A unified approach to the study of dark matter and baryons in the large scale structure of the Universe

研究宇宙大尺度结构中暗物质和重子的统一方法

• 批准号: RGPIN-2014-04645
• 负责人: VanWaerbeke, Ludovic
• 金额: $ 3.06万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=667555
• 关键词: unified; approach; study; dark; matter

The study of the universe is stumbling upon two mysteries : it is made for 5% of normal matter, 20% of an unknown type of matter, dark matter, and for 75% of a puzzling form of energy, dark energy. A worldwide quest is underway to probe, map and explain those dark components. In the past ten years, a dozen of international teams organized mega surveys involving the largest ground based telescopes and state of the art satellites, and developed ground breaking computing techniques to analyse thousands of terabytes of data.**Gravitational lensing is the tool of choice to reveal the presence of dark matter. According the Einstein's general theory of relativity, light from distant galaxies is distorted by massive astronomical bodies present between the source and the observer. This property can be used to weigh and map matter that cannot be detected by any other means. Fifteen years ago, L. Van Waerbeke was among the pioneers who laid the theoretical and observational foundations of this new field of research. By statistically analyzing the distorted shapes of millions of background galaxies, he performed the first detection of gravitational lensing by a large scale structure. Today, gravitational lensing is leading the science in several international satellite projects like Wide Field Infrared Survey Telescope in the US and Euclid in Europe. For the past five years, L. Van Waerbeke has led an international team, CFHTLenS, who brought gravitational lensing to a new level of precision and reliability. Analyzing 4 TB of data, CFHTLenS provided the first large scale map of dark matter, which in turn provides clues about how galaxies formed and how dark matter evolved in their halos. In 2013 alone, CFHTLens papers received more than 190 citations. The team made their highly processed data publicly available at the Canada Astronomy Data Centre and received 200,000 hits in the first twelve months.**For the past twenty years, the Big Bang theory has been confirmed by a large body of evidence, like the famous observations of the cosmic microwave background radiation (CMB), but some gaps persist. Three and a half billion years into the history of the universe, 50% of protons and electrons became invisible to astronomers; for the past fifteen years, these "missing baryons" have been searched by X-ray and microwave satellites. In 2013, L. Van Waerbeke showed that gravitational lensing combined with CMB observations can detect the presence of missing baryons, opening the door to a new field of research that could measure their temperature and density, explore how they are recycled in stars, and bring a new confirmation of the Big Bang theory, and shed a new light on structure formation. Gravitational lensing data could also be cross correlated (GLx) with other mega surveys to probe the physics of baryons.**In the five coming years, L Van Waerbeke will train a team of two postdoctoral fellows and four graduate students, and at least five undergraduate students, to develop new computing tools and simulations in order to become the leading team in GLx. The two known types of matter, baryons and dark matter, are intertwined, and L. Van Waerbeke believe that it is time to build models combining them together. In the coming decade, ever larger surveys will be undertaken, covering the entire sky. Dark matter and baryons in all possible stated will be mapped. L. Van Waerbeke wants to lay the theoretical and practical foundations to efficiently analyze this massive influx of data. Personnel trained in his team will export this expertise worldwide. In the near future, he expects this field of research to have far reaching applications, like measuring the mass of the elusive neutrino particles and refining Einstein's theory of gravity.

对宇宙的研究正陷入两个谜团：它是由5%的正常物质，20%的未知物质暗物质和75%的令人费解的能量形式暗能量组成的。一项全球范围的探索正在进行中，以探测、绘制和解释这些黑暗的成分。在过去的十年里，十几个国际团队组织了大型调查，涉及最大的地面望远镜和最先进的卫星，并开发了突破性的计算技术来分析数千TB的数据。引力透镜是揭示暗物质存在的首选工具。根据爱因斯坦的广义相对论，来自遥远星系的光被存在于光源和观察者之间的大质量天体扭曲。这种特性可以用来称量和映射任何其他方法都无法检测到的物质。15年前，L。货车Waerbeke是其中的先驱谁奠定了理论和观测基础，这一新的研究领域。通过统计分析数百万个背景星系的扭曲形状，他首次通过大尺度结构探测到引力透镜。今天，引力透镜在几个国际卫星项目中处于领先地位，如美国的宽视场红外巡天望远镜和欧洲的欧几里得。在过去的五年里，L。货车瓦尔贝克领导了一个国际团队CFHTLenS，他们将引力透镜的精度和可靠性提高到了一个新的水平。CFHTLenS分析了4 TB的数据，提供了第一张大规模的暗物质地图，这反过来又提供了关于星系如何形成以及暗物质如何在晕中演化的线索。仅在2013年，CFHTLens的论文就被引用了190多次。该团队在加拿大天文数据中心公开了他们高度处理的数据，并在前12个月内收到了200，000次点击。在过去的20年里，大爆炸理论已经被大量的证据所证实，比如著名的宇宙微波背景辐射（CMB）观测，但仍然存在一些差距。在宇宙形成的35亿年里，50%的质子和电子对天文学家来说是不可见的;在过去的15年里，这些“失踪的重子”一直在被X射线和微波卫星搜索。2013年，L.货车Waerbeke表明，引力透镜与CMB观测相结合可以检测到缺失重子的存在，为一个新的研究领域打开了大门，可以测量它们的温度和密度，探索它们如何在恒星中循环，并为大爆炸理论带来新的确认，并为结构形成提供新的见解。引力透镜数据也可以与其他大型调查交叉相关（GLx），以探索重子的物理学。在未来的五年里，L货车Waerbeke将培养一个由两名博士后研究员和四名研究生以及至少五名本科生组成的团队，以开发新的计算工具和模拟，从而成为GLx的领先团队。两种已知的物质类型，重子和暗物质，是交织在一起的。货车Waerbeke认为，现在是时候建立模型结合起来。在未来十年，将进行更大规模的调查，覆盖整个天空。暗物质和重子在所有可能的状态将被映射。L.货车Waerbeke希望为有效分析这些大量涌入的数据奠定理论和实践基础。在他的团队中受过培训的人员将向全世界输出这种专门知识。在不久的将来，他预计这一研究领域将有深远的应用，如测量难以捉摸的中微子粒子的质量和完善爱因斯坦的引力理论。