Propagation of a Precessing Jet in the Envelope of Tidal Disruption Events

Abstract It is likely that the disk of a tidal disruption event (TDE) is misaligned with respect to the equatorial plane of the spinning supermassive black hole (SMBH), since the initial stellar orbit before disruption most likely has an inclined orbital plane. Such a misaligned disk undergoes Lense–Thirring precession around the SMBH spin axis, leading to a precessing jet if launched in the vicinity of the SMBH and aligned with the disk angular momentum. The bound debris can also build a thick envelope that powers optical emission. In this work, we study the propagation of the precessing jet in the TDE envelope. We adopt a “zero-Bernoulli accretion” (ZEBRA) envelope model. An episodic jet will be observed if the line of sight is just at the envelope pole direction and θ LT = θ env , since the jet can freely escape from this low-density rotation funnel, where θ LT and θ env are the jet precessing angle and the angle between the envelope polar axis and the SMBH spin axis, respectively. The jet will be choked at other directions. For θ LT < θ env , the jets can also break out of the envelope for very small precession angle θ LT or if the jet is aligned with SMBH spin. If the jet is choked within the envelope, the radiation produced during the cocoon shock breakout will imprint characteristic signatures on the X-ray emission, such as low-amplitude fluctuation in the light curve.