Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes

Autores
Vallverdú, Rodolfo Enrique; Cidale, Lydia Sonia; Rohrmann, René D.; Ringuelet, Adela Emilia
Año de publicación
2014
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We analyze the influence of magnetic pressure effects on the atmospheric structure of B peculiar type stars, as well as, on the emergent He I line profiles and absolute visual magnitudes. We consider a photosphere in local thermodynamic and hydrostatic equilibrium. The hydrostatic equilibrium equation is modified to include the Lorentz force. Atomic occupational numbers are computed in LTE considering non-ideal effects in the gas equation of state. We depict the influence of a magnetic field on local He I line profiles and discuss the effects of the helium abundance in magnetic B-type stars. The Lorentz force might explain local variations up to 7 % in the equivalent width of helium lines, while local enhancements of He chemical abundances would produce larger changes. To analyze the line variations in real stars we computed the net contribution of a bipolar magnetic field over the stellar disk. The resulting disk-averaged magnetic field predicts variations with the rotation phase up to 2–3 % in the line EWs for a dipolar magnetic field of 1000 G.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
Materia
Astronomía
Stars: magnetic field
Stars: chemically peculiar
Stars: early-type
Stars: atmospheres
Line: profiles
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/137673
Acceder
id SEDICI_2409bfbc626135f1bf4ffa686356f865
oai_identifier_str oai:sedici.unlp.edu.ar:10915/137673
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudesVallverdú, Rodolfo EnriqueCidale, Lydia SoniaRohrmann, René D.Ringuelet, Adela EmiliaAstronomíaStars: magnetic fieldStars: chemically peculiarStars: early-typeStars: atmospheresLine: profilesWe analyze the influence of magnetic pressure effects on the atmospheric structure of B peculiar type stars, as well as, on the emergent He I line profiles and absolute visual magnitudes. We consider a photosphere in local thermodynamic and hydrostatic equilibrium. The hydrostatic equilibrium equation is modified to include the Lorentz force. Atomic occupational numbers are computed in LTE considering non-ideal effects in the gas equation of state. We depict the influence of a magnetic field on local He I line profiles and discuss the effects of the helium abundance in magnetic B-type stars. The Lorentz force might explain local variations up to 7 % in the equivalent width of helium lines, while local enhancements of He chemical abundances would produce larger changes. To analyze the line variations in real stars we computed the net contribution of a bipolar magnetic field over the stellar disk. The resulting disk-averaged magnetic field predicts variations with the rotation phase up to 2–3 % in the line EWs for a dipolar magnetic field of 1000 G.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plata2014-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf95-102http://sedici.unlp.edu.ar/handle/10915/137673enginfo:eu-repo/semantics/altIdentifier/issn/0004-640Xinfo:eu-repo/semantics/altIdentifier/issn/1572-946Xinfo:eu-repo/semantics/altIdentifier/doi/10.1007/s10509-014-1886-yinfo:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-10-22T17:12:57Zoai:sedici.unlp.edu.ar:10915/137673Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-10-22 17:12:57.447SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes
title Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes
spellingShingle Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes
Vallverdú, Rodolfo Enrique
Astronomía
Stars: magnetic field
Stars: chemically peculiar
Stars: early-type
Stars: atmospheres
Line: profiles
title_short Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes
title_full Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes
title_fullStr Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes
title_full_unstemmed Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes
title_sort Atmospheric models of He-peculiar stars: synthetic He I line profiles and absolute visual magnitudes
dc.creator.none.fl_str_mv Vallverdú, Rodolfo Enrique
Cidale, Lydia Sonia
Rohrmann, René D.
Ringuelet, Adela Emilia
author Vallverdú, Rodolfo Enrique
author_facet Vallverdú, Rodolfo Enrique
Cidale, Lydia Sonia
Rohrmann, René D.
Ringuelet, Adela Emilia
author_role author
author2 Cidale, Lydia Sonia
Rohrmann, René D.
Ringuelet, Adela Emilia
author2_role author
author
author
dc.subject.none.fl_str_mv Astronomía
Stars: magnetic field
Stars: chemically peculiar
Stars: early-type
Stars: atmospheres
Line: profiles
topic Astronomía
Stars: magnetic field
Stars: chemically peculiar
Stars: early-type
Stars: atmospheres
Line: profiles
dc.description.none.fl_txt_mv We analyze the influence of magnetic pressure effects on the atmospheric structure of B peculiar type stars, as well as, on the emergent He I line profiles and absolute visual magnitudes. We consider a photosphere in local thermodynamic and hydrostatic equilibrium. The hydrostatic equilibrium equation is modified to include the Lorentz force. Atomic occupational numbers are computed in LTE considering non-ideal effects in the gas equation of state. We depict the influence of a magnetic field on local He I line profiles and discuss the effects of the helium abundance in magnetic B-type stars. The Lorentz force might explain local variations up to 7 % in the equivalent width of helium lines, while local enhancements of He chemical abundances would produce larger changes. To analyze the line variations in real stars we computed the net contribution of a bipolar magnetic field over the stellar disk. The resulting disk-averaged magnetic field predicts variations with the rotation phase up to 2–3 % in the line EWs for a dipolar magnetic field of 1000 G.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
description We analyze the influence of magnetic pressure effects on the atmospheric structure of B peculiar type stars, as well as, on the emergent He I line profiles and absolute visual magnitudes. We consider a photosphere in local thermodynamic and hydrostatic equilibrium. The hydrostatic equilibrium equation is modified to include the Lorentz force. Atomic occupational numbers are computed in LTE considering non-ideal effects in the gas equation of state. We depict the influence of a magnetic field on local He I line profiles and discuss the effects of the helium abundance in magnetic B-type stars. The Lorentz force might explain local variations up to 7 % in the equivalent width of helium lines, while local enhancements of He chemical abundances would produce larger changes. To analyze the line variations in real stars we computed the net contribution of a bipolar magnetic field over the stellar disk. The resulting disk-averaged magnetic field predicts variations with the rotation phase up to 2–3 % in the line EWs for a dipolar magnetic field of 1000 G.
publishDate 2014
dc.date.none.fl_str_mv 2014-07
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/10915/137673
url http://sedici.unlp.edu.ar/handle/10915/137673
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0004-640X
info:eu-repo/semantics/altIdentifier/issn/1572-946X
info:eu-repo/semantics/altIdentifier/doi/10.1007/s10509-014-1886-y
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv application/pdf
95-102
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 12.982451

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