Runaway accretion of metals from compact debris disks onto white dwarfs

Abstract

It was recently proposed that metal-rich white dwarfs (WDs) accrete their metals from compact debris disks found to exist around more than a dozen of them. At the same time, elemental abundances measured in atmospheres of some WDs imply vigorous metal accretion at rates up to $10^{11}$ g/s, far in excess of what can be supplied solely by Poynting-Robertson drag acting on such debris disks. To explain this observation we propose a model, in which rapid transport of metals from the disk onto the WD naturally results from interaction between this particulate disk and spatially coexisting disk of metallic gas. The latter is fed by evaporation of debris particles at the sublimation radius located at several tens of WD radii. Because of pressure support gaseous disk orbits WD slower than particulate disk. Resultant azimuthal drift between them at speed ~1 m/s causes aerodynamic drag on the disk of solids and drives inward migration of its constituent particles. Upon reaching the sublimation radius particles evaporate, enhancing the density of metallic gaseous disk and leading to positive feedback. Under favorable circumstances (low viscosity in the disk of metallic gas and efficient aerodynamic coupling between the disks) system evolves in a runaway fashion, destroying debris disk on time scale of $\sim 10^5$ yr, and giving rise to high metal accretion rates up to $10^{10}-10^{11}$ g/s, in agreement with observations.

5 pages, 2 figures, submitted to ApJL

References in corpus (7)

• A gaseous metal disk around a white dwarf
• Pollution of single white dwarfs by accretion of many small asteroids
• Six White Dwarfs with Circumstellar Silicates
• Metal accretion onto white dwarfs caused by Poynting-Robertson drag on their debris disks
• Echoes of a decaying planetary system: the gaseous and dusty disks surrounding three white dwarfs
• SDSSJ104341.53+085558.2: A second white dwarf with a gaseous debris disc
• SOPHIE velocimetry of Kepler transit candidates. I. Detection of the low-mass white dwarf KOI-74b

Cited by in corpus (94)

