Euclid space telescope's 1st results reveal 'a goldmine of data' in search for dark matter and dark energy (images, video)

欧几里得空间望远镜的首批成果，为暗物质与暗能量研究带来海量珍贵数据（含图片、视频）。

The day that astronomers have been waiting for is here. On Wednesday (March 19), the European Space Agency (ESA) spacecraft Euclid released its first data to the public and to the scientific community.

天文学家们翘首以盼的日子终于到来。3月19日星期三，欧几里得空间望远镜向公众和科学界发布了首批数据。

This data includes three stunning previews of the deep-field space images that Euclid will produce. Within these deep fields are hundreds of thousands of galaxies of different shapes and sizes, revealing a tantalizing hint at the large-scale structure of the cosmos within the so-called "cosmic web." The data includes the classification survey of 380,000 galaxies, 500 new gravitational lens candidates, and a wealth of other cosmic bodies like galaxy clusters and active galactic nuclei.

这批数据包含欧几里得空间望远镜所拍摄的三幅令人震撼的深场空间图像预览。从这些深场图像中，可以观测到数十万个形态各异、大小不一的星系，它们为我们揭示了宇宙在所谓“宇宙网”中大尺度结构的诱人线索。此外，数据中还包括对38万个星系的分类调查，500个新的引力透镜候选体，以及大量其他宇宙天体，如星系团和活动星系核等。

Euclid must observe such a wide population of galaxies if scientists are to use its data to crack the mysteries of the "dark universe," the collective name for dark matter and dark energy. Euclid's potential to make a difference in this quest has led ESA scientists to dub the spacecraft their "dark universe detective." But this first data release shows that Euclid is capable of delivering so much more.

若想借助欧几里得空间望远镜的数据揭开“暗宇宙”（暗物质与暗能量的总称）的神秘面纱，科学家们就必须利用它来观测数量庞大的星系群体。欧几里得在这一探索中所具备的潜力，使得欧洲航天局的科学家们将其誉为“暗宇宙侦探”。不过，此次首批数据的发布表明，欧几里得空间望远镜具备的能力远超于此。

"I think the two biggest questions that we ask ourselves as humanity is, are we alone in the universe, and how does the universe work?" Carole Mundell, ESA director of science, said at a press conference held on Monday (March 17). "What are the fundamental laws of physics?"

“我认为，人类一直在思考的两个最大问题是：我们在宇宙中是否孤独？宇宙是如何运作的？” 欧洲航天局科学部主任卡罗尔·蒙德尔在3月17日星期一举行的新闻发布会上说，“物理学的基本规律又是什么？”

Mundell added that as our understanding of the universe has developed over many years, we have come to understand that the "ordinary matter" that composes stars, planets, moons, asteroids, our bodies, and everything we see around us composes only 5% of the universe's total matter and energy.

蒙德尔补充道，随着我们对宇宙的认识在多年间不断深化，我们逐渐明白，构成恒星、行星、卫星、小行星、我们的身体以及周围一切事物的“普通物质，“仅占宇宙总物质和能量的5%。

"The other 95% is dark and is unknown," she continued.

“其余的95%则是黑暗的，尚未被我们所知晓，”她接着说道。

These dark elements of the cosmos have come to be known as dark energy, a mysterious force that causes the expansion of the universe to accelerate and accounts for around 70% of the universe's matter and energy budget and dark matter (the outstanding 25% of the universe's matter/energy budget) strange "stuff" that outweighs ordinary matter by 5 to 1 in the cosmos, but remains invisible because it doesn't interact with light.

宇宙中这些暗元素被称为暗能量，这是一种神秘力量，导致宇宙加速膨胀，占宇宙总物质和能量的约70%。而暗物质则占宇宙总物质和能量预算中剩余的25%，是一种奇怪的“物质”，其在宇宙中的质量是普通物质的5倍，但由于不与光相互作用而始终不可见。

"The whole purpose of Euclid is really to put those two together to understand the nature of dark matter and dark energy and how they're coupled in the universe," Mundell said. "Really, Euclid is not only a dark universe detective, it's also a time machine. We will look back 10 billion years in cosmic history."

