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”至少包含与银河系一样多的恒星。然而，它们的恒星被压缩成比银河系体积小数千倍的体积。星系形成和演化的理论模型预测，随着宇宙的成熟，这些致密系统应该通过与其他星系的合并和相互作用而成长。覆盖大体积的星系调查，包括致密光谱和高质量成像，非常适合绘制今天的星系如何聚集它们的质量。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，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，星系停止形成恒星后，其大小增长的平均速率主要取决于星系质量。 结合对附近和更遥远（因此更早）宇宙中星系的观察，她证明了大质量星系确实优先通过与质量较小的系统合并而增长。拟议中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，包括数十万个星系的观测距离和宇宙时间时，宇宙是目前年龄的一半。Damjanov博士将探索星系生长的方式如何根据它们在宇宙网中的位置而变化。她将采用基于人工智能的创新技术，梳理大量的星系图像，并构建迄今为止最大的星系样本，这些样本在其光剖面中具有重新合并的签名。研究这些奇特的星系将揭示塑造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节点，它们隐藏着大量的暗物质。这些看不见的物质使来自更远距离的光发生弯曲，使星系图像扭曲（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整个宇宙历史后半段发光和不可见物质的同时演化。