High-Redshift Black Hole Mass Measurements with Multi-Object Reverberation Mapping

Ohio State University, The, Columbus OH

Investigators

Abstract

Quasi-stellar objects (QSOs) are the cores of distant galaxies whose extreme activity is powered by black holes that may be billions of times the mass of our Sun. The team will study how the optical emission from distant QSOs varies over time. If a QSO's light emission brightens quickly, the surrounding gas will brighten after a time delay that depends on its distance from the black hole. This is the basis of reverberation mapping. The team will measure the time delays for the gas to brighten in a number of QSOs. By modeling the time delay for each QSO, the team will determine the mass of its black hole and the structure of the surrounding gas. They will also develop shortcuts for estimating black hole masses for distant QSOs. Senior team members will train junior members. The public will be informed about the fascinating subject of massive black holes through public talks, social media, and planetarium show content. The team will complete a multi-year campaign of photometric and spectroscopic monitoring of nearly 800 high-redshift QSOs. Their goals are to (1) use reverberation mapping to measure the black hole masses of the QSOs; (2) study the structure of the broad emission-line regions of the QSOs; and (3) develop secondary ways of estimating black hole masses for the population of QSOs at high redshift.