An ancient double degenerate merger in the Milky Way halo

Adela Kawka; Stéphane Vennes; Lilia Ferrario

doi:10.1093/mnrasl/slz165

An ancient double degenerate merger in the Milky Way halo

Adela Kawka^*, Stéphane Vennes, Lilia Ferrario

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

13 Citations (Scopus)

Abstract

We present an analysis and re-appraisal of the massive, carbon-enriched (DQ) white dwarf (WD) LP 93-21. Its high mass (≈1.1 M_⊙) and membership to the class of warm DQ WDs, combined with its peculiar halo kinematics suggest that this object is the product of an ancient stellar merger event, most likely that of two WDs. Furthermore, the kinematics places this object on a highly retrograde orbit driven by the accretion of a dwarf galaxy on to the Milky Way that occurred at a redshift greater than 1.5. As the product of a stellar merger LP 93-21 is probably representative of the whole class of warm/hot DQ WDs.

Original language	English
Pages (from-to)	L40-L45
Journal	Monthly Notices of the Royal Astronomical Society: Letters
Volume	491
Issue number	1
DOIs	https://doi.org/10.1093/mnrasl/slz165
Publication status	Published - 1 Jan 2020

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title = "An ancient double degenerate merger in the Milky Way halo",

abstract = "We present an analysis and re-appraisal of the massive, carbon-enriched (DQ) white dwarf (WD) LP 93-21. Its high mass (≈1.1 M⊙) and membership to the class of warm DQ WDs, combined with its peculiar halo kinematics suggest that this object is the product of an ancient stellar merger event, most likely that of two WDs. Furthermore, the kinematics places this object on a highly retrograde orbit driven by the accretion of a dwarf galaxy on to the Milky Way that occurred at a redshift greater than 1.5. As the product of a stellar merger LP 93-21 is probably representative of the whole class of warm/hot DQ WDs.",

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doi = "10.1093/mnrasl/slz165",

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AU - Kawka, Adela

AU - Vennes, Stéphane

AU - Ferrario, Lilia

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AB - We present an analysis and re-appraisal of the massive, carbon-enriched (DQ) white dwarf (WD) LP 93-21. Its high mass (≈1.1 M⊙) and membership to the class of warm DQ WDs, combined with its peculiar halo kinematics suggest that this object is the product of an ancient stellar merger event, most likely that of two WDs. Furthermore, the kinematics places this object on a highly retrograde orbit driven by the accretion of a dwarf galaxy on to the Milky Way that occurred at a redshift greater than 1.5. As the product of a stellar merger LP 93-21 is probably representative of the whole class of warm/hot DQ WDs.

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KW - Galaxy: structure

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JO - Monthly Notices of the Royal Astronomical Society: Letters

JF - Monthly Notices of the Royal Astronomical Society: Letters

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An ancient double degenerate merger in the Milky Way halo

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