Astronomy and Astrophysics

天文学和天体物理学

• 批准号: CRC-2021-00376
• 负责人: Damjanov, Ivana
• 金额: $ 5.46万
• 依托单位: Saint Mary's University
• 依托单位国家: 加拿大
• 项目类别: Canada Research Chairs
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743940
• 关键词: Astronomy; Astrophysics

The most massive galaxies of the early universe are different from their descendants observed in our galactic neighbourhood. When they stop forming stars, these distant "island universes" contain at least as many stars as the Milky Way. However, their stars are packed into volumes thousands of times smaller than the volume of the Milky Way. Theoretical models of galaxy formation and evolution predict that these dense systems should grow through mergers and interactions with other galaxies as the universe matures.Galaxy surveys that cover large volumes and include both dense spectroscopy and high-quality imaging are uniquely suited to map out how today's galaxies assemble their mass. As CRC in Astronomy and Astrophysics Dr. Damjanov uses this synergy to probe the relations between galaxy size growth, the changes in their stellar and (invisible) dark matter content, and their position within the web that the invisible cosmic material weaves throughout the universe. She has discovered that the average rate at which galaxies grow in size after they cease forming stars depends critically on galaxy mass. Combining the observations of galaxies in the nearby and in more distant (and thus earlier) universe, she has demonstrated that massive galaxies indeed grow preferentially through mergers with less massive systems. Proposed research will take current spectroscopic surveys with high-resolution imaging to the next level by including hundreds of thousands of galaxies observed to distances and cosmic times when the universe was half of its current age. Dr. Damjanov will probe how the way galaxies grow changes depending on their location with respect to the cosmic web. She will employ innovative techniques based on artificial intelligence to comb through vast volumes of galaxy images and construct the largest to-date samples of galaxies with signatures of resent mergers in their light profiles. Studying these peculiar galaxies will unveil the types of gravitational interactions that shape them. Massive clusters of galaxies that illuminate knots of the cosmic web harbour large amounts of dark matter. This invisible mass bends the light coming from larger distances, distorting (and even multiplying) galaxy images into arc-like shapes. Dr. Damjanov will study these signatures in galaxy clusters from her survey to trace, in the most direct way possible, simultaneous evolution of luminous and invisible matter throughout the second half of cosmic history.

早期宇宙中最大质量的星系与我们在银河系附近观察到的它们的后代不同。当它们停止形成恒星时，这些遥远的“岛屿宇宙”包含的恒星数量至少与银河系一样多。然而，它们的恒星组成的体积比银河系的体积小几千倍。星系形成和演化的理论模型预测，随着宇宙的成熟，这些致密系统应该会通过与其他星系的合并和相互作用而增长。覆盖大体积、包括密集光谱和高质量成像的星系调查非常适合绘制出今天的星系如何聚集它们的质量。正如CRC在天文学和天体物理学中所做的那样，Damjanov博士利用这种协同效应来探索星系大小增长、其恒星和(不可见)暗物质含量的变化，以及它们在不可见宇宙物质交织整个宇宙的网络中的位置之间的关系。她发现，星系停止形成恒星后，其大小增长的平均速度主要取决于星系的质量。结合对附近和更远(因此更早)宇宙中星系的观察，她证明了大质量星系确实通过与质量较小的系统合并而优先增长。拟议中的研究将把目前具有高分辨率成像的光谱调查提升到一个新的水平，包括在宇宙年龄的一半时观察到的数十万个遥远和宇宙时间的星系。达米亚诺夫博士将探索星系的生长方式是如何根据它们在宇宙网络中的位置而变化的。她将使用基于人工智能的创新技术来梳理大量的星系图像，并构建迄今为止最大的星系样本，在它们的光线轮廓中带有重新合并的签名。研究这些特殊的星系将揭示塑造它们的引力相互作用的类型。照亮宇宙网结的大质量星系团蕴藏着大量的暗物质。这种看不见的质量使来自更远距离的光线发生弯曲，将星系图像扭曲(甚至倍增)成弧形。达米亚诺夫博士将从她的调查中研究星系团中的这些信号，以尽可能直接的方式，在宇宙历史的后半部分追踪发光物质和不可见物质的同时演化。