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在我们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，它们的恒星体积比银河系小数千倍。星系形成和演化的理论模型预测，随着宇宙的成熟，这些致密系统应该通过与其他星系的合并和相互作用而成长。覆盖大体积并包括致密光谱和高质量成像的星系调查特别适合绘制当今星系如何聚集其质量。作为天文学和天体物理学领域的 CRC，达姆贾诺夫博士利用这种协同作用来探索星系尺寸增长、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在整个宇宙中编织的网络中的位置之间的关系。她发现，星系停止形成恒星后尺寸增长的平均速度很大程度上取决于星系质量。 结合对附近和更遥远（因此更早）宇宙中星系的观测，她证明了大质量星系确实会通过与较小质量系统的合并来优先生长。拟议的研究将把当前的高分辨率成像光谱调查提升到一个新的水平，包括在宇宙年龄仅为当前年龄一半时观测到的数十万个星系的距离和宇宙时间。达姆贾诺夫博士将探讨星系生长的方式如何根据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星系图像，并构建迄今为止最大的星系样本，并在其光剖面中显示重新合并的特征。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。照亮宇宙网结的巨大星系团蕴藏着大量暗物质。这种看不见的质量使来自更远距离的光线弯曲，将星系图像扭曲（甚至倍增）成弧状形状。达姆贾诺夫博士将研究她的调查中星系团中的这些特征，以尽可能最直接的方式追踪整个宇宙历史后半段发光物质和不可见物质的同时演化。