A Study of the X-ray Periodicities in the Remarkable Transient Source Swift J1644+57
Abstract
Swift J1644+57 was discovered when it exhibited bright X-ray activity that was believed to be triggered from the infall of a tidally disrupted star near a massive black hole. The observation of a tidal disruption event (TDE) can provide clues to the geometry and physics near the black hole. If a jet forms, as we think happened with Swift J1644+57, it can provide data to study jet creation and the density of matter in a possible accretion disc. We have analyzed Swift X-ray Telescope (XRT) observations of Swift J1644+57 from initial onset to 502 days after TDE onset. We used a Z-transform Discrete Correlation Function (ZDCF) to search for periodicities in the Swift X-ray light curve. We analyzed the X-ray light curve in five time regions, including 0 to 4.5 days after TDE onset, 4.5 to 55 days after TDE onset, 55 to 104 days after TDE onset, 104 to 145 days after TDE onset, and 145 to 502 days after TDE onset. After implementing red and white noise reduction modeling to our ZDCF analysis, we found plausible detections of periodicities. We briefly discuss implications of these periods on the geometry and feeding of the tidal disruption event.
- Publication:
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AAS/High Energy Astrophysics Division #15
- Pub Date:
- April 2016
- Bibcode:
- 2016HEAD...1510631G