Outer boundary conditions for evolving cool white dwarfs

Autores
Rohrmann, Rene Daniel; Althaus, Leandro Gabriel; García Berro, Enrique; Corsico, Alejandro Hugo; Miller Bertolami, Marcelo Miguel
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Context. White dwarf evolution is essentially a gravothermal cooling process, which, for cool white dwarfs, depends on the treatment of the outer boundary conditions. Aims. We provide detailed outer boundary conditions that are appropriate to computing the evolution of cool white dwarfs by employing detailed nongray model atmospheres for pure hydrogen composition. We also explore the impact on the white dwarf cooling times of different assumptions for energy transfer in the atmosphere of cool white dwarfs. Methods. Detailed nongray model atmospheres were computed by considering nonideal effects in the gas equation of state and chemical equilibrium, collision-induced absorption from molecules, and the Lyman α quasi-molecular opacity. We explored the impact of outer boundary conditions provided by updated model atmospheres on the cooling times of 0.60 and 0.90 M white dwarf sequences. Results. Our results show that the use of detailed outer boundary conditions becomes relevant for effective temperatures lower than 5800 K for sequences with 0.60 M and 6100 K with 0.90 M . Detailed model atmospheres predict ages that are up to ≈10% shorter at log(L/L ) = −4 when compared with the ages derived using Eddington-like approximations at τRoss = 2/3. We also analyze the effects of various assumptions and physical processes that are relevant in the calculation of outer boundary conditions. In particular, we find that the Lyα red wing absorption does not substantially affect the evolution of white dwarfs. Conclusions. White dwarf cooling timescales are sensitive to the surface boundary conditions for Teff <∼ 6000 K. Interestingly enough, nongray effects have few consequences on these cooling times at observable luminosities. In fact, collision-induced absorption processes, which significantly affect the spectra and colors of old white dwarfs with hydrogen-rich atmospheres, have no noticeable effects on their cooling rates, except throughout the Rosseland mean opacity
Fil: Rohrmann, Rene Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina
Fil: Althaus, Leandro Gabriel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina
Fil: García Berro, Enrique. Universidad Politécnica de Catalunya; España
Fil: Corsico, Alejandro Hugo. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. 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: Miller Bertolami, Marcelo Miguel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. 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
Materia
Evolution of stars
Interior stars
White dwarfs
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:11336/42611
Acceder
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network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Outer boundary conditions for evolving cool white dwarfsRohrmann, Rene DanielAlthaus, Leandro GabrielGarcía Berro, EnriqueCorsico, Alejandro HugoMiller Bertolami, Marcelo MiguelEvolution of starsInterior starsWhite dwarfshttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Context. White dwarf evolution is essentially a gravothermal cooling process, which, for cool white dwarfs, depends on the treatment of the outer boundary conditions. Aims. We provide detailed outer boundary conditions that are appropriate to computing the evolution of cool white dwarfs by employing detailed nongray model atmospheres for pure hydrogen composition. We also explore the impact on the white dwarf cooling times of different assumptions for energy transfer in the atmosphere of cool white dwarfs. Methods. Detailed nongray model atmospheres were computed by considering nonideal effects in the gas equation of state and chemical equilibrium, collision-induced absorption from molecules, and the Lyman α quasi-molecular opacity. We explored the impact of outer boundary conditions provided by updated model atmospheres on the cooling times of 0.60 and 0.90 M white dwarf sequences. Results. Our results show that the use of detailed outer boundary conditions becomes relevant for effective temperatures lower than 5800 K for sequences with 0.60 M and 6100 K with 0.90 M . Detailed model atmospheres predict ages that are up to ≈10% shorter at log(L/L ) = −4 when compared with the ages derived using Eddington-like approximations at τRoss = 2/3. We also analyze the effects of various assumptions and physical processes that are relevant in the calculation of outer boundary conditions. In particular, we find that the Lyα red wing absorption does not substantially affect the evolution of white dwarfs. Conclusions. White dwarf cooling timescales are sensitive to the surface boundary conditions for Teff <∼ 6000 K. Interestingly enough, nongray effects have few consequences on these cooling times at observable luminosities. In fact, collision-induced absorption processes, which significantly affect the spectra and colors of old white dwarfs with hydrogen-rich atmospheres, have no noticeable effects on their cooling rates, except throughout the Rosseland mean opacityFil: Rohrmann, Rene Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Althaus, Leandro Gabriel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: García Berro, Enrique. Universidad Politécnica de Catalunya; EspañaFil: Corsico, Alejandro Hugo. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. 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: Miller Bertolami, Marcelo Miguel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. 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; ArgentinaEDP Sciences2012-10info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/42611Rohrmann, Rene Daniel; Althaus, Leandro Gabriel; García Berro, Enrique; Corsico, Alejandro Hugo; Miller Bertolami, Marcelo Miguel; Outer boundary conditions for evolving cool white dwarfs; EDP Sciences; Astronomy and Astrophysics; 546; 10-2012; A1190004-6361CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201219292info:eu-repo/semantics/altIdentifier/url/http://www.aanda.org/articles/aa/abs/2012/10/aa19292-12/aa19292-12.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 Técnicas2025-10-22T11:46:43Zoai:ri.conicet.gov.ar:11336/42611instacron: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 11:46:44.212CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Outer boundary conditions for evolving cool white dwarfs
title Outer boundary conditions for evolving cool white dwarfs
spellingShingle Outer boundary conditions for evolving cool white dwarfs
