Fellow 2018-19

Yue Shen


Artist's impression of an Active Galactic Nucleus
Copyright: ESA/NASA, the AVO project and Paolo Padovani

Supermassive Black Hole Physics and Evolution with Time-Domain Exploration

Accurately measured masses of supermassive black holes (SMBHs) in distant Active Galactic Nuclei (AGN) are cornerstones for understanding the cosmic assembly of SMBHs and their co-evolution with massive galaxies. BH mass estimates are available for a small sample of nearby AGN using a technique called reverberation mapping (RM). The small sample size and the fact that the current sample does not probe the full parameter space of the distant AGN population impose severe limitations in the studies of the cosmic growth of SMBHs and their co-evolution with host galaxies. The only way to improve the situation is by expanding substantially the sample of AGN with RM measurements, to improve the statistics and to cover AGN parameter space uniformly.

The proposed project aims to advance this field significantly using the first major multi-object RM program (SDSS-RM), developed and led by Professor Shen, that performs efficient RM for a large, uniformly-selected AGN sample that covers a wide range of redshifts and physical properties. The key objectives include the measurements of broadline region (BLR) sizes and the BH masses of these distant AGN, and the investigation of the redshift evolution of the correlations between BH mass and host galaxy properties. Overall, the scientific results expected from this project will significantly advance the field of AGN and galaxy formation, and will have tremendous value to a diverse research area and a broader astronomical community. Improved methods of BH mass estimation in distant AGN will benefit essentially all studies on SMBHs, such as the demographics and evolution of AGN, the physical processes of BH accretion and feedback, and the co-evolution of SMBHs and galaxies.