Tidally-induced thermonuclear Supernovae

Abstract

We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than $2\times 10^5$ M${}_{\odot }$ swallow a typical 0.6 M${}_{\odot }$ dwarf before their tidal forces can overwhelm the star's self-gravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an X-ray flare close to the Eddington limit of $L_{\mathrm{Edd}}\simeq 10^{41}erg/s{M}_{\mathrm{bh}}/1000M$_\odot$), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events.

8 pages, 2 figures, EuroWD08

References in corpus (21)

• A Fundamental Relation Between Supermassive Black Holes and Their Host Galaxies
• The formation of massive black holes through collision runaway in dense young star clusters
• Stellar disruption by a supermassive black hole: is the light curve really proportional to $t^{-5/3}$?
• A Common Explosion Mechanism for Type Ia Supernovae
• Mergers of neutron star black hole binaries with small mass ratios: nucleosynthesis, gamma-ray bursts and electromagnetic transients
• Hubble Space Telescope Evidence for an Intermediate-Mass Black Hole in the Globular Cluster M15: II. Kinematical Analysis and Dynamical Modeling
• Tidal disruption and ignition of white dwarfs by moderately massive black holes
• Chandra Observations of "The Antennae" Galaxies (NGC 4038/39)
• Gemini and Hubble Space Telescope Evidence for an Intermediate Mass Black Hole in omega Centauri
• The cooling of CO white dwarfs: influence of the internal chemical distribution
• The X-ray Source Population of "The Antennae" Galaxies: X-ray Properties from Chandra and Multiwavelength Associations
• Gravitational Wave and X-ray Signals from Stellar Disruption by a Massive Black Hole
• The chemical composition of White Dwarfs as a test of convective efficiency during core He-burning
• Atypical Thermonuclear Supernovae from Tidally Crushed White Dwarfs
• X-rays from the Globular Cluster G1: Intermediate Mass Black Hole or Low Mass X-ray Binary?
• Radio observations of NGC 2808 and other globular clusters: constraints on intermediate mass black holes
• Shock waves in tidally compressed stars by massive black holes
• The First Type Ia Supernovae: An Empirical Approach to Taming Evolutionary Effects In Dark Energy Surveys from SNe Ia at z>2
• Simulating Black Hole White Dwarf Encounters
• The QSE-reduced αNetwork
• White Dwarfs Near Black Holes: A New Paradigm for Type I Supernovae

Cited by in corpus (3)

• Optical Thermonuclear Transients From Tidal Compression of White Dwarfs as Tracers of the Low End of the Massive Black Hole Mass Function
• Galactic vs. Extragalactic Origin of the Peculiar Transient SCP 06F6
• A Post-Newtonian approach to black hole-fluid systems