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Observing Lense-Thirring precession in tidal disruption flares
1Astronomy Department, Harvard University, Cambridge, Massachusetts 02138, USA. nstone@cfa.harvard.edu
Physical Review Letters
|March 10, 2012
Summary
Supermassive black holes (SMBHs) can disrupt stars, forming accretion disks. Lense-Thirring precession causes disk evolution and can lead to jet precession and luminosity changes.
Area of Science:
- Astrophysics
- General Relativity
Background:
- Tidal disruption events (TDEs) occur when stars approach supermassive black holes (SMBHs).
- Gas streams from disrupted stars form accretion disks around SMBHs.
- Rotating SMBHs create unique spacetime effects.
Purpose of the Study:
- To investigate the impact of Lense-Thirring precession on accretion disks formed by stellar tidal disruptions.
- To explore the consequences of disk angular momentum evolution.
Main Methods:
- Simulating the behavior of gas streams after stellar tidal disruption.
- Analyzing the effects of Lense-Thirring precession on disk dynamics.
- Examining observational data from events like Swift J164449.3+573451.
Main Results:
- Lense-Thirring precession causes significant time evolution of the disk angular momentum vector.
- Both periodic disk precession and differential precession of debris streams contribute to this evolution.
- Jet precession and periodic modulation of disk luminosity are predicted consequences.
Conclusions:
- The study demonstrates Lense-Thirring precession's crucial role in TDE accretion disk evolution.
- Observed persistent jetted emission in Swift J164449.3+573451 supports jet-SMBH spin axis alignment.
- This mechanism offers explanations for observed phenomena in TDEs.
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