Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars

Autores
Surlan, B.; Hamann, W. R.; Aret, A.; Kubát, J.; Oskinova, L. M.; Torres, Andrea Fabiana
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Context. Recent studies of O-type stars have demonstrated that discrepant mass-loss rates are obtained when different diagnostic methods are employed. Fitting the unsaturated UV resonance lines (e.g., P v) gives drastically lower values than obtained from the Hα emission. Wind inhomogeneity (so-called “clumping”) may be the main cause of this discrepancy. Aims. In a previous paper, we presented 3D Monte-Carlo calculations for the formation of scattering lines in a clumped stellar wind.In the present paper we select five O-type supergiants (from O4 to O7) and test whether the reported iscrepancies can be resolved this way. Methods. In the first step, the analyses started with simulating the observed spectra with Potsdam Wolf-Rayet (PoWR) non-LTE model atmospheres. The mass-loss rates are adjusted to fit to the observed Hα emission lines best. For the unsaturated UV resonance lines (i.e., P v) we then applied our 3D Monte-Carlo code, which can account for wind clumps of any optical depths (“macroclumping”), a non-void interclump medium, and a velocity dispersion inside the clumps. The ionization stratifications and underlying photospheric spectra were adopted from the PoWR models. The properties of the wind clumps were constrained by fitting the observed resonance line profiles. Results. Our results show that with the mass-loss rates that fit Hα (and other Balmer and He ii lines), the UV resonance lines (especially the unsaturated doublet of P v) can also be reproduced with no problem when macroclumping is taken into account. There is no need to artificially reduce the mass-loss rates or to assume a subsolar phosphorus abundance or an extremely high clumping factor, unlike what was claimed by other authors. These consistent mass-loss rates are lower by a factor of 1.3 to 2.6, compared to the mass-loss rate recipe from Vink et al. Conclusions. Macroclumping resolves the previously reported discrepancy between Hα and P v mass-loss diagnostics.
Fil: Surlan, B.. Astronomický Ústav, Akademie Ved ; República Checa. Matematicki Institut Sanu; Serbia
Fil: Hamann, W. R.. Universität Potsdam. Institut Für Physik Und Astronomie; Alemania
Fil: Aret, A.. Tartu Observatory; Estonia
Fil: Kubát, J.. Astronomický Ústav. Akademie Ved; República Checa
Fil: Oskinova, L. M.. Universität Potsdam. Institut Für Physik Und Astronomie; Alemania
Fil: Torres, Andrea Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Astrofísica de la Plata; Argentina
Materia
Winds
Outflows
Mass loss
Early type stars
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:11336/8581

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oai_identifier_str oai:ri.conicet.gov.ar:11336/8581
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type starsSurlan, B.Hamann, W. R.Aret, A.Kubát, J.Oskinova, L. M.Torres, Andrea FabianaWindsOutflowsMass lossEarly type starshttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Context. Recent studies of O-type stars have demonstrated that discrepant mass-loss rates are obtained when different diagnostic methods are employed. Fitting the unsaturated UV resonance lines (e.g., P v) gives drastically lower values than obtained from the Hα emission. Wind inhomogeneity (so-called “clumping”) may be the main cause of this discrepancy. Aims. In a previous paper, we presented 3D Monte-Carlo calculations for the formation of scattering lines in a clumped stellar wind.In the present paper we select five O-type supergiants (from O4 to O7) and test whether the reported iscrepancies can be resolved this way. Methods. In the first step, the analyses started with simulating the observed spectra with Potsdam Wolf-Rayet (PoWR) non-LTE model atmospheres. The mass-loss rates are adjusted to fit to the observed Hα emission lines best. For the unsaturated UV resonance lines (i.e., P v) we then applied our 3D Monte-Carlo code, which can account for wind clumps of any optical depths (“macroclumping”), a non-void interclump medium, and a velocity dispersion inside the clumps. The ionization stratifications and underlying photospheric spectra were adopted from the PoWR models. The properties of the wind clumps were constrained by fitting the observed resonance line profiles. Results. Our results show that with the mass-loss rates that fit Hα (and other Balmer and He ii lines), the UV resonance lines (especially the unsaturated doublet of P v) can also be reproduced with no problem when macroclumping is