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Exclusive: ‘Like ripples on the sea’: Chinese astronomer tells Global Times how the Milky Way got its newly discovered ‘wrinkles’_我的网站
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Chinese astronomers have discovered that the Milky Way is not a simple, smoothly warped disk, but contains widespread "wrinkle-like" structures resembling ripples on a water surface, providing new clues to understanding the galaxy's 3D structure and evolutionary history.
The discovery was made by a research team from the Purple Mountain Observatory (PMO) under the Chinese Academy of Sciences, using data from the "Milky Way Imaging Scroll Painting" (MWISP) survey. The findings were published online titled "Widespread corrugations superimposed on the Galactic warp in the outer CO disk" in the journal Nature Astronomy on August 7.
For decades, astronomers have known that the Milky Way's disk is not perfectly flat. Instead, its outer regions are slightly bent upward on one side and downward on the other - a structure known as a galactic warp.
However, the latest study shows that this large-scale bending is not the whole story. Smaller-scale vertical fluctuations are also embedded within the warped disk, creating a more complicated 3D structure.
"In many illustrations and in the public imagination, the Milky Way looks like a flat vinyl record," Sun Yan, associate researcher at PMO and the first author of the paper, told the Global Times on Tuesday. "In reality, the outer part of the Milky Way is more like a record that has been heated and deformed, with one side lifted and the other side lowered. That is the warp. On top of this large-scale deformation, there are additional smaller waves, which we call corrugations," Sun explained.
Using a more everyday analogy, Sun compared the Milky Way's structure to a sea surface. The warp is like a large swell that changes the overall height of the ocean, while corrugations are smaller waves superimposed on that swell.
"The two structures exist together. In our data analysis, we first removed the large-scale warp model, which allowed us to reveal the smaller wave-like patterns hidden underneath," Sun said.
The research focused on the Milky Way's outer gas disk rather than the more familiar stellar disk. According to Sun, cold molecular gas and stars provide two complementary ways to study the galaxy.
"Molecular gas is a sensitive probe for studying the vertical structure and dynamics of the galactic disk because it is concentrated near the disk plane and responds strongly to disturbances," she said.
Molecular gas is also the raw material for star formation, meaning its distribution is closely connected with the formation of young stars. The researchers traced this gas through carbon monoxide (CO) emission, which can penetrate regions obscured by interstellar dust and provide a different perspective from optical observations of stars.
The breakthrough was made possible by the MWISP survey, conducted using China's 13.7-meter millimeter-wave telescope.
"MWISP can be understood as giving the Milky Way a large-scale medical examination using millimeter-wave observations," Sun said.
Previous CO surveys were limited in sensitivity and coverage, making it difficult to accurately study the distant outer regions of the galaxy. In contrast, the latest study identified more than 30,000 molecular cloud samples, covering about half of the Milky Way's outer disk and extending to a distance of about 26 kiloparsecs from the Galactic center.
With such a large dataset, researchers were able to first establish a model of the overall warp and then separate subtle structures from the background. The newly identified corrugations have radial wavelengths of about 3.9-7.9 kiloparsecs and vertical amplitudes of about 100-200 parsecs.
The study also identified a corrugation structure extending about 40 kiloparsecs in azimuth at a distance of around 12.7 kiloparsecs from the Galactic center. In some spiral arm regions, vertical displacements can reach approximately 200 parsecs.
The researchers believe these large-scale vertical fluctuations are likely related to "bending waves" triggered by external gravitational disturbances, suggesting that the Milky Way might have experienced more complex interactions during its evolutionary history.
Although the newly discovered structures sound dramatic, they do not have any direct impact on Earth or the solar system. "Humans cannot directly sense these corrugations," Sun said. "Their scales reach thousands or even tens of thousands of light-years, and even if these structures are evolving, such changes would not be directly perceptible on human timescales."
The study focuses on the outer disk of the Milky Way and does not include the region around the solar system. "There is currently no evidence that these structures have any observable influence on Earth's environment," Sun said.
Instead, their significance lies in what they reveal about the past. Like geological layers recording Earth's history, these galactic structures preserve traces of the Milky Way's evolutionary journey, the researchers explained.
Researchers said future studies combining more precise motion measurements and numerical simulations could further reveal the origins of these structures and their role in the long-term evolution of the Milky Way.
。 18日，记者从成都人形机器人创新中心获悉，该中心发布了全球首个复杂语言指令集全自主（无遥控）超长视野机器人任务执行系统，解决了机器人在陌生环境无法自主完成决策规划的难题，让机器人摆脱实验室的“预设摆拍”，走进复杂多变的真实场景中。相关技术已取得发明专利授权。 机器人在真实世界中会遇到观测不完备、环境动力学未知、任务语义歧义、接触状态突变以及执行器误差累积等问题，因此，衡量一个机器人是否“聪明”，不能只看站立、行走或抓取等本体运动指标，更应该进一步考察机器人在长时序任务中状态估计、层级目标推理、策略选择、约束满足和闭环恢复的能力。 成都人形机器人创新中心首发的这套任务执行系统，将世界模型、VLA（视觉—语言—动作）模型等一系列当下流行的技术方案纳入一套统一的框架之中。在演示视频中，搭载该系统的“成都造”超轻量级人形机器人“贡嘎一号”在接收单一复杂指令后，全程自主、稳定执行，依次完成三项子任务。整个过程无遥控、无摆拍，真实展现机器人的全自主作业能力。 据介绍，该执行系统的核心价值不在于堆叠了多少模型，而在于建立了从任务理解到技能选择再到动作执行的完整闭环——解决了真实世界中，机器人没有经过相关场景的数据适配就无法自主完成任务决策规划的难题，让机器人真正具备了在陌生环境中自主完成长时序任务的能力。（记者刘侠）。
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