Radio Emission from the unbound Debris of Tidal Disruption Events

Abstract

When a star gets too close to a supermassive black hole, it is torn apart by the tidal forces. Roughly half of the stellar mass becomes unbound and flies away at tremendous velocities - around $10^4$ km/s. In this work we explore the idea that the shock produced by the interaction of the unbound debris with the ambient medium gives rise to the synchrotron radio emission observed in several TDEs. We use a moving mesh numerical simulation to study the evolution of the unbound debris and the bow shock around it. We find that as the periapse distance of the star decreases, the outflow becomes faster and wider. A tidal disruption event whose periapse distance is a factor of 7 smaller than the tidal radius can account for the radio emission observed in ASASSN-14li. This model also allows us to obtain a more accurate estimate for the gas density around the centre of the host galaxy of ASASSN-14li.

References in corpus (6)

• Ultrafast Outflow in Tidal Disruption Event ASASSN-14li
• Radio observations of the tidal disruption event XMMSL1 J0740$-$85
• Rich: Open Source Hydrodynamic Simulation on a Moving Voronoi Mesh
• Long-term radio and X-ray evolution of the tidal disruption event ASASSN-14li
• The TDE ASASSN-14li and its host resolved at parsec scales with the EVN
• Circumbinary discs from tidal disruption events

Cited by in corpus (8)

• Radio Properties of Tidal Disruption Events
• Delayed Radio Flares from a Tidal Disruption Event
• A radio-emitting outflow produced by the tidal disruption event AT2020vwl
• Radio constraint on outflows from tidal disruption events
• The Influence of Black Hole Binarity on Tidal Disruption Events
• Simulations of Tidal Disruption Events
• Future Simulations of Tidal Disruption Events
• A Mildly Relativistic Outflow Launched Two Years after Disruption in the Tidal Disruption Event AT2018hyz