Modeling He-rich subdwarfs through the hot-flasher scenario
- Autores
- Miller Bertolami, Marcelo Miguel; Althaus, Leandro Gabriel; Unglaub, K.; Weiss, A.
- Año de publicación
- 2008
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- We present 1D numerical simulations aimed at studying the hot-flasher scenario for the formation of He-rich subdwarf stars. Sequences were calculated for a wide range of metallicities and physical assumptions, such as the stellar mass at the moment of the helium core flash. This allows us to study the two previously proposed flavors of the hot-flasher scenario ("deep" and "shallow" mixing cases) and to identify a third transition type. Our sequences are calculated by solving simultaneously the mixing and burning equations within a diffusive convection picture, and in the context of standard mixing length theory. We are able to follow chemical evolution during deep-mixing events in which hydrogen is burned violently, and therefore able to present a homogeneous set of abundances for different metallicities and varieties of hot-flashers. We extend the scope of our work by analyzing the effects of non-standard assumptions, such as the effect of chemical gradients, extra-mixing at convective boundaries, possible reduction in convective velocities, or the interplay between difussion and mass loss. Particular emphasis is placed on the predicted surface properties of the models. We find that the hot-flasher scenario is a viable explanation for the formation and surface properties of He-sdO stars. Our results also show that, during the early He-core burning stage, element diffusion may produce the transformation of (post hot-flasher) He-rich atmospheres into He-deficient ones. If this is so, then we find that He-sdO stars should be the progenitors of some of the hottest sdB stars.
Instituto de Astrofísica de La Plata
Facultad de Ciencias Astronómicas y Geofísicas - Materia
-
Ciencias Astronómicas
Stars: evolution
Stars: horizontal-branch
Stars: mass-loss
Stars: subdwarfs - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/84831
Ver los metadatos del registro completo
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Modeling He-rich subdwarfs through the hot-flasher scenarioMiller Bertolami, Marcelo MiguelAlthaus, Leandro GabrielUnglaub, K.Weiss, A.Ciencias AstronómicasStars: evolutionStars: horizontal-branchStars: mass-lossStars: subdwarfsWe present 1D numerical simulations aimed at studying the hot-flasher scenario for the formation of He-rich subdwarf stars. Sequences were calculated for a wide range of metallicities and physical assumptions, such as the stellar mass at the moment of the helium core flash. This allows us to study the two previously proposed flavors of the hot-flasher scenario ("deep" and "shallow" mixing cases) and to identify a third transition type. Our sequences are calculated by solving simultaneously the mixing and burning equations within a diffusive convection picture, and in the context of standard mixing length theory. We are able to follow chemical evolution during deep-mixing events in which hydrogen is burned violently, and therefore able to present a homogeneous set of abundances for different metallicities and varieties of hot-flashers. We extend the scope of our work by analyzing the effects of non-standard assumptions, such as the effect of chemical gradients, extra-mixing at convective boundaries, possible reduction in convective velocities, or the interplay between difussion and mass loss. Particular emphasis is placed on the predicted surface properties of the models. We find that the hot-flasher scenario is a viable explanation for the formation and surface properties of He-sdO stars. Our results also show that, during the early He-core burning stage, element diffusion may produce the transformation of (post hot-flasher) He-rich atmospheres into He-deficient ones. If this is so, then we find that He-sdO stars should be the progenitors of some of the hottest sdB stars.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísicas2008info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf253-265http://sedici.unlp.edu.ar/handle/10915/84831enginfo:eu-repo/semantics/altIdentifier/issn/0004-6361info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:200810373info: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:UNLP2025-09-29T11:16:11Zoai:sedici.unlp.edu.ar:10915/84831Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:16:11.395SEDICI (UNLP) - Universidad Nacional de La Platafalse |
dc.title.none.fl_str_mv |
Modeling He-rich subdwarfs through the hot-flasher scenario |
title |
Modeling He-rich subdwarfs through the hot-flasher scenario |
spellingShingle |
Modeling He-rich subdwarfs through the hot-flasher scenario Miller Bertolami, Marcelo Miguel Ciencias Astronómicas Stars: evolution Stars: horizontal-branch Stars: mass-loss Stars: subdwarfs |
title_short |
Modeling He-rich subdwarfs through the hot-flasher scenario |
title_full |
Modeling He-rich subdwarfs through the hot-flasher scenario |