• The frequency of planetary debris around young white dwarfs
• The Link Between Planetary Systems, Dusty White Dwarfs, and Metal Polluted White Dwarfs
• Circumstellar Debris and Pollution at White Dwarf Stars
• Global Models of Runaway Accretion in White Dwarf Debris Disks
• Constraints on the Lifetimes of Disks Resulting from Tidally Destroyed Rocky Planetary Bodies
• The frequency and infrared brightness of circumstellar discs at white dwarfs
• Detailed compositional analysis of the heavily polluted DBZ white dwarf SDSS J073842.56+183509.06: A window on planet formation?
• Stochastic accretion of planetesimals onto white dwarfs: constraints on the mass distribution of accreted material from atmospheric pollution
• Unstable low-mass planetary systems as drivers of white dwarf pollution
• Two Beyond-Primitive Extrasolar Planetesimals
• Doppler-imaging of the planetary debris disc at the white dwarf SDSS J122859.93+104032.9
• Detectable close-in planets around white dwarfs through late unpacking
• A Trio of Metal-Rich Dust and Gas Disks Found Orbiting Candidate White Dwarfs with K-Band Excess
• The unbiased frequency of planetary signatures around single and binary white dwarfs using $Spitzer$ and $Hubble$
• The Frequency of Debris Disks at White Dwarfs
• Variable Emission from a Gaseous Disc around a Metal-Polluted White Dwarf
• Spitzer Observations of White Dwarfs: the Missing Planetary Debris Around DZ Stars
• Scars of Intense Accretion Episodes at Metal-Rich White Dwarfs
• Water Fractions in Extrasolar Planetesimals
• Hydrogen delivery onto white dwarfs from remnant exo-Oort cloud comets
• Inner edges of compact debris disks around metal-rich white dwarfs
• Two Extrasolar Asteroids with Low Volatile-Element Mass Fractions
• Precise Atmospheric Parameters for the Shortest Period Binary White Dwarfs: Gravitational Waves, Metals, and Pulsations
• Numerical Simulations of Collisional Cascades at the Roche Limits of White Dwarf Stars
• Explaining the variability of WD 1145+017 with simulations of asteroid tidal disruption
• The frequency of gaseous debris discs around white dwarfs
• Does a Differentiated, Carbonate-Rich, Rocky Object Pollute the White Dwarf SDSSJ104341.53+085558.2?
• The Drop during Less than 300 days of a Dusty White Dwarf's Infrared Luminosity
• A Spitzer Space Telescope Study of the Debris Disks around four SDSS White Dwarfs
• The Occurrence of Wide-Orbit Planets in Binary Star Systems
• Tidal disruption of planetary bodies by white dwarfs II: Debris disc structure and ejected interstellar asteroids
• Infrared observations of white dwarfs and the implications for the accretion of dusty planetary material
• Deposition of steeply infalling debris around white dwarf stars
• Transient outburst events from tidally disrupted asteroids near white dwarfs
• Global modeling of radiatively driven accretion of metals from compact debris disks onto the white dwarfs
• The Fate of Exomoons in White Dwarf Planetary Systems
• Polluted White Dwarfs: Mixing Regions and Diffusion Timescales
• Numerical Simulations of Gaseous Disks Generated from Collisional Cascades at the Roche Limits of White Dwarf Stars
• White dwarfs with planetary remnants in the era of Gaia I: six emission line systems
• Dust Production and Depletion in Evolved Planetary Systems
• Serendipitous Discovery of Nine White Dwarfs With Gaseous Debris Disks
• Evidence for eccentric, precessing gaseous debris in the circumstellar absorption towards WD 1145+017
• Exoplanet recycling in massive white-dwarf debris discs
• The dust never settles: collisional production of gas and dust in evolved planetary systems
• Post main sequence evolution of icy minor planets: Implications for water retention and white dwarf pollution
• Another one grinds the dust: Variability of the planetary debris disc at the white dwarf SDSS J104341.53+085558.2
• Bayesian constraints on the origin and geology of exo-planetary material using a population of externally polluted white dwarfs
• Infrared Variability of Two Dusty White Dwarfs
• Increases to Inferred Rates of Planetesimal Accretion Due to Thermohaline Mixing in Metal Accreting White Dwarfs
• A dearth of small particles in the transiting material around the white dwarf WD 1145+017
• The fates of Solar system analogues with one additional distant planet
• Dusty WDs in the $WISE$ All Sky Survey $\cap$ SDSS
• 1I/2017 'Oumuamua-like Interstellar Asteroids as Possible Messengers from the Dead Stars
• Linking long-term planetary $N$-body simulations with periodic orbits: application to white dwarf pollution
• Fast and Slow Precession of Gaseous Debris Disks Around Planet-Accreting White Dwarfs
• The lifetimes of planetary debris discs around white dwarfs
• New chondritic bodies identified in eight oxygen-bearing white dwarfs
• Embedding planetesimals into white dwarf discs from large distances
• SDSS J074511.56+194926.5: Discovery of a Metal-Rich and Tidally Distorted Extremely Low Mass White Dwarf
• Binary star influence on post-main-sequence multi-planet stability
• Accretion of tidally disrupted asteroids onto white dwarfs: direct accretion versus disk processing
• High-eccentricity migration of planetesimals around polluted white dwarfs
• Collisions in a gas-rich white dwarf planetary debris disc
• Effects of non-Kozai mutual inclinations on two-planet system stability through all phases of stellar evolution
• Where are the Extrasolar Mercuries?
• Post main sequence evolution of icy minor planets II: water retention and white dwarf pollution around massive progenitor stars
• Post-main-sequence evolution of icy minor planets. III. water retention in dwarf planets and exo-moons and implications for white dwarf pollution
• The Geometry of the G29-38 White Dwarf Dust Disk from Radiative Transfer Modeling
• Chaotic rotation and evolution of asteroids and small planets in high-eccentricity orbits around white dwarfs
• Orbit decay of 2-100 au planetary remnants around white dwarfs with no gravitational assistance from planets
• Dynamical mass and multiplicity constraints on co-orbital bodies around stars
• Metal pollution of the solar white dwarf by solar system small bodies
• Formation of eccentric gas discs from sublimating or partially disrupted asteroids orbiting white dwarfs
• Modeling the Evolution of Silicate/Volatile Accretion Discs around White Dwarfs
• The entry geometry and velocity of planetary debris into the Roche sphere of a white dwarf
• Constraining planet formation around 6$M_{\odot }$-8$M_{\odot }$ stars
• Asynchronous accretion can mimic diverse white dwarf pollutants II: water content
• A power law decay evolution scenario for polluted single white dwarfs
• Disk or Companion: Characterizing Excess Infrared Flux in Seven White Dwarf Systems with Near-Infrared Spectroscopy
• Characterizing the Chemistry of Planetary Materials Around White Dwarf Stars
• The grain size survival threshold in one-planet post-main-sequence exoplanetary systems
• Velocity-imaging the rapidly precessing planetary disc around the white dwarf HE 1349-2305 using Doppler tomography
• The Effect of a Magnetic Field on the Dynamics of Debris Discs Around White Dwarfs
• Non-LTE spectral models for the gaseous debris-disk component of Ton 345
• Rapid destruction of planetary debris around white dwarfs through aeolian erosion
• Can tidal evolution lead to close-in planetary bodies around white dwarfs II: volcanism and transits
• Post-main sequence thermal evolution of planetesimals
• Planetesimals drifting through dusty and gaseous white dwarf debris discs: Types I, II and III-like migration
• White dwarf magnetospheres: Shielding volatile content of icy objects and implications for volatile pollution scarcity
• Origin of Ca II emission around polluted white dwarfs
• Partial disruption of a planet around a white dwarf: the effect of perturbation from the remnant planet on the accretion
• The Elemental Compositions of Extrasolar Planetesimals
• White dwarf constraints on geological processes at the population level
• I Can Do It With A Broken Planetesimal: Characterising the planetary debris in heavily polluted cool white dwarfs