Merger of a White Dwarf-Neutron Star Binary to $10^{29}$ Carat Diamonds: Origin of the Pulsar Planets

Abstract

We show that the merger and tidal disruption of a C/O white dwarf (WD) by a neutron star (NS) binary companion provides a natural formation scenario for the PSR B1257+12 planetary system. Starting with initial conditions for the debris disk produced of the disrupted WD, we model its long term viscous evolution, including for the first time the effects of mass and angular momentum loss during the early radiatively inefficient accretion flow (RIAF) phase and accounting for the unusual C/O composition on the disk opacity. For plausible values of the disk viscosity $\alpha \sim 10^{-3}-10^{-2}$ and the RIAF mass loss efficiency, we find that the disk mass remaining near the planet formation radius at the time of solid condensation is sufficient to explain the pulsar planets. Rapid rocky planet formation via gravitational instability of the solid carbon-dominated disk is facilitated by the suppression of vertical shear instabilities due to the high solid-to-gas ratio. Additional evidence supporting a WD-NS merger scenario includes (1) the low observed occurrence rate of pulsar planets ($\lesssim 1\%$ of NS birth), comparable to the expected WD-NS merger rate; (2) accretion by the NS during the RIAF phase is sufficient to spin PSR B1257+12 up to its observed 6 ms period; (3) similar models of `low angular momentum' disks, such as those produced from supernova fallback, find insufficient mass reaching the planet formation radius. The unusually high space velocity of PSR B1257+12 of $\gtrsim 326{\mathrm{km}\mathrm{s}}^{-1}$ suggests a possible connection to the Calcium-rich transients, dim supernovae which occur in the outskirts of their host galaxies and were proposed to result from mergers of WD-NS binaries receiving SN kicks. The C/O disk composition implied by our model likely results in carbon-rich planets with diamond interiors.

arXiv comment15 pages, 6 figures, submitted to MNRAS

References in corpus (54)

