Collaborative Research: The Radiation Magnetohydrodynamics of Tidal Disruption Events

University Of Wisconsin-Milwaukee, Milwaukee WI

Investigators

Abstract

A tidal disruption event (TDE) is an astrophysical phenomenon that occurs when a star approaches sufficiently close to a supermassive black hole (SMBH) to be pulled apart by the black hole’s tidal force. As this happens, part of the star’s mass is captured in an accretion disk around the black hole (BH), and as this matter falls into the black hole, it accelerates, generating electromagnetic radiation, which can be detected by astronomical telescopes. To better study these events, which can help scientists understand strong gravitational fields, the space around the cores of galaxies, and physics of accretion, a research collaboration between the University of Wisconsin-Milwaukee and the University of Virginia will use numerical simulations to probe the radiation magnetohydrodynamics (the study of emission from highly magnetized plasmas) of TDEs and how the physics is manifest through observational signatures. The investigators will also provide outreach and educational opportunities for students and the community, including presentations at the Manfred Olson Planetarium in Milwaukee, teaching at a summer school in computational science, and mentoring undergraduate students in the VA-NC Alliance and UVA-Spelman exchange summer programs, with the goal of increasing participation of underrepresented groups in STEM research fields. The investigators will use the numerical codes MANGA and Athena++, for which they have made significant algorithmic investments, and which are ideal for numerical simulations of this TDEs. The investigators will realistically model the tidal disruption of stars from initial disruption to fallback and subsequent accretion. In particular, they will determine how magnetic fields and radiation pressure affect the tidal streams from the star’s disruption, drive the evolution of stream-stream collisions, and impact the subsequent accretion onto the black hole, allowing them explore the physics of super-Eddington accretion in TDE events and their observational signatures. This work is crucial for the intepretation of the the large number of events that will be discovered with the current transient surveys and the Vera Rubin Observatory in the near future. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.