Many stars form in large clusters containing anywhere from thousands to many millions of objects. Stars in these clusters are born with a broad range of masses. Furthermore, the most massive stars evolve quickly, ending their lives in just a few million years and leaving behind black holes as remnants. The star clusters themselves, however, can continue to live for many billions of years, and indeed the globular clusters seen in many galaxies are thought to contain some of the oldest stars in the Universe. Therefore, many of the star clusters we see today should contain large numbers of black holes formed a long time ago. This research will use state-of-the-art supercomputer simulations to study the formation and evolution of these black holes in a variety of star cluster environments. It will also leverage innovative hybrid computational techniques, including General-Purpose computing on Graphics Processing Units (GPGPU).
The study of black hole formation and evolution is important in many areas of physics and astronomy, including galaxy formation and cosmology, the study of quasars and other active galactic nuclei, general relativity and gravitational wave astronomy. The stellar dynamics supercomputer codes to be developed for this project are general tools, which will be useful for studying many other problems involving dense star clusters with or without massive black holes. The planned research activities will involve the training of undergraduate students at Northwestern University, and will likely include students from under-represented minorities. Graduate students will also receive training and mentoring. Outreach activities are also planned that will take advantage of Dearborn Observatory on the Northwestern campus in Evanston, as well as the resources of the nearby Adler Planetarium and Astronomy Museum in Chicago.
