Tidal double detonation: a new mechanism for a thermonuclear explosion of a white dwarf induced by a tidal disruption event

Abstract

We suggest "tidal double detonation": a new mechanism for a thermonuclear explosion of a white dwarf (WD) induced by a tidal disruption event (TDE). Tidal detonation is also a WD explosion induced by a TDE. In this case, helium (He) and carbon-oxygen (CO) detonation waves incinerate He~WD and CO~WD, respectively. On the other hand, for tidal double detonation, He detonation is first excited in the He shell of a CO~WD, and drives CO detonation in the CO core. We name this mechanism after the double detonation scenario in the context of type Ia supernovae. In this paper, we show tidal double detonation occurs in shallower encounter of a CO~WD with an intermediate mass black hole (IMBH) than simple tidal detonation, performing numerical simulations for CO~WDs with $0.60M_\odot$ with and without a He shell. We expect tidal double detonation spreads opportunity to WD~TDEs illuminating IMBHs.