“欧几里得的全部意义在于将这两者结合起来，以理解暗物质和暗能量的本质，以及它们在宇宙中的相互作用，”蒙德尔说，“实际上，欧几里得不仅是‘暗宇宙侦探’，它还是台‘时间机器’。我们将回溯宇宙历史的100亿年。”

For this first data release, Euclid, which launched in July 2023 and began observations proper in Feb. 2024, spent just one week scanning three patches of the sky over which it will make its deepest observations in the future.

在此次首批数据发布中，于2023年7月发射、2024年2月正式开始观测的欧几里得空间望远镜，仅用了一周时间来扫描三片天空区域，而未来它将在这些区域进行最深入的观测。

Performing just one scan of each of these regions thus far, Euclid was able to observe 26 million galaxies, the furthest and thus earliest of which is around 10.5 billion light-years away. The observations also contain a small sample of quasars, the bright hearts of active galaxies powered by feeding supermassive black holes, which, because of their incredible luminosity, can be seen even further away.

截至目前，欧几里得空间望远镜对每个区域仅进行了一次扫描，便已观测到2600万个星系，其中最遥远、也是最早期的星系距离我们约105亿光年。观测结果中还包含了一小部分类星体样本，类星体是活动星系明亮的核心，由超大质量黑洞吞噬物质提供能量。因其极高的亮度，类星体能够被我们从更远的距离观测到。

While Euclid will pass over these patches many more times before its primary mission draws to a close in 2030, the first glimpse of these areas, about as wide in the sky as 300 full moons, provides an awe-inspiring preview of the sheer scale of the cosmic atlas that Euclid will build. By mission completion, this atlas will cover around one-third of the entire night sky over Earth.

在2030年主要任务结束前，欧几里得空间望远镜还会多次飞越这些区域。目前，我们看到的首批图像覆盖了天空中约300个满月大小的区域，为欧几里得将构建的宇宙地图规模提供了一个令人敬畏的预览。到任务完成时，这张宇宙地图将覆盖地球上整个夜空的约三分之一。

The three deep fleids observed by Euclid are Euclid Deep Field North, Euclid Deep Field Fornax, and Euclid Deep Field South.

欧几里得空间望远镜观测的三个深场分别是：欧几里得北天深场、欧几里得炉座深场和欧几里得南天深场。

Below is the image Euclid captured of Euclid Deep Field North containing over 10 million galaxies, the Cat’s Eye Nebula (center-left), a stellar remnant around 3,000 light-years away, and a large group of galaxies dominated by the large galaxy NGC 6505 right of center). Euclid will make a total of 32 sweeps of this region of the sky before 2030.

欧几里得空间望远镜拍摄的欧几里得北天深场图像中包含超过1000万个星系。在图像中心左侧是猫眼星云，这是一个距离地球约3000光年的恒星遗迹。图像中心右侧则是一个由大型星系NGC 6505主导的星系群。在2030年之前，欧几里得望远镜将对该区域进行共计32次扫描。

The next image represents Euclid's first look at the region dubbed Euclid Deep Field Fornax, in which it has already seen 4.5 million galaxies. Over the next six years, Euclid will make 52 observations of this region of space.

下图是欧几里得空间望远镜首次观测到的“欧几里得炉座深场”区域，目前已观测到450万个星系。在未来的六年里，欧几里得望远镜将对该区域进行52次观测。

Euclid Deep Field Fornax contains the smaller Chandra Deep Field South region which has been studied by NASA's Chandra and ESA's XMM-Newton X-ray observatories, in addition to the Hubble Space Telescope and major ground-based telescopes.

欧几里得炉座深场包含较小的钱德拉南天深场区域，该区域曾被美国宇航局的钱德拉X射线天文台、欧洲航天局的XMM-牛顿X射线天文台、哈勃太空望远镜以及主要的地面望远镜研究过。

Less well-studied is Euclid Deep Field South (below), which has not been assessed by any other deep sky survey thus far. That means this region, also Euclid's largest deep field, has a vast potential for new, exciting discoveries.

相比之下，欧几里得南天深场（如下图）的研究程度较低，尚未被其他任何深空巡天项目评估过。这意味着这片区域，同时也是欧几里得最大的深场，蕴含着巨大潜力，可能带来令人兴奋的新发现。

The space telescope has already spotted more than 11 million galaxies in this field. Additionally, in this field, Euclid observed hints at a large-scale structure of the universe called the cosmic web, consisting of threads of gas and dark matter stretching between clusters of galaxies.

