Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks

Autores
Cochetti, Yanina Roxana; Arcos, Camilo; Kanaan, S.; Meilland, A.; Cidale, Lydia Sonia; Cure, M.
Año de publicación
2019
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Context. Be stars are rapid rotators surrounded by a gaseous disk envelope whose origin is still under debate. This envelope is responsible for observed emission lines and large infrared excess. Aims. To progress in the understanding of the physical processes involved in the disk formation, we estimate the disk parameters for a sample of Be stars and search for correlations between these parameters and stellar properties. Methods. We performed spectro-interferometric observations of 26 Be stars in the region of the Brγ line to study the kinematical properties of their disks through the Doppler effect. Observations were performed at the Paranal observatory with the VLTI/AMBER interferometer. This instrument provides high spectral (R ' 12 000) and high spatial (θmin = 4 mas) resolutions. Results. We modeled 18 Be stars with emission in the Brγ line. The disk kinematic is described by a quasi-Keplerian rotation law, with the exception of HD 28497 that presents a one-arm density-wave structure. Using a combined sample, we derived a mean value for the velocity ratio V/Vc = 0.75 (where Vc is the critical velocity), and found that rotation axes are probably randomly distributed in the sky. Disk sizes in the line component model are in the range of 2–13 stellar radii and do not correlate with the effective temperature or spectral type. However, we found that the maximum size of a stable disk correlates with the rotation velocity at the inner part of the disk and the stellar mass. Conclusions. We found that, on average, the Be stars of our combined sample do not rotate at their critical velocity. However, the centrifugal force and mass of the star defines an upper limit size for a stable disk configuration. For a given rotation, high-mass Be stars tend to have more compact disks than their low-mass counterparts. It would be interesting to follow up the evolution of the disk size in variable stars to better understand the formation and dissipation processes of their circumstellar disks.
Fil: Cochetti, Yanina Roxana. 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. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina
Fil: Arcos, Camilo. Universidad de Valparaíso; Chile
Fil: Kanaan, S.. Universidad de Valparaíso; Chile
Fil: Meilland, A.. Université Côte d’Azur; Francia
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. Universidad de Valparaíso; Chile
Fil: Cure, M.. Universidad de Valparaíso; Chile
Materia
techniques: interferometric
techniques: high angular resolution
stars: winds, outflows
stars: emission-line, Be
stars: general
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:11336/121463
Acceder
id CONICETDig_df5352167f517eede716928bebb96472
oai_identifier_str oai:ri.conicet.gov.ar:11336/121463
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disksCochetti, Yanina RoxanaArcos, CamiloKanaan, S.Meilland, A.Cidale, Lydia SoniaCure, M.techniques: interferometrictechniques: high angular resolutionstars: winds, outflowsstars: emission-line, Bestars: generalhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Context. Be stars are rapid rotators surrounded by a gaseous disk envelope whose origin is still under debate. This envelope is responsible for observed emission lines and large infrared excess. Aims. To progress in the understanding of the physical processes involved in the disk formation, we estimate the disk parameters for a sample of Be stars and search for correlations between these parameters and stellar properties. Methods. We performed spectro-interferometric observations of 26 Be stars in the region of the Brγ line to study the kinematical properties of their disks through the Doppler effect. Observations were performed at the Paranal observatory with the VLTI/AMBER interferometer. This instrument provides high spectral (R ' 12 000) and high spatial (θmin = 4 mas) resolutions. Results. We modeled 18 Be stars with emission in the Brγ line. The disk kinematic is described by a quasi-Keplerian rotation law, with the exception of HD 28497 that presents a one-arm density-wave structure. Using a combined sample, we derived a mean value for the velocity ratio V/Vc = 0.75 (where Vc is the critical velocity), and found that rotation axes are probably randomly distributed in the sky. Disk sizes in the line component model are in the range of 2–13 stellar radii and do not correlate with the effective temperature or spectral type. However, we found that the maximum size of a stable disk correlates with the rotation velocity at the inner part of the disk and the stellar mass. Conclusions. We found that, on average, the Be stars of our combined sample do not rotate at their critical velocity. However, the centrifugal force and mass of the star defines an upper limit size for a stable disk configuration. For a given rotation, high-mass Be stars tend to have more compact disks than their low-mass counterparts. It would be interesting to follow up the evolution of the disk size in variable stars to better understand the formation and dissipation processes of their circumstellar disks.Fil: Cochetti, Yanina Roxana. 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. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Arcos, Camilo. Universidad de Valparaíso; ChileFil: Kanaan, S.. Universidad de Valparaíso; ChileFil: Meilland, A.. Université Côte d’Azur; FranciaFil: 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. Universidad de Valparaíso; ChileFil: Cure, M.. Universidad de Valparaíso; ChileEDP Sciences2019-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/121463Cochetti, Yanina Roxana; Arcos, Camilo; Kanaan, S.; Meilland, A.; Cidale, Lydia Sonia; et al.; Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks; EDP Sciences; Astronomy and Astrophysics; 621; A123; 1-2019; 1-290004-6361CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1811.11055info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201833551info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/full_html/2019/01/aa33551-18/aa33551-18.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 Técnicas2025-10-22T11:35:16Zoai:ri.conicet.gov.ar:11336/121463instacron: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:34982025-10-22 11:35:16.974CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks
title Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks
spellingShingle Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks
Cochetti, Yanina Roxana
techniques: interferometric
techniques: high angular resolution
stars: winds, outflows
stars: emission-line, Be
stars: general
title_short Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks
title_full Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks
title_fullStr Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks
title_full_unstemmed Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks
title_sort Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks
dc.creator.none.fl_str_mv Cochetti, Yanina Roxana
Arcos, Camilo
Kanaan, S.
