The impact of chemical differentiation of white dwarfs on thermonuclear supernovae

Autores
Bravo, E.; Althaus, Leandro Gabriel; García Berro, E.; Domínguez, I.
Año de publicación
2011
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Aims. Gravitational settling of 22Ne in cooling white dwarfs can affect the outcome of thermonuclear supernovae. We investigate how the supernova energetics and nucleosynthesis are in turn influenced by this process. We use realistic chemical profiles derived from state-of-the-art white dwarf cooling sequences. The cooling sequences provide a link between the white dwarf chemical structure and the age of the supernova progenitor system. Methods. The cooling sequence of a 1 M⊙ white dwarf was computed until freezing using an up-to-date stellar evolutionary code. We computed explosions of both Chandrasekhar mass and sub-Chandrasekhar mass white dwarfs, assuming spherical symmetry and neglecting convective mixing during the pre-supernova carbon simmering phase to maximize the effects of chemical separation. Results. Neither gravitational settling of 22Ne nor chemical differentiation of 12C and 16O have an appreciable impact on the properties of type Ia supernovae, unless there is a direct dependence of the flame properties (density of transition from deflagration to detonation) on the chemical composition. At a fixed transition density, the maximum variation in the supernova magnitude obtained from progenitors of different ages is ∼0.06 mag, and even assuming an unrealistically large diffusion coefficient of 22Ne it would be less than ∼0.09 mag. However, if the transition density depends on the chemical composition (all other things being equal) the oldest SNIa can be as much as 0.4 mag brighter than the youngest ones (in our models the age difference is 7.4 Gyr). In addition, our results show that 22Ne sedimentation cannot be invoked to account for the formation of a central core of stable neutron-rich Fe-group nuclei in the ejecta of sub-Chandrasekhar models, as required by observations of type Ia supernovae.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
Materia
Ciencias Astronómicas
diffusion
distance scale
stars: evolution
stars: interiors
supernovae: general
white dwarfs
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/83962

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/83962
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling The impact of chemical differentiation of white dwarfs on thermonuclear supernovaeBravo, E.Althaus, Leandro GabrielGarcía Berro, E.Domínguez, I.Ciencias Astronómicasdiffusiondistance scalestars: evolutionstars: interiorssupernovae: generalwhite dwarfsAims. Gravitational settling of <SUP>22</SUP>Ne in cooling white dwarfs can affect the outcome of thermonuclear supernovae. We investigate how the supernova energetics and nucleosynthesis are in turn influenced by this process. We use realistic chemical profiles derived from state-of-the-art white dwarf cooling sequences. The cooling sequences provide a link between the white dwarf chemical structure and the age of the supernova progenitor system. Methods. The cooling sequence of a 1 M⊙ white dwarf was computed until freezing using an up-to-date stellar evolutionary code. We computed explosions of both Chandrasekhar mass and sub-Chandrasekhar mass white dwarfs, assuming spherical symmetry and neglecting convective mixing during the pre-supernova carbon simmering phase to maximize the effects of chemical separation. Results. Neither gravitational settling of <SUP>22</SUP>Ne nor chemical differentiation of <SUP>12</SUP>C and <SUP>16</SUP>O have an appreciable impact on the properties of type Ia supernovae, unless there is a direct dependence of the flame properties (density of transition from deflagration to detonation) on the chemical composition. At a fixed transition density, the maximum variation in the supernova magnitude obtained from progenitors of different ages is ∼0.06 mag, and even assuming an unrealistically large diffusion coefficient of <SUP>22</SUP>Ne it would be less than ∼0.09 mag. However, if the transition density depends on the chemical composition (all other things being equal) the oldest SNIa can be as much as 0.4 mag brighter than the youngest ones (in our models the age difference is 7.4 Gyr). In addition, our results show that <SUP>22</SUP>Ne sedimentation cannot be invoked to account for the formation of a central core of stable neutron-rich Fe-group nuclei in the ejecta of sub-Chandrasekhar models, as required by observations of type Ia supernovae.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plata2011info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://sedici.unlp.edu.ar/handle/10915/83962enginfo:eu-repo/semantics/altIdentifier/issn/0004-6361info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201015506info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:16:10Zoai:sedici.unlp.edu.ar:10915/83962Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:16:10.348SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
title The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
spellingShingle The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
Bravo, E.
