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.

早期宇宙中质量最大的星系与我们在银河系附近观测到的后代不同。当它们停止形成恒星时，这些遥远的“岛屿宇宙”至少包含与银河系一样多的恒星。然而，它们的恒星被包裹在比银河系体积小几千倍的体积里。星系形成和演化的理论模型预测，随着宇宙的成熟，这些密集的系统应该通过合并和与其他星系的相互作用而增长。覆盖大范围的星系调查，包括密集的光谱和高质量的成像，是唯一适合绘制当今星系如何聚集其质量的地图。作为天文学和天体物理学的CRC， Damjanov博士利用这种协同作用来探索星系大小增长之间的关系，它们的恒星和（不可见的）暗物质含量的变化，以及它们在整个宇宙中不可见的宇宙物质编织的网络中的位置。她发现，星系在停止形成恒星后，其大小增长的平均速度，在很大程度上取决于星系的质量。结合对附近和更远（因此更早）宇宙中的星系的观察，她证明了大质量星系确实优先通过与较小质量系统的合并而增长。拟议的研究将把目前的光谱调查与高分辨率成像提升到一个新的水平，包括成千上万的星系观察到的距离和宇宙时间，当宇宙是目前年龄的一半。Damjanov博士将探索星系的生长方式如何随着它们相对于宇宙网的位置而变化。她将采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，在它们的光剖面中具有最近合并的特征。研究这些奇特的星系将揭示形成它们的引力相互作用的类型。巨大的星系团照亮了宇宙网的结，其中蕴藏着大量的暗物质。这个看不见的物质使来自更远的光线弯曲，将星系图像扭曲（甚至倍增）成弧形。Damjanov博士将从她的调查中研究星系团中的这些特征，以尽可能直接的方式追踪在整个宇宙历史的后半段，发光和不可见物质的同时演化。