taken into account. There is no need to artificially reduce the mass-loss rates or to assume a subsolar phosphorus abundance or an extremely high clumping factor, unlike what was claimed by other authors. These consistent mass-loss rates are lower by a factor of 1.3 to 2.6, compared to the mass-loss rate recipe from Vink et al. Conclusions. Macroclumping resolves the previously reported discrepancy between Hα and P v mass-loss diagnostics.Fil: Surlan, B.. Astronomický Ústav, Akademie Ved ; República Checa. Matematicki Institut Sanu; SerbiaFil: Hamann, W. R.. Universität Potsdam. Institut Für Physik Und Astronomie; AlemaniaFil: Aret, A.. Tartu Observatory; EstoniaFil: Kubát, J.. Astronomický Ústav. Akademie Ved; República ChecaFil: Oskinova, L. M.. Universität Potsdam. Institut Für Physik Und Astronomie; AlemaniaFil: Torres, Andrea Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Astrofísica de la Plata; ArgentinaEdp Sciences2013-11info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/8581Surlan, B.; Hamann, W. R.; Aret, A.; Kubát, J.; Oskinova, L. M.; et al.; Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars; Edp Sciences; Astronomy And Astrophysics; 559; A130; 11-2013; 1-170004-6361enginfo:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201322390info:eu-repo/semantics/altIdentifier/url/http://www.aanda.org/articles/aa/abs/2013/11/aa22390-13/aa22390-13.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 Técnicas2025-09-29T10:25:27Zoai:ri.conicet.gov.ar:11336/8581instacron: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 10:25:27.643CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars
title Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars
spellingShingle Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars
Surlan, B.
Winds
Outflows
Mass loss
Early type stars
title_short Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars
title_full Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars
title_fullStr Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars
title_full_unstemmed Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars
title_sort Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars
dc.creator.none.fl_str_mv Surlan, B.
Hamann, W. R.
Aret, A.
Kubát, J.
Oskinova, L. M.
Torres, Andrea Fabiana
author Surlan, B.
author_facet Surlan, B.
Hamann, W. R.
Aret, A.
Kubát, J.
Oskinova, L. M.
Torres, Andrea Fabiana
author_role author
author2 Hamann, W. R.
Aret, A.
Kubát, J.
Oskinova, L. M.
Torres, Andrea Fabiana
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Winds
Outflows
Mass loss
Early type stars
topic Winds
Outflows
Mass loss
Early type stars
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. Recent studies of O-type stars have demonstrated that discrepant mass-loss rates are obtained when different diagnostic methods are employed. Fitting the unsaturated UV resonance lines (e.g., P v) gives drastically lower values than obtained from the Hα emission. Wind inhomogeneity (so-called “clumping”) may be the main cause of this discrepancy. Aims. In a previous paper, we presented 3D Monte-Carlo calculations for the formation of scattering lines in a clumped stellar wind.In the present paper we select five O-type supergiants (from O4 to O7) and test whether the reported iscrepancies can be resolved this way. Methods. In the first step, the analyses started with simulating the observed spectra with Potsdam Wolf-Rayet (PoWR) non-LTE model atmospheres. The mass-loss rates are adjusted to fit to the observed Hα emission lines best. For the unsaturated UV resonance lines (i.e., P v) we then applied our 3D Monte-Carlo code, which can account for wind clumps of any optical depths (“macroclumping”), a non-void interclump medium, and a velocity dispersion inside the clumps. The ionization stratifications and underlying photospheric spectra were adopted from the PoWR models. The properties of the wind clumps were constrained by fitting the observed resonance line profiles. Results. Our results show that with the mass-loss rates that fit Hα (and other Balmer and He ii lines), the UV resonance lines (especially the unsaturated doublet of P v) can also be reproduced with no problem when macroclumping is taken into account. There is no need to artificially reduce the mass-loss rates or to assume a subsolar phosphorus abundance or an extremely high clumping factor, unlike what was claimed by other authors. These consistent mass-loss rates are lower by a factor of 1.3 to 2.6, compared to the mass-loss rate recipe from Vink et al. Conclusions. Macroclumping resolves the previously reported discrepancy between Hα and P v mass-loss diagnostics.
