Galaxies in the local universe are most commonly found in groups and are thought to be "pre-processed" in this environment before being consumed by clusters. Yet we know very little about the gastrophysics of these systems, how they evolve and how this environment is connected to the quenching of star-forming galaxies. In particular, the role of intragroup gas has been challenging to uncover due to observational constraints and the limitations of radio telescopes to date. Sensitive, interferometric \HI\ observations of galaxy groups, combined with multiwavelength tracers of stellar mass, star formation and shocks, is necessary to examine the physical processes transforming galaxies from star-forming to quenched. These laboratories may be key to understanding the dominant mechanisms driving galaxy evolution. MeerKAT uniquely combines a large field of view, column density sensitivity, and excellent UV coverage on short baselines ensuring sensitivity to diffuse gas. This design makes it a compelling instrument for the study of intragroup and circumgroup gas, quenching in galaxy groups, and for tracing evolutionary pathways within the group environment.
翻译:本地宇宙中的星系最常见的是星系群,据认为,在被星群消耗之前,在这种环境中是“预处理”的。然而,我们对这些星系的气形物理学、其演变方式以及这种环境如何与恒星成形星系的挤压联系起来知之甚少。特别是,由于观测限制和射电望远镜迄今为止的局限性,集团内气体的作用一直难以发现。对星系群的敏感、相互测量和HI\观察,加上星团、恒星形成和冲击等多波长的跟踪器,对于审查从恒星成形到被挤压的星系的物理过程是必要的。这些实验室可能是了解驱动星系进化的主导机制的关键。MeerKAT独家将一个大视野、柱密度敏感度和极好的紫外线覆盖结合起来,以确保对扩散气体的敏感度。这种设计使星系内部和环组气体的研究、星系组的挤压和跟踪群内进化路径成为令人信服的工具。