是来自掉进大质量星系核心黑洞的物质。{lamp/}原文:{mtitle title="Messier 106"/}Image Credit: NASA, Hubble Legacy Archive,Kitt Peak NationalObservatory;Amateur Data & ProcessingCopyright:Robert GendlerExplanation: Close to the Great Bear(Ursa Major) and surrounded by the stars of theHunting Dogs(Canes Venatici), this celestial wonder wasdiscoveredin 1781 by themetricFrench astronomerPierre Mechain.Later, it was added to the catalog of his friend and colleagueCharles Messier asM106.Modern deep telescopic views reveal it to be anisland universe -a spiral galaxy around 30 thousand light-years across locatedonly about 21 million light-years beyond the stars of the Milky Way.Along with a bright central core, thisstunning galaxy portrait,a composite of image data from amateur and professional telescopes,highlights youthful blue star clusters and reddish stellar nurseriestracing the galaxy's spiral arms.It also shows off remarkable reddishjets ofglowing hydrogen gas.In addition to small companion galaxy NGC 4248 at bottom right,background galaxies can be found scattered throughout the frame.M106, also known as NGC 4258, is a nearby example of theSeyfert class of active galaxies, seenacross the spectrumfrom radio to X-rays.Active galaxies are powered by matter falling into a massivecentral black hole.
2021年04月09日
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2021-01-17
2021年01月17日:星系半人马座A的喷流-(Jets from Unusual Galaxy Centaurus A)
2021年01月17日:星系半人马座A的喷流-(Jets from Unusual Galaxy Centaurus A)--原图下载{mtitle title="星系半人马座A的喷流"/}Image Credit: ESO/<ahref="https://www.eso.org/public/teles-instr/lasilla/mpg22/wfi/">WFI (visible);MPIfR/<ahref="https://www.eso.org/public/">ESO/<ahref="http://www.apex-telescope.org/ns/">APEX/A. Weiss et al. (microwave);NASA/<ahref="https://cxc.harvard.edu/">CXC/<ahref="https://www.cfa.harvard.edu/">CfA/R. Kraft et al. (X-ray)说明: 这些源自星系半人马座A的喷流,长度超过1百万光年。这些在螺旋星系半人马座A核心超大质量黑洞的驱策下、喷涌而出的电浆喷流,更照亮了整个星系。不过,核心的黑洞到底是如何把掉入的物质排出来,目前仍然不明。在穿出星系之后,这些喷流造成了庞大,会持续散发数百万年辉光的电波泡。在数十亿年后的将来,如果受到通过附近的气体云之激发,这些电波泡甚至会重新点亮。在这张主题合成影像里,X射线波段的光以蓝色呈现,微波波段的光为橘色。其中,电波波段的影像,呈现了最中心1光年内的中央喷流 底部之细微结构。{lamp/}原文:{mtitle title="Jets from Unusual Galaxy Centaurus A"/}Image Credit: ESO/<ahref="https://www.eso.org/public/teles-instr/lasilla/mpg22/wfi/">WFI (visible);MPIfR/<ahref="https://www.eso.org/public/">ESO/<ahref="http://www.apex-telescope.org/ns/">APEX/A. Weiss et al. (microwave);NASA/<ahref="https://cxc.harvard.edu/">CXC/<ahref="https://www.cfa.harvard.edu/">CfA/R. Kraft et al. (X-ray)Explanation: The jets emanating fromCentaurus A are over a million light years long.These jets of streamingplasma,expelled by a giant black hole in the center of this spiral galaxy, light up this composite image ofCen A.Exactly how thecentral black holeexpels infalling matter remains unknown.After clearing the galaxy, however,the jets inflate largeradio bubbles that likely glow for millions of years.If energized by a passing gas cloud, the radio bubbles can even light up again after billions of years.X-ray light is depicted in thefeatured composite image in blue, whilemicrowave light is colored orange. The base of the jet in radio light showsdetails of the innermost light year of thecentral jet.
2021年01月17日
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