Are dwarf galaxy properties a sequence of time or of environment?

我们提出的项目使用新的观测和模拟，以及新的分析方法，以便系统地研究是什么决定了今天矮星系种群的恒星外观和动力学。是否许多矮星系在出生时就具有低自旋，使它们成为与今天典型的恒星形成矮星系不同的物种？还是两者都是从同一个地方开始的，只是外部影响把它们带到了不同的进化道路上？为了解决这个问题，有必要从宇宙学模拟中定义，当今的环境量与星系经历的母晕的历史或它经历的潮汐相互作用的数量最相关。观测到的星系特征可以与这些量相关联，因此可以用一个演变的而不是静态的环境来解释。所要求的博士后将致力于扩大矮星系动力学和空间分辨恒星种群的高质量数据集的数量到各种环境。S/他将系统地研究与各种本地和全球环境量的相关性，根据宇宙学模拟中矮星系种群的时间演化来解释这些相关性，并为现在和过去环境对星系演化的影响建立新的诊断方法。

Our proposed project uses new observations and simulations, as well as new approaches for their analysis, in order to systematically investigate what set the stellar appearance and dynamics of today's dwarf galaxy population. Were many dwarf galaxies already born with low spin, making them a separate species from today's typical star-forming dwarf galaxies? Or did both start out the same and only external influence brought them onto separate paths of evolution? To address this question, it is necessary to define, from cosmological simulations, which present-day environmental quantities correlate best with the history of parent halos that a galaxy went through, or the number of tidal interactions it has experienced. Observational galaxy characteristics can then be related to those quantities and can thus be interpreted in terms of an evolving, not a static, environment. The requested postdoc will work toward expanding the number of high-quality datasets for dwarf galaxy dynamics and spatially resolved stellar populations to various environments. S/he will systematically investigate correlations with various local and global environmental quantities, interpret these based on the time evolution of dwarf galaxy populations in cosmological simulations, and establish new diagnostics for the impact of present and past environment on galaxy evolution.