title_fullStr |
Modeling He-rich subdwarfs through the hot-flasher scenario |
title_full_unstemmed |
Modeling He-rich subdwarfs through the hot-flasher scenario |
title_sort |
Modeling He-rich subdwarfs through the hot-flasher scenario |
dc.creator.none.fl_str_mv |
Miller Bertolami, Marcelo Miguel Althaus, Leandro Gabriel Unglaub, K. Weiss, A. |
author |
Miller Bertolami, Marcelo Miguel |
author_facet |
Miller Bertolami, Marcelo Miguel Althaus, Leandro Gabriel Unglaub, K. Weiss, A. |
author_role |
author |
author2 |
Althaus, Leandro Gabriel Unglaub, K. Weiss, A. |
author2_role |
author author author |
dc.subject.none.fl_str_mv |
Ciencias Astronómicas Stars: evolution Stars: horizontal-branch Stars: mass-loss Stars: subdwarfs |
topic |
Ciencias Astronómicas Stars: evolution Stars: horizontal-branch Stars: mass-loss Stars: subdwarfs |
dc.description.none.fl_txt_mv |
We present 1D numerical simulations aimed at studying the hot-flasher scenario for the formation of He-rich subdwarf stars. Sequences were calculated for a wide range of metallicities and physical assumptions, such as the stellar mass at the moment of the helium core flash. This allows us to study the two previously proposed flavors of the hot-flasher scenario ("deep" and "shallow" mixing cases) and to identify a third transition type. Our sequences are calculated by solving simultaneously the mixing and burning equations within a diffusive convection picture, and in the context of standard mixing length theory. We are able to follow chemical evolution during deep-mixing events in which hydrogen is burned violently, and therefore able to present a homogeneous set of abundances for different metallicities and varieties of hot-flashers. We extend the scope of our work by analyzing the effects of non-standard assumptions, such as the effect of chemical gradients, extra-mixing at convective boundaries, possible reduction in convective velocities, or the interplay between difussion and mass loss. Particular emphasis is placed on the predicted surface properties of the models. We find that the hot-flasher scenario is a viable explanation for the formation and surface properties of He-sdO stars. Our results also show that, during the early He-core burning stage, element diffusion may produce the transformation of (post hot-flasher) He-rich atmospheres into He-deficient ones. If this is so, then we find that He-sdO stars should be the progenitors of some of the hottest sdB stars. Instituto de Astrofísica de La Plata Facultad de Ciencias Astronómicas y Geofísicas |
description |
We present 1D numerical simulations aimed at studying the hot-flasher scenario for the formation of He-rich subdwarf stars. Sequences were calculated for a wide range of metallicities and physical assumptions, such as the stellar mass at the moment of the helium core flash. This allows us to study the two previously proposed flavors of the hot-flasher scenario ("deep" and "shallow" mixing cases) and to identify a third transition type. Our sequences are calculated by solving simultaneously the mixing and burning equations within a diffusive convection picture, and in the context of standard mixing length theory. We are able to follow chemical evolution during deep-mixing events in which hydrogen is burned violently, and therefore able to present a homogeneous set of abundances for different metallicities and varieties of hot-flashers. We extend the scope of our work by analyzing the effects of non-standard assumptions, such as the effect of chemical gradients, extra-mixing at convective boundaries, possible reduction in convective velocities, or the interplay between difussion and mass loss. Particular emphasis is placed on the predicted surface properties of the models. We find that the hot-flasher scenario is a viable explanation for the formation and surface properties of He-sdO stars. Our results also show that, during the early He-core burning stage, element diffusion may produce the transformation of (post hot-flasher) He-rich atmospheres into He-deficient ones. If this is so, then we find that He-sdO stars should be the progenitors of some of the hottest sdB stars. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008 |
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 |
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article |
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publishedVersion |
dc.identifier.none.fl_str_mv |
http://sedici.unlp.edu.ar/handle/10915/84831 |
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http://sedici.unlp.edu.ar/handle/10915/84831 |
dc.language.none.fl_str_mv |
eng |
language |
eng |
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info:eu-repo/semantics/altIdentifier/issn/0004-6361 info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:200810373 |
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) |
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openAccess |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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