Sharpening our view of Cluster Cosmology

星系团是宇宙中物质分布的极好示踪剂。大量的资源已经投入到编制星团目录中，因为这样的调查可以用来得出重要的宇宙学参数。一种调查技术是使用Sunyaev-Zel'dovich效应（SZE），即星系团内的热气体扭曲了大爆炸产生的光谱。然而，来自单个星系和星系团合并的射电发射可能会使SZE的解释复杂化，从而导致从星系团目录中获得的宇宙学参数的偏差。在无线电频率下拍摄的高分辨率图像可以用来量化这些偏差。研究人员将使用绿岸望远镜（GBT）上的MUSTANG2相机来绘制星团图。这个项目的结果将有助于从过去、现在和未来的星系团调查中获得更准确的结果。在这项工作中，研究人员将维护MUSTANG2，确保它仍然可以被更广泛的天文学界使用。为了帮助培养更多样化的下一代STEM工作者，该团队将与西蒙斯基金会和黑人物理学家协会合作，接待参与MUSTANG2项目的学生。通过参加弗吉尼亚大学举办的女孩探索宇宙（GETU）夏令营，计划向中学生伸出援手。此外，PI将继续在费城地区开展公共宣传活动。在重叠的ACT（阿塔卡马宇宙学望远镜）和eROSITA巡天之间的星团质量的大散射将首先被调查。该团队将(1)在SZE频率下完成对紧凑源的星团的盲调查(2)使用结果来纠正观察样本的质量(3)建立一个模型，用于在统计意义上纠正质量-SZE关系的不同类型的星团中源的可能性有多大，以及(4)对调查之间剩余质量差异的选定星团进行更深入的观察，以找到原因。作为MUSTANG2维护的一部分，该团队将更好地将管道整合到天文台软件基础设施中，进一步促进天文社区对MUSTANG2数据的使用。该奖项反映了美国国家科学基金会的法定使命，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。

Clusters of galaxies are excellent tracers of the matter distribution in the Universe. Significant resources have been put into compiling cluster catalogs, because such surveys can be used to derive important cosmological parameters. One survey technique is to use the Sunyaev-Zel'dovich effect (SZE), which is when hot gas inside galaxy clusters distorts the spectrum of light from the Big Bang. However, radio emission from individual galaxies and cluster mergers can complicate interpretation of the SZE, resulting in sources of bias in cosmological parameters derived from cluster catalogs. High resolution images taken at radio frequencies can be used to quantify these biases. The investigators will use the MUSTANG2 camera on the Green Bank Telescope (GBT) to map clusters. Results from this program will help produce more accurate results from investments in past, current, and future galaxy cluster surveys. During this work, the investigators will maintain MUSTANG2, ensuring it remains available to the wider astronomical community. To help train a more diverse next generation of STEM workers, the team will work with the Simons Foundation and the Society of Black Physicists to host students working on MUSTANG2 projects. Outreach to middle school students is planned by participation in the Girls Exploring The Universe (GETU) summer camp run by the University of Virginia. In addition, the PI will continue public outreach activities in the Philadelphia area. The large scatter in cluster masses between the overlapping ACT (Atacama Cosmology Telescope) and eROSITA surveys will be investigated first. The team will (1) Finish a blind survey of clusters for compact sources at SZE frequencies (2) Use the results to correct the masses of the observed sample (3) Build a model for how likely sources are in different types of clusters that can be used to correct the mass-SZE relationship in a statistical sense and (4) Use deeper observations of selected clusters with remaining discrepant masses between surveys to find the cause. As part of the maintenance of MUSTANG2, the team will better integrate the pipeline into the observatory software infrastructure, further facilitating the use of MUSTANG2 data by the astronomical community.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.