Collaborative Research: Reverberation Mapping with Multi-Object Spectroscopy - from Sloan Digital Sky Survey Reverberation Mapping to the Black Hole Mapper

This project will study the flicker of light from supermassive black holes that linger at the center of most of the big galaxies in the universe. These supermassive black holes weigh more than a million (up to about ten billion) times the mass of the Sun, and the glowing radiation from materials being “fed” into these black holes can outshine the star light from the entire galaxy, allowing these black holes to be observed in the very distant regions of the universe. In this project, astronomers will measure the variations of radiation from these supermassive black holes and how the materials immediately surrounding the black hole “echo” this variability. This measured echo allows astronomers to infer the mass of these monster black holes that are actively growing, and, in turn, help them understand how supermassive black holes form and evolve across cosmic history. In the area of Broader Impacts, the PIs plan to incorporate their research into strong educational and outreach programs at each of their institutions. In particular, these programs include a summer camp for high school girls, centered on data analysis, a black-hole workshop for middle schools, and a new summer bridge program for physics undergraduates from non-traditional backgrounds. These programs will encourage the participation of groups traditionally underrepresented in STEM fields. Supermassive black holes are ubiquitous at the center of massive galaxies in the universe. When they are actively accreting matter to build up their mass, they can produce immense radiation that often outshines the entire galaxy in which these massive black holes reside. This radiation from active supermassive black holes is not constant, but flickers at levels that are measurable with modern astronomical facilities. This project will measure the flicker from thousands of such active supermassive black holes over a five-year period, and the “echoes” from gas clouds immediately surrounding the black hole. These echo measurements will infer the spatial extent of these gas clouds in the vicinity of the black hole, and enable the measurement of the black hole mass. This project will use this technique to measure the masses of active supermassive black holes on an unprecedented industrial scale, most of which are billions of light years away, to understand the cosmic evolution of supermassive black holes and their relationships with their host galaxies. 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.