Fil: Surlan, B.. Astronomický Ústav, Akademie Ved ; República Checa. Matematicki Institut Sanu; Serbia
Fil: Hamann, W. R.. Universität Potsdam. Institut Für Physik Und Astronomie; Alemania
Fil: Aret, A.. Tartu Observatory; Estonia
Fil: Kubát, J.. Astronomický Ústav. Akademie Ved; República Checa
Fil: Oskinova, L. M.. Universität Potsdam. Institut Für Physik Und Astronomie; Alemania
Fil: Torres, Andrea Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Astrofísica de la Plata; Argentina
description Context. Recent studies of O-type stars have demonstrated that discrepant mass-loss rates are obtained when different diagnostic methods are employed. Fitting the unsaturated UV resonance lines (e.g., P v) gives drastically lower values than obtained from the Hα emission. Wind inhomogeneity (so-called “clumping”) may be the main cause of this discrepancy. Aims. In a previous paper, we presented 3D Monte-Carlo calculations for the formation of scattering lines in a clumped stellar wind.In the present paper we select five O-type supergiants (from O4 to O7) and test whether the reported iscrepancies can be resolved this way. Methods. In the first step, the analyses started with simulating the observed spectra with Potsdam Wolf-Rayet (PoWR) non-LTE model atmospheres. The mass-loss rates are adjusted to fit to the observed Hα emission lines best. For the unsaturated UV resonance lines (i.e., P v) we then applied our 3D Monte-Carlo code, which can account for wind clumps of any optical depths (“macroclumping”), a non-void interclump medium, and a velocity dispersion inside the clumps. The ionization stratifications and underlying photospheric spectra were adopted from the PoWR models. The properties of the wind clumps were constrained by fitting the observed resonance line profiles. Results. Our results show that with the mass-loss rates that fit Hα (and other Balmer and He ii lines), the UV resonance lines (especially the unsaturated doublet of P v) can also be reproduced with no problem when macroclumping is taken into account. There is no need to artificially reduce the mass-loss rates or to assume a subsolar phosphorus abundance or an extremely high clumping factor, unlike what was claimed by other authors. These consistent mass-loss rates are lower by a factor of 1.3 to 2.6, compared to the mass-loss rate recipe from Vink et al. Conclusions. Macroclumping resolves the previously reported discrepancy between Hα and P v mass-loss diagnostics.
publishDate 2013
dc.date.none.fl_str_mv 2013-11
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/11336/8581
Surlan, B.; Hamann, W. R.; Aret, A.; Kubát, J.; Oskinova, L. M.; et al.; Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars; Edp Sciences; Astronomy And Astrophysics; 559; A130; 11-2013; 1-17
0004-6361
url http://hdl.handle.net/11336/8581
identifier_str_mv Surlan, B.; Hamann, W. R.; Aret, A.; Kubát, J.; Oskinova, L. M.; et al.; Macroclumping as solution of the discrepancy between Halpha and P V mass loss diagnostics for O-type stars; Edp Sciences; Astronomy And Astrophysics; 559; A130; 11-2013; 1-17
0004-6361
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201322390
info:eu-repo/semantics/altIdentifier/url/http://www.aanda.org/articles/aa/abs/2013/11/aa22390-13/aa22390-13.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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