CHAMPAIGN, Ill. — Astronomers from the Sloan Digital Sky Survey announced new measurements of the masses of a large sample of supermassive black holes far beyond our universe.
The results, presented at the American Astronomical Society meeting in National Harbor, Maryland, and published in the Astrophysical Journal, represent a major step forward in the ability to measure supermassive black hole masses in large numbers of distant quasars and galaxies.
University of Illinois astronomy professor Yue Shen, postdoctoral researcher David Starkey and graduate student Jennifer Li collaborated on the project with researchers from Pennsylvania State University and the University of Connecticut.
“This is the first time that we have directly measured masses for so many supermassive black holes so far away,” said Catherine Grier, a postdoctoral researcher at Penn State, Illinois physics and astronomy alum and the lead author of the work. “These new measurements, and future measurements like them, will provide vital information for people studying how galaxies grow and evolve throughout cosmic time.”
Using a technique called reverberation mapping, the researchers used the brightness of dust and gas swirling around the black holes – known as quasars – to determine the mass of the black holes. The key to this project lies in its ability to study many quasars at once – the program is currently monitoring 850 quasars simultaneously.
The team’s new, industrial-scale application of the reverberation mapping technique increases the total number of active galaxies with supermassive black holes mass measurements by about two-thirds and pushes the measurements farther back in time to when the universe was only half its current age. But the team isn’t stopping there: It will continue to observe these 850 quasars, and the additional years of data will allow the team to measure black hole masses in even more distant quasars, which have longer time delays that cannot be measured with a single year of data.
“Getting observations of quasars over multiple years is crucial to obtaining good measurements,” said Shen, the principle investigator of the SDSS Reverberation Mapping project. “As we continue our project to monitor more and more quasars for years to come, we will be able to better understand how supermassive black holes grow and evolve.”
The full press release is available from the Sloan Digital Sky Survey.
To reach Yue Shen, call 217-265-4072; shenyue@illinois.edu.
