Research Highlights

 My group recently performed GRMHD simulations to study the stream-disk interaction in tidal disruption events (TDEs). We found that, assuming the disk is magnetically arrested, jetted TDEs are tilt unstable due to strong interaction between the stream self-intersection outflow, jet, and disk.

This tilt instability is dependent on the strength of the self-intersection of the stream. We found that as the stream becomes less dense compared to the disk, it cannot penetrate to the pericenter radius associated with its orbit. Instead, it begins to mix with the disk as the density ratio approaches unity. In this case, self-intersection weakens substantially, and the jet and disk remain aligned with the black hole's spin.

We propose that changes in the jet tilt can explain rapid order of magnitude declines in X-rays due to relativistic beaming effects. Rapid X-ray declines after several months have been observed in jetted TDEs such as Swift J1644+57. 

https://ui.adsabs.harvard.edu/abs/2025MNRAS.540.1215C/abstract

 In 2023, I led a study as part of the Event Horizon Telescope (EHT) Collaboration to examine the potential of TDE jets as future EHT targets.

Near the peak of their emission, TDEs involving solar mass main sequence stars around black holes of mass 1e6-1e8 solar masses are thought to become super-Eddington. Radiation and magnetic fields act to accelerate powerful outflows in super-Eddington disks, and this hot, magnetized outflow produces radio frequency emission which could be observable.

The numerical simulation below demonstrates large scale outflows driven by weakly magnetized super-Eddington disks accreting at roughly 10 times the Eddington rate. Low density outflows propogate along +/- z.

https://ui.adsabs.harvard.edu/abs/2023MNRAS.519.2812C/abstract