欧几里得空间望远镜已经在该区域观测到超过1100万个星系。此外，在这片区域，欧几里得还观测到了被称为宇宙网的宇宙大尺度结构的线索，这种结构由星系团之间延伸的气体和暗物质丝状结构组成。

"It's impressive how one observation of the deep field areas has already given us a wealth of data that can be used for a variety of purposes in astronomy: from galaxy shapes to strong lenses, clusters, and star formation, among others," ESA Euclid project scientist Valeria Pettorino said. "We will observe each deep field between 30 and 52 times over Euclid's six-year mission, each time improving the resolution of how we see those areas and the number of objects we manage to observe.

欧核中心的欧几里得项目科学家瓦莱里娅·佩托里诺表示：“一次对深场区域的观测就已经为我们提供了大量数据，这些数据在天文学的许多领域都极具价值，从星系形状到引力透镜效应，再到星系团和恒星形成等等。”“在欧几里得六年的任务期间，我们将对每个深场区域进行30到52次观测，每次都会提高我们对这些区域的分辨率，以及我们能够观测到的天体数量。

"Just think of the discoveries that await us."

“想象一下等待我们的发现吧。”

Because dark matter's mass dominates galaxies, it plays a vital role in galactic evolution and, ultimately, the shapes these galaxies take. That means in order to probe the mysteries of dark matter, Euclid precisely must precisely observe the shape or "morphology" of billions of galaxies.

由于暗物质的质量在星系中占主导地位，它在星系演化以及最终星系形态的形成中起着关键作用。这意味着，为了探究暗物质的奥秘，欧几里得空间望远镜必须精确观测数十亿个星系的形态或“形态学”。

Because galaxies come together in a web of dark matter, forming large galaxy clusters, Euclid can also learn more about this mysterious stuff by measuring the distribution of the millions of galaxies visible in each of its deep fields.

由于星系是在暗物质构成的网络中聚集形成的，进而发展成大型星系团，因此欧几里得空间望远镜还可以通过测量其每个深场中数百万个可见星系的分布，来进一步了解这种神秘的暗物质。

Likewise, this distribution is also important to understand how dark energy has expanded the fabric of space, thus pushing these galaxies apart.

同样，这种分布对于理解暗能量如何扩展宇宙空间的结构，从而将这些星系推离彼此，也至关重要。

"The full potential of Euclid to learn more about dark matter and dark energy from the large-scale structure of the cosmic web will be reached only when it has completed its entire survey," Euclid Consortium scientist Clotilde Laigle said. "Yet the volume of this first data release already offers us a unique first glance at the large-scale organization of galaxies, which we can use to learn more about galaxy formation over time."

欧几里得联盟科学家克洛蒂尔德·莱格尔表示：“只有当欧几里得完成其全部巡天观测时，它从宇宙网的大尺度结构中进一步了解暗物质和暗能量的全部潜力才能得以实现。然而，这次首批数据发布的规模已经让我们得以初步窥探星系的大尺度分布，我们可借此逐步深入了解星系的形成历程。”

The observations of these galaxies in this first release alone constituted 35 terabytes of data collected over one week.

仅这批星系观测数据就达到35TB，是一周内收集到的。

"To give you a feeling that 35 terabytes of data are the equivalent of 200 days of video streaming at the highest quality," Pettorino said on Monday. "If you watch TV on your HDR, 4k with 60 frames per second for 200 days, then you would be that would be the equivalent of 35 terabytes."

“为了让您有个概念，35太字节的数据相当于以最高质量连续播放200天的视频，”佩托里诺在周一表示，“如果你用HDR、4K、每秒60帧的设置在电视上看200天，那么这就是35太字节数据的量。”

The ESA project scientist added that next year, Euclid will release its first year of observations. This will be 2 petabytes of data, equal to streaming 31 years of 4K TV, Pettorino continued, advising against engaging in such a binge watch.

欧核中心的欧几里得项目科学家补充说，明年，欧几里得将发布其第一年的观测数据。这将是2拍字节的数据，相当于播放31年的4K电视节目，佩托里诺继续说道，并建议不要尝试这样的连续观看。

The stunning zoomed-in image of the Euclid Deep Field South below shows various galaxy clusters and the light between these galaxies, so-called "intracluster light." The image represents a 70-times zoom-in on the original mosaic, demonstrating why so much data is gobbled up in these Euclid images.

