Be star disc characteristics near the central object

Autores
Zorec, J.; Arias, María Laura; Cidale, Lydia Sonia; Ringuelet, Adela Emilia
Año de publicación
2007
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Context. A recent analysis of visual Fell emission lines of 17 classic Be stars using the self-absorption curve (SAC) method revealed that these lines are optically thick and that they form in circumstellar disc (CD) regions within two stellar radii from the central star on average. Aims. The aim of this paper is to study the physical characteristics of CD regions situated close to the central star. Methods. We used the Fell emission line optical depths derived for a sample of the above mentioned classic Be stars that are seen either nearly pole-on or equator-on. The disc properties sought are then inferred by reproducing the average pole-on and equator-on Fen line optical depths using simple CD models with different density and temperature distributions. Results. We found that the CD regions near the star, which account for the average Fe II line opacities obtained with the SAC method, have semi-height scales perpendicular to the equatorial plane h ≳ 0.5Ro and particle density distribution laws N(R) = No(Ro/R)n with n l∼ 1 at R ≲ 3Ro (Ro is the stellar radius; No is the particle density at R = Ro). Multi-scattering Monte Carlo simulations show that CD with particle density distributions N ∼ R-n, where n depends on the distance R and n ∼ 0.5 near the star, might account for the near-UV spectroplorarimetry of Be stars. CD with enhanced scale heights could explain the [Hα, E(J - L)] correlation as they may produce about the same Hα line emission, but larger IR flux excesses than thin discs. The enlarged CD scale heights do not contradict the existing interferometric measurements and should enable us to treat more consistently Balmer line emission formation in Be stars.
Fil: Zorec, J.. Universite Pierre et Marie Curie; Francia
Fil: Arias, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina
Fil: Cidale, Lydia Sonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina
Fil: Ringuelet, Adela Emilia. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Materia
LINE: FORMATION
POLARIZATION
STARS: CIRCUMSTELLAR MATTER
STARS: EMISSION-LINE, BE
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/38181
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/38181
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Be star disc characteristics near the central objectZorec, J.Arias, María LauraCidale, Lydia SoniaRinguelet, Adela EmiliaLINE: FORMATIONPOLARIZATIONSTARS: CIRCUMSTELLAR MATTERSTARS: EMISSION-LINE, BEhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Context. A recent analysis of visual Fell emission lines of 17 classic Be stars using the self-absorption curve (SAC) method revealed that these lines are optically thick and that they form in circumstellar disc (CD) regions within two stellar radii from the central star on average. Aims. The aim of this paper is to study the physical characteristics of CD regions situated close to the central star. Methods. We used the Fell emission line optical depths derived for a sample of the above mentioned classic Be stars that are seen either nearly pole-on or equator-on. The disc properties sought are then inferred by reproducing the average pole-on and equator-on Fen line optical depths using simple CD models with different density and temperature distributions. Results. We found that the CD regions near the star, which account for the average Fe II line opacities obtained with the SAC method, have semi-height scales perpendicular to the equatorial plane h ≳ 0.5Ro and particle density distribution laws N(R) = No(Ro/R)n with n l∼ 1 at R ≲ 3Ro (Ro is the stellar radius; No is the particle density at R = Ro). Multi-scattering Monte Carlo simulations show that CD with particle density distributions N ∼ R-n, where n depends on the distance R and n ∼ 0.5 near the star, might account for the near-UV spectroplorarimetry of Be stars. CD with enhanced scale heights could explain the [Hα, E(J - L)] correlation as they may produce about the same Hα line emission, but larger IR flux excesses than thin discs. The enlarged CD scale heights do not contradict the existing interferometric measurements and should enable us to treat more consistently Balmer line emission formation in Be stars.Fil: Zorec, J.. Universite Pierre et Marie Curie; FranciaFil: Arias, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Cidale, Lydia Sonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Ringuelet, Adela Emilia. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaEDP Sciences2007-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/38181Zorec, J.; Arias, María Laura; Cidale, Lydia Sonia; Ringuelet, Adela Emilia; Be star disc characteristics near the central object; EDP Sciences; Astronomy and Astrophysics; 470; 1; 7-2007; 239-2470004-6361CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:20066615info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/abs/2007/28/aa6615-06/aa6615-06.htmlinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:06:28Zoai:ri.conicet.gov.ar:11336/38181instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 10:06:28.654CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Be star disc characteristics near the central object
title Be star disc characteristics near the central object
spellingShingle Be star disc characteristics near the central object
Zorec, J.
LINE: FORMATION
POLARIZATION
STARS: CIRCUMSTELLAR MATTER
STARS: EMISSION-LINE, BE
title_short Be star disc characteristics near the central object
title_full Be star disc characteristics near the central object
title_fullStr Be star disc characteristics near the central object
title_full_unstemmed Be star disc characteristics near the central object
title_sort Be star disc characteristics near the central object
dc.creator.none.fl_str_mv Zorec, J.
