Supermassive Black Holes – With Guest Dr. Kelly Holley-Bockelmann (Part 3)

February 18, 2013

John P. Millis, Ph.D. and Jedidiah Becker for – Your Universe Online

Only a couple decades ago, the mere idea of supermassive black holes – those that are millions or billions of times more massive than our sun – seemed unthinkable to most astronomers. Now, however, we believe that these enormous objects lie at the center of nearly every galaxy in the Universe.

But simply knowing that these black holes exist is only the tip of the iceberg, and one of the most intriguing research questions in this field today remains, where do supermassive black holes come from?

Since normal, stellar-mass black holes are created by the collapse of large main sequence stars in brilliant supernovae, it seems logical that supermassive black holes might be created in a similar manner during the collapse of supermassive stars. However, both our theoretical understanding of physics as well as observational data indicate that this simply isn’t the case; supermassive stars don’t appear in our Universe.

Another puzzling aspect of supermassive black holes is the manner in which they seem to interact with their host galaxies. For instance, observational data tells us that the size of a supermassive black hole appears to be directly related to the size of its host galaxy – that is, larger galaxies host larger supermassive black holes, and smaller galaxies host smaller ones. Yet it remains unclear as to why this should be the case, and researchers are still trying to figure out the mechanism behind how the outer reaches of a galaxy can be influenced at all by the black hole at its core.

To explore these questions, we spoke once again with Vanderbilt University theoretical physicist and black hole expert, Kelly Holley-Bockelman. One of Professor Holley-Bockelman’s specialty fields involves using supercomputers to create simulations of evolving galaxies in an attempt to understand how these supermassive black holes form and grow over time.

And if you missed parts one or two of this series, “How Stars Die and Black Holes Form” or “Facts About Black Holes: Separating Myth From Reality,” be sure to listen to them first.


Kelly Holley-Bockelmann has been an Assistant Professor of Astronomy at Vanderbilt University since 2007. She received her B.S. in Physics at Montana State University and her PhD in Astronomy in 1999 at the University of Michigan. After her PhD, she did postdoctoral work at Case Western Reserve University and the University of Massachusetts. In 2004, she joined the Center for Gravitational Wave Physics at The Pennsylvania State University, where she became a big fan of gravitational waves and attended many talks on loop quantum gravity that left her scratching her head.

Her main interests are in computational galaxy dynamics, black holes of all sorts, and gravitational waves. She is a recipient of a Faculty Early Career Development (CAREER) award from the National Science Foundation and her work also been supported by the NASA. Dr. Holley-Bockelmann’s research on growing supermassive black holes and rogue black holes have both been featured in many online and print media outlets, though she still gets a bit nervous talking to the press.

As a first-generation college graduate within a family that sometimes lived below the poverty level, Dr. Holley-Bockelmann has a deep interest in broadening the participation of women, minorities, and first-generation college students in science. She is a part of the Fisk-to-Vanderbilt Master’s-to-PhD Bridge Program, which is designed to mentor a diverse cohort of graduate students to develop the skills needed to succeed as a scientist.