The Library
Horizontal spreading of planetary debris accreted by white dwarfs
Tools
Cunningham, T. J., Tremblay, Pier-Emmanuel, Bauer, Evan B., Toloza, Odette, Cukanovaite, Elena, Koester, Detlev, Farihi, Jay, Freytag, Bernd, Gaensicke, B. T., Ludwig, Hans-Günter and Veras, Dimitri (2021) Horizontal spreading of planetary debris accreted by white dwarfs. Monthly Notices of the Royal Astronomical Society, 503 (2). pp. 1646-1667. doi:10.1093/mnras/stab553 ISSN 1365-2966.
|
PDF
WRAP-Horizontal-spreading-planetary-debris-accreted-white-dwarfs-2021.pdf - Accepted Version - Requires a PDF viewer. Download (2086Kb) | Preview |
Official URL: https://doi.org/10.1093/mnras/stab553
Abstract
White dwarfs with metal-polluted atmospheres have been studied widely in the context of the accretion of rocky debris from evolved planetary systems. One open question is the geometry of accretion and how material arrives and mixes in the white dwarf surface layers. Using the three-dimensional (3D) radiation hydrodynamics code co5bold, we present the first transport coefficients in degenerate star atmospheres that describe the advection–diffusion of a passive scalar across the surface plane. We couple newly derived horizontal diffusion coefficients with previously published vertical diffusion coefficients to provide theoretical constraints on surface spreading of metals in white dwarfs. Our grid of 3D simulations probes the vast majority of the parameter space of convective white dwarfs, with pure-hydrogen atmospheres in the effective temperature range of 6000–18 000 K and pure-helium atmospheres in the range of 12 000–34 000 K. Our results suggest that warm hydrogen-rich atmospheres (DA; ${\gtrsim} 13\, 000$ K) and helium-rich atmospheres (DB and DBA; ${\gtrsim} 30\, 000$ K) are unable to efficiently spread the accreted metals across their surface, regardless of the time dependence of accretion. This result may be at odds with the current non-detection of surface abundance variations in white dwarfs with debris discs. For cooler hydrogen- and helium-rich atmospheres, we predict a largely homogeneous distribution of metals across the surface within a vertical diffusion time-scale. This is typically less than 0.1 per cent of disc lifetime estimates, a quantity that is revisited in this paper using the overshoot results. These results have relevance for studies of the bulk composition of evolved planetary systems and models of accretion disc physics.
Item Type: | Journal Article | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Subjects: | Q Science > QB Astronomy | |||||||||||||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Physics | |||||||||||||||
SWORD Depositor: | Library Publications Router | |||||||||||||||
Library of Congress Subject Headings (LCSH): | White dwarf stars, Accretion (Astrophysics), Disks (Astrophysics), Planets -- Atmospheres | |||||||||||||||
Journal or Publication Title: | Monthly Notices of the Royal Astronomical Society | |||||||||||||||
Publisher: | Oxford University Press (OUP) | |||||||||||||||
ISSN: | 1365-2966 | |||||||||||||||
Official Date: | May 2021 | |||||||||||||||
Dates: |
|
|||||||||||||||
Volume: | 503 | |||||||||||||||
Number: | 2 | |||||||||||||||
Page Range: | pp. 1646-1667 | |||||||||||||||
DOI: | 10.1093/mnras/stab553 | |||||||||||||||
Status: | Peer Reviewed | |||||||||||||||
Publication Status: | Published | |||||||||||||||
Reuse Statement (publisher, data, author rights): | This is a pre-copyedited, author-produced version of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record Tim Cunningham, Pier-Emmanuel Tremblay, Evan B Bauer, Odette Toloza, Elena Cukanovaite, Detlev Koester, Jay Farihi, Bernd Freytag, Boris T Gänsicke, Hans-Günter Ludwig, Dimitri Veras, Horizontal spreading of planetary debris accreted by white dwarfs, Monthly Notices of the Royal Astronomical Society, Volume 503, Issue 2, May 2021, Pages 1646–1667 is available online at: https://doi.org/10.1093/mnras/stab553 | |||||||||||||||
Access rights to Published version: | Open Access (Creative Commons) | |||||||||||||||
Date of first compliant deposit: | 13 April 2021 | |||||||||||||||
Date of first compliant Open Access: | 13 April 2021 | |||||||||||||||
RIOXX Funder/Project Grant: |
|
|||||||||||||||
Related URLs: |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year