Collaborative Research: Exploring the Formation and Growth of Supermassive Black Holes through Variability and Transients

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Supermassive black holes can be millions to billions of times the mass of our Sun and are found in the centers of most large galaxies. However, the formation of these supermassive black holes and the methods by which they grow remain uncertain. While astronomers cannot observe the black holes directly, light from gas or stars falling onto the black holes will produce bright disks of accretion that can be. In this program, the PIs will study time-variable signatures from these systems to provide unique constraints on the properties and environments of black holes in the centers of galaxies. This work will address fundamental questions about formation and evolution of supermassive black holes. The investigators will also develop a set of inquiry-based educational materials for high school students. These materials will convey excitement about supermassive black holes while addressing common misconceptions about extreme gravity. The activities will map to the key scientific practices identified by the Next-generation State Standards used by both Illinois and Washington and provide students an opportunity to engage in exploration and discussion. Supermassive black holes (SMBHs) are ubiquitous in the centers of massive galaxies, yet the formation of SMBH progenitors and their routes of growth remain unclear. The properties of SMBHs can be revealed by the accretion of gas or tidally-disrupted stars. Variable or transient emission from these phenomena provide constraints on the masses, accretion disk properties, and small-scale environments of these SMBHs. The study will (1) identify intermediate mass black holes in order to understand possible routes for SMBH formation, and (2) constrain the environments of active and quiescent SMBHs to understand how SMBHs grow and how they co-evolve with their host galaxies. This work will use observations from the Young Supernova Experiment -- a repeat imaging survey using the Pan-STARRS telescopes to image 1500 square degrees of sky in four bands with a three day cadence. They will search for active and quiescent SMBHs in low-mass galaxies through variability and tidal disruption events, respectively. They will identify and characterize changing-state AGN, use continuum reverberation mapping to study accretion disk properties, and study the broader population of tidal disruption events observed by the Young Supernova Experiment. This project will also study the environments and host galaxy properties of active and quiescent SMBHs as they grow and evolve, which will inform studies of galaxy--SMBH co-evolution and provide predictions for future work with the Vera C. Rubin Observatory. 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.