Understanding Black Holes in Galaxies

Research on galaxy mergers and the cosmic evolution of the relations between the central black hole and its host galaxy.

Dr. Francisco Müller-Sánchez, assistant professor in the Department of Physics and Materials Science, has been awarded over $250,000 in grants from the National Aeronautics and Space Administration (NASA) and the James Webb Space Telescope to continue his research on galaxy formation and evolution.

Müller-Sánchez’s research interest ranges from the physical properties of active galactic nuclei (AGN) and nuclear star clusters to the role of supermassive black holes (SMBHs) in galaxy evolution. There may be more monstrous black holes in the universe than previously thought. Muller-Sanchez states, “Continuing to focus on galaxy mergers and the cosmic evolution of the relations between the central black hole and its host galaxy is very important.” Working on physics and astronomy to better understand that all galaxies in the universe have a supermassive black hole at the center. Some recent results suggest that black holes strongly influence the physical processes occurring in galaxies.

Müller-Sánchez studies the regions around SMBHs with a sufficient spatial resolution to directly observe how SMBHs are fueled, how they influence their host galaxies, and under what circumstances SMBH pairs make it to the detectable gravitational-wave regime. Prior, students flew to the Stratospheric Observatory for Infrared Astronomy (SOFIA). The students performed astronomical observations of accreting supermassive black holes, one of the main areas of Muller-Sanchez’s research.

SOFIA is a 2.7-meter telescope carried aboard a Boeing 747SP aircraft. The NASA Armstrong Flight Research Center in Palmdale, California, conducts flight operations. The telescope is in an open cavity in the rear section of the aircraft, with a view out of the port side. The observatory provides imaging and spectroscopic capabilities in the infrared part of the electromagnetic spectrum, making SOFIA one of the premier infrared astronomical facilities. The observations obtained by the students characterize the nature of dual supermassive black holes, which are rare pairs in galaxy mergers and ideal targets for testing unification models of galaxy evolution.

Müller-Sánchez and his student researched the masses of several enormous black holes and those of the host galaxies bulged and are finding a proportional relationship between them. This indicates the formation of the massive black hole and its galaxy are closely related. The growth of these black holes releases vast amounts of energy that powers quasars and other weaker active galactic nuclei. If absorbed by the host galaxy, a tiny fraction of this energy could halt star formation by heating and ejecting ambient gas.

One result of his research, his students are gaining critical life skills that can be transferable and applicable to a future career. The students find it valuable to identify skills used in their research. New graduates need more required skills and must call upon transferable skills developed during their academic and research experience. Such skills include but are not limited to programming languages, data analysis, and applying theoretical models to actual data to interpret phenomena that occur in the universe.

Müller-Sánchez received his Ph.D. in Physics and Astronomy from the Ludwig Maximillian University in Munich (LMU), working at the Max-Plank Institute for Extraterrestrial Physics (MPE) in Garching, Germany. He also has spent three years as a postdoctoral fellow at the Instituto de Astrofisica de Canarias (IAC) in Spain, two years as a postdoctoral fellow at the University of California Los Angeles (UCLA), and five years as a research associate at the University of Colorado, Boulder, before accepting his current position at the University of Memphis.

For information about galaxy formation and evolution, contact Müller-Sánchez at f.muller.sanchez@memphis.edu, or call 901-678-4733.