• Collapsars - Gamma-Ray Bursts and Explosions in "Failed Supernovae"
• Spectral Energy Distributions of T Tauri Stars With Passive Circumstellar Disks
• On the Fate of Gas Accreting at a Low Rate onto a Black Hole
• General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes
• Dust coagulation in protoplanetary disks: a rapid depletion of small grains
• GRMHD Simulations of Magnetized Advection Dominated Accretion on a Non-Spinning Black Hole: Role of Outflows
• Planetesimal Formation by Gravitational Instability
• The Formation Rate, Mass and Luminosity Functions of DA White Dwarfs from the Palomar Green Survey
• Photoevaporation of Circumstellar Disks due to External FUV Radiation in Stellar Aggregates
• A Global Three Dimensional Radiation Magneto-hydrodynamic Simulation of Super-Eddington Accretion Disks
• Constraining the Equation of State with Moment of Inertia Measurements
• Hydrodynamical Non-radiative Accretion Flows in Two-Dimensions
• A faint type of supernova from a white dwarf with a helium-rich companion
• A Debris Disk Around An Isolated Young Neutron Star
• The Runts of the Litter: Why planets formed through gravitational instability can only be failed binary stars
• Local Magnetohydrodynamical Models of Layered Accretion Disks
• Sustained Magnetorotational Turbulence in Local Simulations of Stratified Disks with Zero Net Magnetic Flux
• The Long-Term Evolution of Double White Dwarf Mergers
• Spectral energy distributions of selfgravitating QSO discs
• Calcium-rich gap transients in the remote outskirts of galaxies
• Time-Dependent Models of Accretion Disks Formed from Compact Object Mergers
• Numerical Simulation of Hot Accretion Flows (I): A Large Radial Dynamical Range and the Density Profile of Accretion Flow
• Low-temperature gas opacity - AESOPUS: a versatile and quick computational tool
• Two-dimensional models of hydrodynamical accretion flows into black holes
• X-ray Insights into the Nature of PHL 1811 Analogs and Weak Emission-Line Quasars: Unification with a Geometrically Thick Accretion Disk?
• A Magnetohydrodynamic Nonradiative Accretion Flow in Three Dimensions
• Powerful radiative jets in super-critical accretion disks around non-spinning black holes
• Merging White Dwarf/Black Hole Binaries and Gamma-Ray Bursts
• Tides and Tidal Engulfment in Post-Main Sequence Binaries: Period Gaps for Planets and Brown Dwarfs Around White Dwarfs
• Echoes of a decaying planetary system: the gaseous and dusty disks surrounding three white dwarfs
• Evolution of Accretion Disks in Tidal Disruption Events
• Masses and orbital inclinations of planets in the PSR B1257+12 system
• Implications of PSR J0737-3039B for the Galactic NS-NS Binary Merger Rate
• Nuclear-dominated accretion and subluminous supernovae from the merger of a white dwarf with a neutron star or black hole
• The Viscous Evolution of White Dwarf Merger Remnants
• The fate of fallback matter around newly born compact objects
• A new type of long gamma--ray burst
• Stability and Evolution of Supernova Fallback Disks
• Time dependent models of accretion disks with nuclear burning following the tidal disruption of a white dwarf by a neutron star
• Nickel-Rich Outflows from Accretion Disks Formed by the Accretion-Induced Collapse of White Dwarfs
• Iron Opacity Bump Changes the Stability and Structure of Accretion Disks in Active Galactic Nuclei
• Nuclear Dominated Accretion Flows in Two Dimensions. I. Torus Evolution with Parametric Microphysics
• The merger of binary white dwarf-neutron stars: Simulations in full general relativity
• Properties of Carbon-Oxygen White Dwarfs From Monte Carlo Stellar Models
• Dwarf Nova Outbursts with Magnetorotational Turbulence
• Implications of the PSR 1257+12 Planetary System for Isolated Millisecond Pulsars
• The Evolution of Protoplanetary Disks Around Millisecond Pulsars: The PSR 1257 +12 System
• Pulsar Binary Birthrates with Spin-Opening Angle Correlations
• Hubble Space Telescope observations of the host galaxies and environments of calcium-rich supernovae
• Limits on Planet Formation Around Young Pulsars and Implications for Supernova Fallback Disks
• The Pulsar Planets: A Test Case of Terrestrial Planet Assembly
• X-ray emission from the planet pulsar B1257+12
• The interplay between chemistry and nucleation in the formation of carbonaceous dust in supernova ejecta
• CEMP stars: possible hosts to carbon planets in the early universe

Cited by in corpus (19)

• Two New Calcium-Rich Gap Transients in Group and Cluster Environments
• The demographics of neutron star - white dwarf mergers: rates, delay-time distributions and progenitors
• Neutron star - white dwarf mergers: Early evolution, physical properties, and outcomes
• Pre-merger electromagnetic counterparts of binary compact stars
• Transients from ONe White-Dwarf - Neutron-Star/Black-Hole Mergers
• Nuclear Dominated Accretion Flows in Two Dimensions. II. Ejecta dynamics and nucleosynthesis for CO and ONe white dwarfs
• Exoplanet recycling in massive white-dwarf debris discs
• Faint rapid red transients from Neutron star -- CO white-dwarf mergers
• Magnetars from Neutron Star--White Dwarf Mergers: Application to Fast Radio Bursts
• Black widow formation by pulsar irradiation and sustained magnetic braking
• Orbital Evolution of Neutron-Star -- White-Dwarf Binaries by Roche-Lobe Overflow and Gravitational Wave Radiation
• A model of neutron-star--white-dwarf collision for fast radio bursts
• Transients from the Cataclysmic Deaths of Cataclysmic Variables
• Constraining planet formation around 6$M_{\odot }$-8$M_{\odot }$ stars
• Tetrahedral hydrocarbon nanoparticles in space: X-ray spectra
• Lens Flare: Magnified X-Ray Binaries as Passive Beacons in SETI
• Prospects for detecting neutron star-white dwarf mergers with decihertz gravitational-wave observatories
• Second-generation planet formation after tidal disruption from common envelope evolution
• The Head-on Collision of a Neutron Star with a White Dwarf