Unveiling the low-surface-brightness Universe with new deep-wide surveys: the role of mergers in driving galaxy evolution

合并是星系演化的主要驱动力，它触发恒星形成幕，建造黑洞，并引发形态变化。由于低质量星系的数量超过了它们的大质量星系，星系的组装主要是通过不同质量比的合并(“小合并”)进行的。然而，尽管很明显是基本的，但微小的合并实际上仍然没有被探索，因为它们产生的低地表亮度的潮汐特征在今天的调查中是看不到的。对合并(以及星系演化)的完整理解需要探索低表面亮度的宇宙，例如使用LSST这样的望远镜。虽然LSST和其他设施将开启低表面亮度天文学的新时代，但需要开发探测/表征低表面亮度潮汐特征所需的算法。这名学生将使用最先进的宇宙学模拟(例如Horizon-AGN)来创建模拟星系图像，在这些图像上构建/训练算法，在现有的前体数据集上测试它们，并为LSST、Euclid、DES等设施建造低表面亮度管道。他/她将坐在由赫特福德郡领导的合作网络的中心，在普林斯顿、牛津和巴黎天体物理研究所设有节点。学生将获得关键理论和观测技术方面的专业知识，并撰写关于低表面亮度科学和合并在星系演化中的作用的基准论文。

Merging is the principal driver of galaxy evolution, triggering star-formation episodes, building black holes and inducing morphological transformations. Since low-mass galaxies outnumber their massive counterparts, galaxy assembly proceeds primarily via mergers with unequal mass ratios ('minor mergers'). However, while clearly fundamental, minor merging remains virtually unexplored, as the low-surface-brightness tidal features they produce are invisible in today's surveys. A complete understanding of merging (and therefore galaxy evolution) requires exploration of the low-surface-brightness Universe, e.g. using a telescope like LSST. While LSST and other facilities will usher in a new era of low-surface-brightness astronomy, the algorithms required to detect/characterize low-surface-brightness tidal features need to be developed. The student will use state-of-the-art cosmological simulations (e.g. Horizon-AGN) to create mock galaxy images, build/train algorithms on these images, test them on available precursor datasets and build low-surface-brightness pipelines for facilities like LSST, EUCLID, DES etc. He/she will sit at the centre of a collaborative network that is led by Hertfordshire, with nodes at Princeton, Oxford and the Institut d'Astrophysique de Paris. The student will gain expertise in key theoretical and observational techniques and write benchmark papers on low-surface-brightness science and the role of mergers in galaxy evolution.