Collaborative Research: CDS&E: Evolution of the High Redshift Galaxy and AGN Populations

宇宙结构形成的冷暗物质（CDM）范式已经取得了许多成功，从预测宇宙微波背景波动的光谱到解释星系聚集。但CDM理论仍然与观测到的星系性质不一致，在这些尺度上，气体冷却、恒星形成和反馈等重子物理是重要的。由于需要巨大的动态范围和分辨率，在宇宙学背景下对这些过程进行建模是极其困难的，并且需要最先进的计算硬件以及新的计算技术和算法。提议的团队已经开发了平滑粒子流体动力学（SPH）代码，以解决星系尺度上的这些过程，并计划将他们的算法适应新的架构，以便将它们扩展到宇宙体积。除了将他们的恒星形成和反馈算法从传统的消息传递接口（MPI）代码转移到并行语言（CHARM++）之外，他们还打算实现更快的算法，以实现所需的动态范围，并充分利用Blue Waters系统上数十万个处理核心。结果将由创建模拟观测的并行管道进行处理。模拟还将用于一个针对代表性不足的科学预科学生的项目，向他们介绍在天体物理学中使用计算机模拟，并鼓励他们选择技术型专业。

The Cold Dark Matter (CDM) paradigm for the formation of structure in the universe has had many successes, from predicting the spectrum of fluctuations in the Cosmic Microwave Background to explaining the clustering of galaxies. But CDM theory is still at odds with the observed properties of galaxies on scales where the baryonic physics of gas cooling, star formation and feedback are important. Modeling these processes in the cosmological context is extremely difficult owing to the immense dynamic range and resolution needed, and requires the most advanced computational hardware available as well as new computing techniques and algorithms. The proposing team has developed smooth-particle hydrodynamics (SPH) codes addressing these processes at the galaxy scale, and plans to adapt their algorithms to new architectures in order extend them to cosmological volumes. In addition to moving their star formation and feedback algorithms from legacy message-passing interface (MPI) codes to a parallel language (CHARM++), they intend to implement faster algorithms that can achieve the needed dynamic range and take full advantage of the hundreds of thousands of processing cores on the Blue Waters system. The results will be processed by a parallel pipeline that creates simulated observations. The simulations will also be used in a program targeting science pre-majors from under-represented groups, introducing them to the use of computer simulations in astrophysics and encouraging them toward technically oriented majors.