Meilland, A.
Cidale, Lydia Sonia
Cure, M.
author Cochetti, Yanina Roxana
author_facet Cochetti, Yanina Roxana
Arcos, Camilo
Kanaan, S.
Meilland, A.
Cidale, Lydia Sonia
Cure, M.
author_role author
author2 Arcos, Camilo
Kanaan, S.
Meilland, A.
Cidale, Lydia Sonia
Cure, M.
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv techniques: interferometric
techniques: high angular resolution
stars: winds, outflows
stars: emission-line, Be
stars: general
topic techniques: interferometric
techniques: high angular resolution
stars: winds, outflows
stars: emission-line, Be
stars: general
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. Be stars are rapid rotators surrounded by a gaseous disk envelope whose origin is still under debate. This envelope is responsible for observed emission lines and large infrared excess. Aims. To progress in the understanding of the physical processes involved in the disk formation, we estimate the disk parameters for a sample of Be stars and search for correlations between these parameters and stellar properties. Methods. We performed spectro-interferometric observations of 26 Be stars in the region of the Brγ line to study the kinematical properties of their disks through the Doppler effect. Observations were performed at the Paranal observatory with the VLTI/AMBER interferometer. This instrument provides high spectral (R ' 12 000) and high spatial (θmin = 4 mas) resolutions. Results. We modeled 18 Be stars with emission in the Brγ line. The disk kinematic is described by a quasi-Keplerian rotation law, with the exception of HD 28497 that presents a one-arm density-wave structure. Using a combined sample, we derived a mean value for the velocity ratio V/Vc = 0.75 (where Vc is the critical velocity), and found that rotation axes are probably randomly distributed in the sky. Disk sizes in the line component model are in the range of 2–13 stellar radii and do not correlate with the effective temperature or spectral type. However, we found that the maximum size of a stable disk correlates with the rotation velocity at the inner part of the disk and the stellar mass. Conclusions. We found that, on average, the Be stars of our combined sample do not rotate at their critical velocity. However, the centrifugal force and mass of the star defines an upper limit size for a stable disk configuration. For a given rotation, high-mass Be stars tend to have more compact disks than their low-mass counterparts. It would be interesting to follow up the evolution of the disk size in variable stars to better understand the formation and dissipation processes of their circumstellar disks.
Fil: Cochetti, Yanina Roxana. 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. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina
Fil: Arcos, Camilo. Universidad de Valparaíso; Chile
Fil: Kanaan, S.. Universidad de Valparaíso; Chile
Fil: Meilland, A.. Université Côte d’Azur; Francia
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. Universidad de Valparaíso; Chile
Fil: Cure, M.. Universidad de Valparaíso; Chile
description Context. Be stars are rapid rotators surrounded by a gaseous disk envelope whose origin is still under debate. This envelope is responsible for observed emission lines and large infrared excess. Aims. To progress in the understanding of the physical processes involved in the disk formation, we estimate the disk parameters for a sample of Be stars and search for correlations between these parameters and stellar properties. Methods. We performed spectro-interferometric observations of 26 Be stars in the region of the Brγ line to study the kinematical properties of their disks through the Doppler effect. Observations were performed at the Paranal observatory with the VLTI/AMBER interferometer. This instrument provides high spectral (R ' 12 000) and high spatial (θmin = 4 mas) resolutions. Results. We modeled 18 Be stars with emission in the Brγ line. The disk kinematic is described by a quasi-Keplerian rotation law, with the exception of HD 28497 that presents a one-arm density-wave structure. Using a combined sample, we derived a mean value for the velocity ratio V/Vc = 0.75 (where Vc is the critical velocity), and found that rotation axes are probably randomly distributed in the sky. Disk sizes in the line component model are in the range of 2–13 stellar radii and do not correlate with the effective temperature or spectral type. However, we found that the maximum size of a stable disk correlates with the rotation velocity at the inner part of the disk and the stellar mass. Conclusions. We found that, on average, the Be stars of our combined sample do not rotate at their critical velocity. However, the centrifugal force and mass of the star defines an upper limit size for a stable disk configuration. For a given rotation, high-mass Be stars tend to have more compact disks than their low-mass counterparts. It would be interesting to follow up the evolution of the disk size in variable stars to better understand the formation and dissipation processes of their circumstellar disks.
publishDate 2019
dc.date.none.fl_str_mv 2019-01
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/11336/121463
Cochetti, Yanina Roxana; Arcos, Camilo; Kanaan, S.; Meilland, A.; Cidale, Lydia Sonia; et al.; Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks; EDP Sciences; Astronomy and Astrophysics; 621; A123; 1-2019; 1-29
0004-6361
CONICET Digital
CONICET
url http://hdl.handle.net/11336/121463
identifier_str_mv Cochetti, Yanina Roxana; Arcos, Camilo; Kanaan, S.; Meilland, A.; Cidale, Lydia Sonia; et al.; Spectro-interferometric observations of a sample of Be stars: Setting limits to the geometry and kinematics of stable Be disks; EDP Sciences; Astronomy and Astrophysics; 621; A123; 1-2019; 1-29
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/url/https://arxiv.org/abs/1811.11055
info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201833551
info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/full_html/2019/01/aa33551-18/aa33551-18.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
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 12.982451

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