A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars

Autores
Martins, F.; Simón Díaz, S.; Barbá, Rodolfo Héctor; Gamen, Roberto Claudio; Ekström, S.
Año de publicación
2017
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Context. Massive star evolution remains only partly constrained. In particular, the exact role of rotation has been questioned by puzzling properties of OB stars in the Magellanic Clouds. Aims. Our goal is to study the relation between surface chemical composition and rotational velocity, and to test predictions of evolutionary models including rotation. Methods. We have performed a spectroscopic analysis of a sample of fifteen Galactic O7-8 giant stars. This sample is homogeneous in terms of mass, metallicity and evolutionary state. It is made of stars with a wide range of projected rotational velocities. Results. We show that the sample stars are located on the second half of the main sequence, in a relatively narrow mass range (25-40 M⊙ ). Almost all stars with projected rotational velocities above 100 km s -1 have N/C ratios about ten times the initial value. Below 100 km s -1 a wide range of N/C values is observed. The relation between N/C and surface gravity is well reproduced by various sets of models. Some evolutionary models including rotation are also able to consistently explain slowly rotating, highly enriched stars. This is due to differential rotation which efficiently transports nucleosynthesis products and allows the surface to rotate slower than the core. In addition, angular momentum removal by winds amplifies surface braking on the main sequence. Comparison of the surface composition of O7-8 giant stars with a sample of B stars with initial masses about four times smaller reveal that chemical enrichment scales with initial mass, as expected from theory. Conclusions. Although evolutionary models that include rotation face difficulties in explaining the chemical properties of O- and B-type stars at low metallicity, some of them can consistently account for the properties of main-sequence Galactic O stars in the mass range 25-40 M ⊙.
Instituto de Astrofísica de La Plata
Materia
Ciencias Astronómicas
Stars: abundances
Stars: atmospheres
Stars: early-type
Stars: fundamental parameters
Stars: massive
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:10915/87119

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/87119
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant starsMartins, F.Simón Díaz, S.Barbá, Rodolfo HéctorGamen, Roberto ClaudioEkström, S.Ciencias AstronómicasStars: abundancesStars: atmospheresStars: early-typeStars: fundamental parametersStars: massiveContext. Massive star evolution remains only partly constrained. In particular, the exact role of rotation has been questioned by puzzling properties of OB stars in the Magellanic Clouds. Aims. Our goal is to study the relation between surface chemical composition and rotational velocity, and to test predictions of evolutionary models including rotation. Methods. We have performed a spectroscopic analysis of a sample of fifteen Galactic O7-8 giant stars. This sample is homogeneous in terms of mass, metallicity and evolutionary state. It is made of stars with a wide range of projected rotational velocities. Results. We show that the sample stars are located on the second half of the main sequence, in a relatively narrow mass range (25-40 M⊙ ). Almost all stars with projected rotational velocities above 100 km s -1 have N/C ratios about ten times the initial value. Below 100 km s -1 a wide range of N/C values is observed. The relation between N/C and surface gravity is well reproduced by various sets of models. Some evolutionary models including rotation are also able to consistently explain slowly rotating, highly enriched stars. This is due to differential rotation which efficiently transports nucleosynthesis products and allows the surface to rotate slower than the core. In addition, angular momentum removal by winds amplifies surface braking on the main sequence. Comparison of the surface composition of O7-8 giant stars with a sample of B stars with initial masses about four times smaller reveal that chemical enrichment scales with initial mass, as expected from theory. Conclusions. Although evolutionary models that include rotation face difficulties in explaining the chemical properties of O- and B-type stars at low metallicity, some of them can consistently account for the properties of main-sequence Galactic O stars in the mass range 25-40 M ⊙.Instituto de Astrofísica de La Plata2017info: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/10915/87119enginfo:eu-repo/semantics/altIdentifier/issn/0004-6361info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201629548info: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:UNLP2025-09-29T11:17:14Zoai:sedici.unlp.edu.ar:10915/87119Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:17:15.251SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars
title A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars
spellingShingle A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars
Martins, F.
Ciencias Astronómicas
Stars: abundances
Stars: atmospheres
Stars: early-type
Stars: fundamental parameters
Stars: massive
title_short A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars
title_full A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars
title_fullStr A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars
title_full_unstemmed A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars
title_sort A study of the effect of rotational mixing on massive stars evolution: Surface abundances of Galactic O7-8 giant stars
dc.creator.none.fl_str_mv Martins, F.
