The First Multi-Object Reverberation Mapping Survey: Transforming Our Knowledge of Distant Black Hole Demographics

A longstanding problem in astrophysics is to understand how galaxies form and develop throughout their lifetimes. Such understanding is necessary to uncover how our Universe evolved and to gain insight into the origin of our own Milky Way Galaxy. One important aspect of understanding galaxy formation and evolution is to study supermassive black holes (SMBHs) at the centers of galaxies and active galactic nuclei (AGNs). The investigators in this project will use a pioneering new data set acquired through the Sloan Digital Sky Survey multi-object reverberation mapping project (SDSS-RM) to transform our knowledge of black hole demographics and the physics of AGNs across the observable Universe. This project will yield the first set of reliable reverberation-mapping (RM) black hole masses (MBH) that includes targets at very large distances from Earth (with redshifts z > 0.3); these RM results will allow us to investigate whether SMBH growth leads or lags galaxy star formation and to more accurately characterize the physics regulating the growth and feedback of AGNs.

In addition, the investigators will use SDSS-RM data to design and execute a summer research program for high school students participating in Penn State's Summer Research Experience in the Eberly College of Science. This program is operated in collaboration with Penn State's Upward Bound Math and Science center and targets students from underserved school districts in Pennsylvania. The investigators will provide low-income students with the opportunity to interact with scientists and to learn basic astronomy data analysis. This program will provide mentoring experience for postdocs, who will supervise the Penn State student leading the workshop. This Penn State student will in turn gain experience by mentoring the high school students participating in the program. Both faculty collaborators will mentor the participating postdocs; this will give them the opportunity to teach, strategically plan for future career goals, and become leaders in large-scale time-domain spectroscopic research.

The investigators will use the SDSS-RM data to accomplish the following: (1) Measure black hole masses for 100 quasars, tripling the existing sample size and expanding it to cover the broad range in quasar parameter space missed by previous RM surveys (in redshift, luminosity, and emission-line properties), (2) Employ these black hole masses to improve substantially our understanding of black-hole/galaxy scaling relations used to characterize supermassive black hole (SMBH) mass demographics, and (3) Characterize the structure and physics of the broad line-emitting region using the responses of various emission lines and velocity-resolved reverberation methods. Unlike previous work, which was limited by highly uncertain MBH values that resulted in largely unconstrained estimates of any possible evolution of SMBH-galaxy relationships, the SDSS-RM data set will distinguish between causal or coincidental coevolution by enabling the first study of evolution in the intrinsic scatter of the MBH-host galaxy correlations. The response of the broad line region across various emission lines will provide crucial insights regarding the physics governing and regulating AGN and SMBH/galaxy evolution.