Numerical-relativity simulation for tidal disruption of white dwarfs by a supermassive black hole

Abstract

We study tidal disruption of white dwarfs in elliptic orbits with the eccentricity of ∼1/3-2/3 by a nonspinning supermassive black hole of mass MBH=105M⊙ in fully general relativistic simulations targeting the extreme mass-ratio inspiral leading eventually to tidal disruption. Numerical-relativity simulations are performed by employing a suitable formulation in which the weak self-gravity of white dwarfs is accurately solved. We reconfirm that tidal disruption occurs for white dwarfs of the typical mass of ∼0.6M⊙ and radius ≈1.2×104 km near the marginally bound orbit around a nonspinning black hole with MBH≲4×105M⊙.