Investigating Truncated Disk Simulations for Signs of Quasi Periodic Oscillations

Student: Filippo Savoia

Major: Astrophysics

Mentors: Dr. Chris Fragile

Department: Physics and Astronomy

Investigating Truncated Disk Simulations for Signs of Quasi Periodic Oscillations

Many accreting black holes, as well as neutron stars, exhibit rapid quasiperiodic oscillations (QPOs) in their Xray lightcurves, mainly when in the low/hard state. One model that has been especially successful at explaining the so-called type-C, low-frequency (≤10 Hz) QPO is based upon the Lense-Thirring precession of a compact, hot disk (An accretion disk is a structure formed by diffuse material in orbital motion around a massive central body) region.

The kind of precession envisioned by this model has been demonstrated in numerical simulations of isolated, tilted, thick disks. However, none of those simulations have included the surrounding thin disk. For this reason, in order to see the changes that happen when adding the surrounding thin disk, we are proposing to directly simulate a tilted, truncated disk geometry, including the outer thin disk.