Islands no more: the important mergers of nearby galaxies and their effects

当星系相互作用和碰撞时，星系的形状会发生巨大的变化。在这些碰撞中，两个星系中较小的一个被撕成碎片，并扩散成一个微弱的“恒星晕”，围绕着两个星系中较大的一个。两个星系中较大的一个幸存下来，但可能会因碰撞而伤痕累累。最大的碰撞可能导致新恒星的形成，并可能破坏星系盘。密歇根大学的这个研究小组将把联合收割机的新观测结果与对附近经过充分研究的星系过去经历的碰撞的计算机建模相结合。这一见解将提高我们对星系生长的理解，这些方法将被其他天文学家使用来自Vera C。鲁宾天文台。调查人员将衡量在大学科学入门课程中增加研究经验的积极影响。如果扩大到其他机构，这种方法有可能提高对科学和科学素养的兴趣。在这个项目中，研究人员将在夏威夷的斯巴鲁光学望远镜上使用Hyper Suprime-Cam。 他们将构建恒星晕和卫星系统的深空和广域地图，这些星系的质量与银河系质量相似。 他们计划使用这些新的数据和星系增长模型来开发星系所经历的碰撞的新指标。掌握了这些碰撞的知识，他们可以更好地了解这些碰撞对这五个特定星系的长期影响。重要的是，他们试图证实或反驳过去碰撞与卫星星系数量之间的初步相关性。这些特性可能标志着小尺度宇宙学和星系形成中重要的缺失成分。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Galaxy shapes can change dramatically as galaxies interact and collide with each other. In these collisions, the smaller of the two galaxies is torn to pieces and is spread into a faint ‘stellar halo’ that surrounds the larger of the two galaxies. The larger of the two galaxies survives but can be scarred by the collision. The largest collisions can cause new stars to form and can destroy galaxy disks. This research group at the University of Michigan will combine new observations with computer modeling of the past collisions experienced by nearby, well-studied galaxies. This insight will improve our understanding of galaxy growth, and these methods will be used by other astronomers using huge new datasets from the Vera C. Rubin Observatory. The investigators will measure the positive effects of adding research experiences to large introductory college science courses. If scaled-up to other institutions, this approach has the potential to enhance interest in science and science literacy.During this project, the investigators will use Hyper Suprime-Cam on the Subaru optical telescope in Hawaii. They will construct deep and wide-area maps of the stellar halos and satellite systems of a diverse sample of five galaxies with masses similar to the Milky Way mass. They plan to use these new data and models of galaxy growth to develop new metrics of the collisions experienced by a galaxy. With knowledge of these collisions in hand, they can better understand the long-term effects of these collisions on these five specific galaxies. Importantly, they seek to confirm, or refute, tentative correlations between past collisions and satellite galaxy numbers. These properties may signal important missing ingredients in small-scale cosmology and galaxy formation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.