RUI: Advanced Numerical Simulations of Black Hole Accretion

College Of Charleston, Charleston SC

Investigators

Abstract

1. The force of gravity that a black hole exerts is so strong that even light cannot escape. Some black holes form when the core of a star collapses in on itself during a supernova explosion. (A supernova is an exploding star that briefly shines as brightly as the combined light of all the hundreds of billions of stars in an entire galaxy.) Supermassive black holes, with masses millions to billions of times larger than the Sun's may lurk in the centers of most galaxies. A black hole exerts strong tidal forces that can rip apart stars that orbit it too closely. A black hole does not emit radiation itself, but the disruption of a star and infall of the resulting debris both generate considerable energy. Many accreting black hole systems exhibit rapid quasi-periodic oscillations (QPOs). Some produce jets of very high-energy plasma that speed away at velocities close to that of light. The Principal Investigator will use his improved numerical code Cosmos++ to perform simulations of accretion onto black holes. The Intellectual Merit of the proposed research is that it will advance scientists' understanding of black-hole accretion and of the nature of QPOs and properties of jets in such systems. The Broader Impacts include the involvement of students in the research project, as well as the Principal Investigator's participation in various public outreach activities and from the incorporation of his results into classroom lessons. 2. The proposed research will employ the general relativistic magnetohydrodynamics (GRMHD) code Cosmos++ to perform cutting-edge simulations of black hole accretion. The Intellectual Merit of the work is that it will advance astrophysicists' understanding of the differences between viscous and MHD treatments of accretion disks around black holes, of the nature of quasi-periodic oscillations (QPOs) observed in some such systems, and of the orientation of jets in misaligned accretion systems. The Broader Impacts result from the Principal Investigator?s involvement of students in this RUI project, through a variety of public outreach activities, and from the incorporation of his results into his classroom lessons.