下面这张令人惊叹的欧几里得南天深场放大图，展示了众多星系团以及星系之间的光，即所谓的“星系团内光”。这张图是对原始拼接图70倍放大后的效果，也解释了为何欧几里得的图像会消耗如此多的数据。

Euclid consortium member Mike Walmsley of the University of Toronto explained that no human could possibly hope to analyze all of this data, so scientists have turned to artificial intelligence (AI) to perform and initially filter this data, picking out galaxies for further investigation.

多伦多大学的欧几里得联盟成员迈克·沃尔姆斯利解释说，没有人能够手动分析所有这些数据，因此科学家们借助人工智能来处理和初步筛选数据，挑选出值得进一步研究的星系。

The galaxies the AI selects are then passed along to citizen scientists for them to identify aspects of these galaxies, such as their shape and brightness and characteristics like spiral arms, central bars, and tidal tails, the latter of which indicate merging galaxies.

人工智能挑选出的星系将交给公民科学家，由他们来识别这些星系的形状、亮度，以及螺旋臂、中心条和潮汐尾等特征，其中潮汐尾表明星系正在合并。

"We're at a pivotal moment in terms of how we tackle large-scale surveys in astronomy. AI is a fundamental and necessary part of our process in order to fully exploit Euclid's vast dataset," Walmsley added. "We're building the tools as well as providing the measurements. In this way, we can deliver cutting-edge science in a matter of weeks, compared with the years-long process of analyzing big surveys like these in the past."

“在天文学的大规模巡天观测方面，我们正处于一个关键的转折点。为了充分利用欧几里得望远镜庞大的数据集，人工智能是不可或缺的重要工具，” 沃尔姆斯利补充道。“我们不仅在开发相关工具，还提供测量数据。通过这种方式，我们可以在几周内完成尖端科学研究，而过去分析类似的大规模巡天数据则需要耗费数年时间。”

The Euclid consortium will need all the help it can get, the galaxies featured in the data released thus far represent just 0.4% of the total number of galaxies of similar resolution expected to be imaged over Euclid's lifetime.

欧几里得联盟将需要尽可能多的帮助，目前发布的数据中包含的星系仅占欧几里得整个使用寿命期间预计成像的类似分辨率星系总数的0.4%。

"We're looking at galaxies from inside to out, from how their internal structures govern their evolution to how the external environment shapes their transformation over time," added Laigle. "Euclid is a goldmine of data, and its impact will be far-reaching, from galaxy evolution to the bigger-picture cosmology goals of the mission."

“我们从星系的内部和外部来研究它们，从它们的内部结构如何主宰其演化，到外部环境如何塑造它们随时间的转变，”莱格尔补充道。“欧几里得空间望远镜是一个数据宝库，其影响将十分深远，无论是在星系演化方面，还是在任务的宏观宇宙学目标上。”

One of the most exciting aspects of this first Euclid data release is the revelation of extraordinary events in spacetime called "gravitational lenses." These distortions of distant objects occur when light from a background object passes a massive object, like a galaxy or galaxy cluster, that comes between it and Earth.

此次欧几里得数据首发最令人兴奋的亮点之一，便是揭示了时空中被称为“引力透镜”的非凡现象。当来自背景天体的光线经过位于其与地球之间的 massive 天体（如星系或星系团）时，会因引力作用发生弯曲，从而导致远处物体的图像出现扭曲。

Because objects with mass cause the very fabric of space and time to warp (that's general relativity, folks) when light passes these intervening objects it is also curved. the closer to the body of mass, the gravitational lens, light passes, the more extreme its curvature.

物体有质量就会使时空扭曲（这就是广义相对论，朋友们），当光线经过这些中介天体时，也会发生弯曲。光线经过引力透镜（即大质量天体）越近，其弯曲程度就越剧烈。

That means that light from the same background object can reach Earth (or Euclid) at different times. This can either amplify these background objects— hence, the term "lensing"— or it can cause the same background object to appear distorted, stretched like taffy, or in multiple places in the same image, forming patterns like arcs or circles called "Einstein rings."