Ciencias Astronómicas
diffusion
distance scale
stars: evolution
stars: interiors
supernovae: general
white dwarfs
title_short The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
title_full The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
title_fullStr The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
title_full_unstemmed The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
title_sort The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
dc.creator.none.fl_str_mv Bravo, E.
Althaus, Leandro Gabriel
García Berro, E.
Domínguez, I.
author Bravo, E.
author_facet Bravo, E.
Althaus, Leandro Gabriel
García Berro, E.
Domínguez, I.
author_role author
author2 Althaus, Leandro Gabriel
García Berro, E.
Domínguez, I.
author2_role author
author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
diffusion
distance scale
stars: evolution
stars: interiors
supernovae: general
white dwarfs
topic Ciencias Astronómicas
diffusion
distance scale
stars: evolution
stars: interiors
supernovae: general
white dwarfs
dc.description.none.fl_txt_mv Aims. Gravitational settling of <SUP>22</SUP>Ne in cooling white dwarfs can affect the outcome of thermonuclear supernovae. We investigate how the supernova energetics and nucleosynthesis are in turn influenced by this process. We use realistic chemical profiles derived from state-of-the-art white dwarf cooling sequences. The cooling sequences provide a link between the white dwarf chemical structure and the age of the supernova progenitor system. Methods. The cooling sequence of a 1 M⊙ white dwarf was computed until freezing using an up-to-date stellar evolutionary code. We computed explosions of both Chandrasekhar mass and sub-Chandrasekhar mass white dwarfs, assuming spherical symmetry and neglecting convective mixing during the pre-supernova carbon simmering phase to maximize the effects of chemical separation. Results. Neither gravitational settling of <SUP>22</SUP>Ne nor chemical differentiation of <SUP>12</SUP>C and <SUP>16</SUP>O have an appreciable impact on the properties of type Ia supernovae, unless there is a direct dependence of the flame properties (density of transition from deflagration to detonation) on the chemical composition. At a fixed transition density, the maximum variation in the supernova magnitude obtained from progenitors of different ages is ∼0.06 mag, and even assuming an unrealistically large diffusion coefficient of <SUP>22</SUP>Ne it would be less than ∼0.09 mag. However, if the transition density depends on the chemical composition (all other things being equal) the oldest SNIa can be as much as 0.4 mag brighter than the youngest ones (in our models the age difference is 7.4 Gyr). In addition, our results show that <SUP>22</SUP>Ne sedimentation cannot be invoked to account for the formation of a central core of stable neutron-rich Fe-group nuclei in the ejecta of sub-Chandrasekhar models, as required by observations of type Ia supernovae.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
description Aims. Gravitational settling of <SUP>22</SUP>Ne in cooling white dwarfs can affect the outcome of thermonuclear supernovae. We investigate how the supernova energetics and nucleosynthesis are in turn influenced by this process. We use realistic chemical profiles derived from state-of-the-art white dwarf cooling sequences. The cooling sequences provide a link between the white dwarf chemical structure and the age of the supernova progenitor system. Methods. The cooling sequence of a 1 M⊙ white dwarf was computed until freezing using an up-to-date stellar evolutionary code. We computed explosions of both Chandrasekhar mass and sub-Chandrasekhar mass white dwarfs, assuming spherical symmetry and neglecting convective mixing during the pre-supernova carbon simmering phase to maximize the effects of chemical separation. Results. Neither gravitational settling of <SUP>22</SUP>Ne nor chemical differentiation of <SUP>12</SUP>C and <SUP>16</SUP>O have an appreciable impact on the properties of type Ia supernovae, unless there is a direct dependence of the flame properties (density of transition from deflagration to detonation) on the chemical composition. At a fixed transition density, the maximum variation in the supernova magnitude obtained from progenitors of different ages is ∼0.06 mag, and even assuming an unrealistically large diffusion coefficient of <SUP>22</SUP>Ne it would be less than ∼0.09 mag. However, if the transition density depends on the chemical composition (all other things being equal) the oldest SNIa can be as much as 0.4 mag brighter than the youngest ones (in our models the age difference is 7.4 Gyr). In addition, our results show that <SUP>22</SUP>Ne sedimentation cannot be invoked to account for the formation of a central core of stable neutron-rich Fe-group nuclei in the ejecta of sub-Chandrasekhar models, as required by observations of type Ia supernovae.
publishDate 2011
dc.date.none.fl_str_mv 2011
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/83962
url http://sedici.unlp.edu.ar/handle/10915/83962
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0004-6361
info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201015506
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
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instname_str Universidad Nacional de La Plata
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repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
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