Simón Díaz, S.
Barbá, Rodolfo Héctor
Gamen, Roberto Claudio
Ekström, S.
author Martins, F.
author_facet Martins, F.
Simón Díaz, S.
Barbá, Rodolfo Héctor
Gamen, Roberto Claudio
Ekström, S.
author_role author
author2 Simón Díaz, S.
Barbá, Rodolfo Héctor
Gamen, Roberto Claudio
Ekström, S.
author2_role author
author
author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
Stars: abundances
Stars: atmospheres
Stars: early-type
Stars: fundamental parameters
Stars: massive
topic Ciencias Astronómicas
Stars: abundances
Stars: atmospheres
Stars: early-type
Stars: fundamental parameters
Stars: massive
dc.description.none.fl_txt_mv Context. Massive star evolution remains only partly constrained. In particular, the exact role of rotation has been questioned by puzzling properties of OB stars in the Magellanic Clouds. Aims. Our goal is to study the relation between surface chemical composition and rotational velocity, and to test predictions of evolutionary models including rotation. Methods. We have performed a spectroscopic analysis of a sample of fifteen Galactic O7-8 giant stars. This sample is homogeneous in terms of mass, metallicity and evolutionary state. It is made of stars with a wide range of projected rotational velocities. Results. We show that the sample stars are located on the second half of the main sequence, in a relatively narrow mass range (25-40 M⊙ ). Almost all stars with projected rotational velocities above 100 km s -1 have N/C ratios about ten times the initial value. Below 100 km s -1 a wide range of N/C values is observed. The relation between N/C and surface gravity is well reproduced by various sets of models. Some evolutionary models including rotation are also able to consistently explain slowly rotating, highly enriched stars. This is due to differential rotation which efficiently transports nucleosynthesis products and allows the surface to rotate slower than the core. In addition, angular momentum removal by winds amplifies surface braking on the main sequence. Comparison of the surface composition of O7-8 giant stars with a sample of B stars with initial masses about four times smaller reveal that chemical enrichment scales with initial mass, as expected from theory. Conclusions. Although evolutionary models that include rotation face difficulties in explaining the chemical properties of O- and B-type stars at low metallicity, some of them can consistently account for the properties of main-sequence Galactic O stars in the mass range 25-40 M ⊙.
Instituto de Astrofísica de La Plata
description Context. Massive star evolution remains only partly constrained. In particular, the exact role of rotation has been questioned by puzzling properties of OB stars in the Magellanic Clouds. Aims. Our goal is to study the relation between surface chemical composition and rotational velocity, and to test predictions of evolutionary models including rotation. Methods. We have performed a spectroscopic analysis of a sample of fifteen Galactic O7-8 giant stars. This sample is homogeneous in terms of mass, metallicity and evolutionary state. It is made of stars with a wide range of projected rotational velocities. Results. We show that the sample stars are located on the second half of the main sequence, in a relatively narrow mass range (25-40 M⊙ ). Almost all stars with projected rotational velocities above 100 km s -1 have N/C ratios about ten times the initial value. Below 100 km s -1 a wide range of N/C values is observed. The relation between N/C and surface gravity is well reproduced by various sets of models. Some evolutionary models including rotation are also able to consistently explain slowly rotating, highly enriched stars. This is due to differential rotation which efficiently transports nucleosynthesis products and allows the surface to rotate slower than the core. In addition, angular momentum removal by winds amplifies surface braking on the main sequence. Comparison of the surface composition of O7-8 giant stars with a sample of B stars with initial masses about four times smaller reveal that chemical enrichment scales with initial mass, as expected from theory. Conclusions. Although evolutionary models that include rotation face difficulties in explaining the chemical properties of O- and B-type stars at low metallicity, some of them can consistently account for the properties of main-sequence Galactic O stars in the mass range 25-40 M ⊙.
publishDate 2017
dc.date.none.fl_str_mv 2017
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/10915/87119
url http://sedici.unlp.edu.ar/handle/10915/87119
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/10.1051/0004-6361/201629548
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
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reponame_str SEDICI (UNLP)
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repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
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