这意味着，来自同一背景天体的光可能在不同时间到达地球（或欧几里得望远镜）。这会放大背景天体的像——因此得名“透镜”效应——或者导致同一背景天体在图像中出现扭曲、像拉伸的太妃糖，或者在图像中形成多个像，呈现出类似弧形或圆环的图案，即所谓的“爱因斯坦环”。

Euclid had already spotted a stunning Einstein ring, which was revealed to the public back in Feb. this year, but following the analysis of this new week's worth of data, AI and citizen scientists uncovered a further 500 examples of galaxy gravitational lenses amplifying light from a distant background galaxy. Lenses like this are rare because both the background galaxy and the lensing galaxy have to be perfectly aligned from Earth for this effect to work.

欧几里得望远镜已经捕捉到了一个令人惊艳的爱因斯坦环，这一发现早在今年2月就已公之于众。然而，在对最近一周的数据进行分析后，人工智能和公民科学家又发现了500个新的星系引力透镜实例，这些透镜效应放大了来自遥远背景星系的光线。这样的引力透镜极为罕见，因为要产生这种效应，背景星系和透镜星系必须从地球的视角来看恰好完美对齐。

Almost all of these new Euclid gravitational lens arrangements were previously unknown.

欧几里得望远镜此次发现的几乎全部引力透镜组合此前都未被知晓。

"Until now, the vast majority of lenses have been found by ground-based telescopes. that is because lenses are so rare you need vast chunks of the sky to find them, and we simply haven't had a space telescope with the area and the resolution and the sensitivity to do that," Walmsley said. "Euclid is the first space telescope which can find a large number of lenses from space."

“迄今为止，绝大多数引力透镜都是通过地面望远镜发现的。这是因为引力透镜极为罕见，需要观测大面积的天空才能找到，而我们之前一直缺乏具有足够观测面积、分辨率和灵敏度的太空望远镜来完成这项工作。”沃尔姆斯利说道，“欧几里得是第一台能够从太空中发现大量引力透镜的太空望远镜。”

By its release next year alone, Euclid is expected to have found 7,000 gravitational lens candidates. By the time its mission concludes in 2030, the Euclid consortium expects the dark universe detective spacecraft to have uncovered somewhere in the region of 100,000 galaxy-galaxy-strong lenses. That is around 100 times more strong gravitational lenses than is currently known.

仅在明年发布的数据中，欧几里得望远镜预计就将发现7000个引力透镜候选体。到2030年任务结束时，欧几里得联盟预计这台暗宇宙侦探航天器将揭示大约10万个星系-星系强引力透镜。这比目前已知的强引力透镜数量多了大约100倍。

Euclid will also be on the hunt for weakly lensed background galaxies with more subtle distortions. These distortions are too subtle to be seen in individual galaxies but can be detected when considering large samples of background sources. Weak lensing is key to investigating the warping of spacetime due to the distribution of invisible dark matter in lensing galaxies.

欧几里得望远镜还将搜寻那些背景星系被更微妙地扭曲的弱引力透镜效应实例。这种扭曲过于细微，难以在单个星系中察觉，但当考虑大量背景源样本时便能被探测到。弱引力透镜效应对于研究因透镜星系中不可见暗物质的分布而导致的时空扭曲至关重要。

"This is a tiny taste of what's to come, but tiny is not the right word," Mundell concluded. "Scientists have a lot of work ahead of them in the next six years, but it's going to be phenomenally exciting and very, very interesting, groundbreaking work."

“这只是未来的一小部分，但‘小’这个词其实并不合适，”蒙德尔总结道。“科学家们在接下来的六年里有很多工作要做，但这将是极其令人兴奋的、非常有趣且具有开创性的工作。”

The three deep field preview from Euclid can now be explored in ESASky. Euclid Deep Field South is here, Euclid Deep Field Fornax: here and Euclid Deep Field North: here.

欧几里得的三个深场预览现可在ESASky上探索。欧几里得南天深场位于此处，欧几里得炉座深场位于此处，欧几里得北天深场位于此处。

The 36 scientific papers that emerged from this first data drop from Euclid are available here.

欧几里得望远镜首批数据催生的36篇科学论文可在此查阅。

And you fancy joining the 9976 citizen scientists of the GalaxyZoo, who helped classify the galaxies in Euclid's first deep field images, check out the Zooiverse website of the project here.

如果你也想加入GalaxyZoo，成为帮助分类欧几里得深场图像中星系的9976名公民科学家之一，可以访问该项目的Zooiverse网站。在这里，你可以参与到星系的分类工作中，为天文学研究贡献一份力量。