The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo

Autores
Camacho, J.; Torres, S.; Isern, J.; Althaus, Leandro Gabriel; García-Berro, E.
Año de publicación
2007
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Context. The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. White dwarfs have been proposed to explain these results and, hence, to contribute significantly to the mass budget of our Galaxy. However, several constraints on the role played by regular carbon-oxygen white dwarfs exist. Aims. Massive white dwarfs are thought to be made of a mixture of oxygen and neon. Correspondingly, their cooling rate is larger than those of typical carbon-oxygen white dwarfs and they fade to invisibility in short timescales. Consequently, they constitute a good candidate for explaining the microlensing results. Methods. Here, we examine in detail this hypothesis by using the most recent and up-to-date cooling tracks for massive white dwarfs and a Monte Carlo simulator which takes into account the most relevant Galactic inputs. Results. We find that oxygen-neon white dwarfs cannot account for a substantial fraction of the microlensing depth towards the LMC, independently of the adopted initial mass function, although some microlensing events could be due to oxygen-neon white dwarfs. Conclusions. The white dwarf population contributes at most a 5% to the mass of the Galactic halo.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
Materia
Ciencias Astronómicas
Galaxy: halo
Galaxy: stellar content
Galaxy: structure
Stars: luminosity function, mass function
Stars: 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:10915/83215
Acceder
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oai_identifier_str oai:sedici.unlp.edu.ar:10915/83215
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic haloCamacho, J.Torres, S.Isern, J.Althaus, Leandro GabrielGarcía-Berro, E.Ciencias AstronómicasGalaxy: haloGalaxy: stellar contentGalaxy: structureStars: luminosity function, mass functionStars: white dwarfsContext. The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. White dwarfs have been proposed to explain these results and, hence, to contribute significantly to the mass budget of our Galaxy. However, several constraints on the role played by regular carbon-oxygen white dwarfs exist. Aims. Massive white dwarfs are thought to be made of a mixture of oxygen and neon. Correspondingly, their cooling rate is larger than those of typical carbon-oxygen white dwarfs and they fade to invisibility in short timescales. Consequently, they constitute a good candidate for explaining the microlensing results. Methods. Here, we examine in detail this hypothesis by using the most recent and up-to-date cooling tracks for massive white dwarfs and a Monte Carlo simulator which takes into account the most relevant Galactic inputs. Results. We find that oxygen-neon white dwarfs cannot account for a substantial fraction of the microlensing depth towards the LMC, independently of the adopted initial mass function, although some microlensing events could be due to oxygen-neon white dwarfs. Conclusions. The white dwarf population contributes at most a 5% to the mass of the Galactic halo.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plata2007info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf151-158http://sedici.unlp.edu.ar/handle/10915/83215enginfo:eu-repo/semantics/altIdentifier/issn/0004-6361info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:20077714info: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:UNLP2025-09-29T11:15:41Zoai:sedici.unlp.edu.ar:10915/83215Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:42.146SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo
title The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo
spellingShingle The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo
Camacho, J.
Ciencias Astronómicas
Galaxy: halo
Galaxy: stellar content
Galaxy: structure
Stars: luminosity function, mass function
Stars: white dwarfs
title_short The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo
title_full The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo
title_fullStr The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo
title_full_unstemmed The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo
title_sort The contribution of oxygen-neon white dwarfs to the MACHO content of the Galactic halo
dc.creator.none.fl_str_mv Camacho, J.
Torres, S.
Isern, J.
Althaus, Leandro Gabriel
García-Berro, E.
author Camacho, J.
author_facet Camacho, J.
Torres, S.
Isern, J.
Althaus, Leandro Gabriel
García-Berro, E.
author_role author
author2 Torres, S.
Isern, J.
Althaus, Leandro Gabriel
García-Berro, E.
author2_role author
author
author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
Galaxy: halo
Galaxy: stellar content
Galaxy: structure
Stars: luminosity function, mass function
Stars: white dwarfs
topic Ciencias Astronómicas
Galaxy: halo
Galaxy: stellar content
Galaxy: structure
Stars: luminosity function, mass function
Stars: white dwarfs
dc.description.none.fl_txt_mv Context. The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. White dwarfs have been proposed to explain these results and, hence, to contribute significantly to the mass budget of our Galaxy. However, several constraints on the role played by regular carbon-oxygen white dwarfs exist. Aims. Massive white dwarfs are thought to be made of a mixture of oxygen and neon. Correspondingly, their cooling rate is larger than those of typical carbon-oxygen white dwarfs and they fade to invisibility in short timescales. Consequently, they constitute a good candidate for explaining the microlensing results. Methods. Here, we examine in detail this hypothesis by using the most recent and up-to-date cooling tracks for massive white dwarfs and a Monte Carlo simulator which takes into account the most relevant Galactic inputs. Results. We find that oxygen-neon white dwarfs cannot account for a substantial fraction of the microlensing depth towards the LMC, independently of the adopted initial mass function, although some microlensing events could be due to oxygen-neon white dwarfs. Conclusions. The white dwarf population contributes at most a 5% to the mass of the Galactic halo.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
description Context. The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. White dwarfs have been proposed to explain these results and, hence, to contribute significantly to the mass budget of our Galaxy. However, several constraints on the role played by regular carbon-oxygen white dwarfs exist. Aims. Massive white dwarfs are thought to be made of a mixture of oxygen and neon. Correspondingly, their cooling rate is larger than those of typical carbon-oxygen white dwarfs and they fade to invisibility in short timescales. Consequently, they constitute a good candidate for explaining the microlensing results. Methods. Here, we examine in detail this hypothesis by using the most recent and up-to-date cooling tracks for massive white dwarfs and a Monte Carlo simulator which takes into account the most relevant Galactic inputs. Results. We find that oxygen-neon white dwarfs cannot account for a substantial fraction of the microlensing depth towards the LMC, independently of the adopted initial mass function, although some microlensing events could be due to oxygen-neon white dwarfs. Conclusions. The white dwarf population contributes at most a 5% to the mass of the Galactic halo.
publishDate 2007
dc.date.none.fl_str_mv 2007
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/10915/83215
url http://sedici.unlp.edu.ar/handle/10915/83215
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/10.1051/0004-6361:20077714
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
151-158
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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score 13.070432

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