Rohrmann, Rene Daniel
Evolution of stars
Interior stars
White dwarfs
title_short Outer boundary conditions for evolving cool white dwarfs
title_full Outer boundary conditions for evolving cool white dwarfs
title_fullStr Outer boundary conditions for evolving cool white dwarfs
title_full_unstemmed Outer boundary conditions for evolving cool white dwarfs
title_sort Outer boundary conditions for evolving cool white dwarfs
dc.creator.none.fl_str_mv Rohrmann, Rene Daniel
Althaus, Leandro Gabriel
García Berro, Enrique
Corsico, Alejandro Hugo
Miller Bertolami, Marcelo Miguel
author Rohrmann, Rene Daniel
author_facet Rohrmann, Rene Daniel
Althaus, Leandro Gabriel
García Berro, Enrique
Corsico, Alejandro Hugo
Miller Bertolami, Marcelo Miguel
author_role author
author2 Althaus, Leandro Gabriel
García Berro, Enrique
Corsico, Alejandro Hugo
Miller Bertolami, Marcelo Miguel
author2_role author
author
author
author
dc.subject.none.fl_str_mv Evolution of stars
Interior stars
White dwarfs
topic Evolution of stars
Interior stars
White dwarfs
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. White dwarf evolution is essentially a gravothermal cooling process, which, for cool white dwarfs, depends on the treatment of the outer boundary conditions. Aims. We provide detailed outer boundary conditions that are appropriate to computing the evolution of cool white dwarfs by employing detailed nongray model atmospheres for pure hydrogen composition. We also explore the impact on the white dwarf cooling times of different assumptions for energy transfer in the atmosphere of cool white dwarfs. Methods. Detailed nongray model atmospheres were computed by considering nonideal effects in the gas equation of state and chemical equilibrium, collision-induced absorption from molecules, and the Lyman α quasi-molecular opacity. We explored the impact of outer boundary conditions provided by updated model atmospheres on the cooling times of 0.60 and 0.90 M white dwarf sequences. Results. Our results show that the use of detailed outer boundary conditions becomes relevant for effective temperatures lower than 5800 K for sequences with 0.60 M and 6100 K with 0.90 M . Detailed model atmospheres predict ages that are up to ≈10% shorter at log(L/L ) = −4 when compared with the ages derived using Eddington-like approximations at τRoss = 2/3. We also analyze the effects of various assumptions and physical processes that are relevant in the calculation of outer boundary conditions. In particular, we find that the Lyα red wing absorption does not substantially affect the evolution of white dwarfs. Conclusions. White dwarf cooling timescales are sensitive to the surface boundary conditions for Teff <∼ 6000 K. Interestingly enough, nongray effects have few consequences on these cooling times at observable luminosities. In fact, collision-induced absorption processes, which significantly affect the spectra and colors of old white dwarfs with hydrogen-rich atmospheres, have no noticeable effects on their cooling rates, except throughout the Rosseland mean opacity
Fil: Rohrmann, Rene Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina
Fil: Althaus, Leandro Gabriel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina
Fil: García Berro, Enrique. Universidad Politécnica de Catalunya; España
Fil: Corsico, Alejandro Hugo. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. 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: Miller Bertolami, Marcelo Miguel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. 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
description Context. White dwarf evolution is essentially a gravothermal cooling process, which, for cool white dwarfs, depends on the treatment of the outer boundary conditions. Aims. We provide detailed outer boundary conditions that are appropriate to computing the evolution of cool white dwarfs by employing detailed nongray model atmospheres for pure hydrogen composition. We also explore the impact on the white dwarf cooling times of different assumptions for energy transfer in the atmosphere of cool white dwarfs. Methods. Detailed nongray model atmospheres were computed by considering nonideal effects in the gas equation of state and chemical equilibrium, collision-induced absorption from molecules, and the Lyman α quasi-molecular opacity. We explored the impact of outer boundary conditions provided by updated model atmospheres on the cooling times of 0.60 and 0.90 M white dwarf sequences. Results. Our results show that the use of detailed outer boundary conditions becomes relevant for effective temperatures lower than 5800 K for sequences with 0.60 M and 6100 K with 0.90 M . Detailed model atmospheres predict ages that are up to ≈10% shorter at log(L/L ) = −4 when compared with the ages derived using Eddington-like approximations at τRoss = 2/3. We also analyze the effects of various assumptions and physical processes that are relevant in the calculation of outer boundary conditions. In particular, we find that the Lyα red wing absorption does not substantially affect the evolution of white dwarfs. Conclusions. White dwarf cooling timescales are sensitive to the surface boundary conditions for Teff <∼ 6000 K. Interestingly enough, nongray effects have few consequences on these cooling times at observable luminosities. In fact, collision-induced absorption processes, which significantly affect the spectra and colors of old white dwarfs with hydrogen-rich atmospheres, have no noticeable effects on their cooling rates, except throughout the Rosseland mean opacity
publishDate 2012
dc.date.none.fl_str_mv 2012-10
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/11336/42611
Rohrmann, Rene Daniel; Althaus, Leandro Gabriel; García Berro, Enrique; Corsico, Alejandro Hugo; Miller Bertolami, Marcelo Miguel; Outer boundary conditions for evolving cool white dwarfs; EDP Sciences; Astronomy and Astrophysics; 546; 10-2012; A119
0004-6361
CONICET Digital
CONICET
url http://hdl.handle.net/11336/42611
identifier_str_mv Rohrmann, Rene Daniel; Althaus, Leandro Gabriel; García Berro, Enrique; Corsico, Alejandro Hugo; Miller Bertolami, Marcelo Miguel; Outer boundary conditions for evolving cool white dwarfs; EDP Sciences; Astronomy and Astrophysics; 546; 10-2012; A119
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/10.1051/0004-6361/201219292
info:eu-repo/semantics/altIdentifier/url/http://www.aanda.org/articles/aa/abs/2012/10/aa19292-12/aa19292-12.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
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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