NSF Award
2107870
The primary goal of this project is to map the dark matter structures in a large sample of nearby galaxy clusters using data from the Dark Energy Camera at the Cerro Tololo Inter-American Observatory. The investigators will study how dark matter forms structures of various sizes in the clusters. The images will provide the nearby comparison sample to the more distant clusters that will be observed with the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope. The project includes programs for student research at the high school, undergraduate, and graduate levels. The outreach programs will take place in both the Providence Public School system and the south-east Ohio Appalachian region. <br/><br/>The distribution of mass in a complete sample of clusters will be measured via weak lensing, measuring the distortion of the observed shape of background galaxies due to the curvature of space-time around the matter in the cluster. This distribution of mass will be mapped and compared to the distribution of cluster galaxies and X-ray emitting gas. Two-dimensional maps of the mass will be reconstructed with high enough resolution to identify individual concentrations within the cluster (“substructures”). In addition, the effect of these substructures on the estimates of the total mass of the clusters will be measured. This will determine the mass calibration biases in upcoming cluster surveys. These observations are similar in depth to the upcoming observations from the Vera Rubin Observatory, enabling a transient survey in and behind nearby clusters with the first-year of data from the Legacy Survey of Space and Time (LSST). The project will make public releases of deep optical images, catalogs, and maps of the dark matter yearly. These releases are designed to help other researchers become familiar with the data format and quality of the future LSST datasets. The investigators will recruit students into science using proven outreach programs, while partnering with the staff at Ladd Observatory, the Brown Science Prep program, and the Providence Children’s Museum. Through these programs, the investigators will introduce fundamental aspects of astronomy to the large percentage of underprivileged and minority students in the Providence public school system. A similar outreach program will be implemented in the historically under-served and poverty-stricken south-east Ohio Appalachian region.<br/><br/>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.