Arias, María Laura
Cidale, Lydia Sonia
Ringuelet, Adela Emilia
author Zorec, J.
author_facet Zorec, J.
Arias, María Laura
Cidale, Lydia Sonia
Ringuelet, Adela Emilia
author_role author
author2 Arias, María Laura
Cidale, Lydia Sonia
Ringuelet, Adela Emilia
author2_role author
author
author
dc.subject.none.fl_str_mv LINE: FORMATION
POLARIZATION
STARS: CIRCUMSTELLAR MATTER
STARS: EMISSION-LINE, BE
topic LINE: FORMATION
POLARIZATION
STARS: CIRCUMSTELLAR MATTER
STARS: EMISSION-LINE, BE
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Context. A recent analysis of visual Fell emission lines of 17 classic Be stars using the self-absorption curve (SAC) method revealed that these lines are optically thick and that they form in circumstellar disc (CD) regions within two stellar radii from the central star on average. Aims. The aim of this paper is to study the physical characteristics of CD regions situated close to the central star. Methods. We used the Fell emission line optical depths derived for a sample of the above mentioned classic Be stars that are seen either nearly pole-on or equator-on. The disc properties sought are then inferred by reproducing the average pole-on and equator-on Fen line optical depths using simple CD models with different density and temperature distributions. Results. We found that the CD regions near the star, which account for the average Fe II line opacities obtained with the SAC method, have semi-height scales perpendicular to the equatorial plane h ≳ 0.5Ro and particle density distribution laws N(R) = No(Ro/R)n with n l∼ 1 at R ≲ 3Ro (Ro is the stellar radius; No is the particle density at R = Ro). Multi-scattering Monte Carlo simulations show that CD with particle density distributions N ∼ R-n, where n depends on the distance R and n ∼ 0.5 near the star, might account for the near-UV spectroplorarimetry of Be stars. CD with enhanced scale heights could explain the [Hα, E(J - L)] correlation as they may produce about the same Hα line emission, but larger IR flux excesses than thin discs. The enlarged CD scale heights do not contradict the existing interferometric measurements and should enable us to treat more consistently Balmer line emission formation in Be stars.
Fil: Zorec, J.. Universite Pierre et Marie Curie; Francia
Fil: Arias, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina
Fil: Cidale, Lydia Sonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina
Fil: Ringuelet, Adela Emilia. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
description Context. A recent analysis of visual Fell emission lines of 17 classic Be stars using the self-absorption curve (SAC) method revealed that these lines are optically thick and that they form in circumstellar disc (CD) regions within two stellar radii from the central star on average. Aims. The aim of this paper is to study the physical characteristics of CD regions situated close to the central star. Methods. We used the Fell emission line optical depths derived for a sample of the above mentioned classic Be stars that are seen either nearly pole-on or equator-on. The disc properties sought are then inferred by reproducing the average pole-on and equator-on Fen line optical depths using simple CD models with different density and temperature distributions. Results. We found that the CD regions near the star, which account for the average Fe II line opacities obtained with the SAC method, have semi-height scales perpendicular to the equatorial plane h ≳ 0.5Ro and particle density distribution laws N(R) = No(Ro/R)n with n l∼ 1 at R ≲ 3Ro (Ro is the stellar radius; No is the particle density at R = Ro). Multi-scattering Monte Carlo simulations show that CD with particle density distributions N ∼ R-n, where n depends on the distance R and n ∼ 0.5 near the star, might account for the near-UV spectroplorarimetry of Be stars. CD with enhanced scale heights could explain the [Hα, E(J - L)] correlation as they may produce about the same Hα line emission, but larger IR flux excesses than thin discs. The enlarged CD scale heights do not contradict the existing interferometric measurements and should enable us to treat more consistently Balmer line emission formation in Be stars.
publishDate 2007
dc.date.none.fl_str_mv 2007-07
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
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://hdl.handle.net/11336/38181
Zorec, J.; Arias, María Laura; Cidale, Lydia Sonia; Ringuelet, Adela Emilia; Be star disc characteristics near the central object; EDP Sciences; Astronomy and Astrophysics; 470; 1; 7-2007; 239-247
0004-6361
CONICET Digital
CONICET
url http://hdl.handle.net/11336/38181
identifier_str_mv Zorec, J.; Arias, María Laura; Cidale, Lydia Sonia; Ringuelet, Adela Emilia; Be star disc characteristics near the central object; EDP Sciences; Astronomy and Astrophysics; 470; 1; 7-2007; 239-247
0004-6361
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:20066615
info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/abs/2007/28/aa6615-06/aa6615-06.html
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv EDP Sciences
publisher.none.fl_str_mv EDP Sciences
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.070432

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