May 27, 2019 to June 5, 2019
Europe/Paris timezone

S. Chakraborty: Jet inclination relative to the black hole spin for the TDE Swift J1644+57

May 30, 2019, 6:25 PM
Amphitheatre (Cargèse)



Institut d’Etudes Scientifiques de Cargèse Menasina F-20130 CARGÈSE


Sudip Chakraborty (Tata Institute of Fundamental Research, Mumbai, India)


An estimate of the jet inclination relative to the accreting black hole's spin can be useful to probe the jet triggering mechanism and the disc-jet coupling. Tidal Disruption Event (TDE) of a star by a supermassive spinning black hole provides a unique astrophysical laboratory to study the jet direction through the possibility of jet precession, induced by the Lense-Thirring precession of the disc or by other mechanisms. In this work, we investigate the Swift XRT light curve of a well-sampled jetted TDE, Swift J1644+57. We use a new method to compare some useful aspects of the dips of this X-ray light curve with our jet precession model to find an upper limit of the jet inclination angle. This method does not require a known jet precession period and works even if many dips are not due to jet precession. Employing this method for the thick disc regime of the X-ray light curve, we conclude that the jet inclination with respect to the black hole spin axis, or the black hole spin-precession axis if the spin axis precesses, is likely less than 10 degrees for Swift J1644+57. We will then discuss its effect on the stellar dynamics near the supermassive black hole.

Presentation materials