Comparison of theoretical white dwarf cooling timescales.

Autores
Salaris, M.; Althaus, Leandro Gabriel; García-Berro, E.
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Context. An accurate assessment of white dwarf cooling times is paramount so that white dwarf cosmochronology of Galactic populations can be put on more solid grounds. This issue is particularly relevant in view of the enhanced observational capabilities provided by the next generation of extremely large telescopes, that will offer more avenues to use white dwarfs as probes of Galactic evolution and test-beds of fundamental physics.
Aims: We estimate for the first time the consistency of results obtained from independent evolutionary codes for white dwarf models with fixed mass and chemical stratification, when the same input physics is employed in the calculations.
Methods: We compute and compare cooling times obtained from two independent and widely used stellar evolution codes, BaSTI and LPCODE evolutionary codes, using exactly the same input physics for 0.55 M white dwarf models with both pure carbon and uniform carbon-oxygen (50/50 mass fractions) cores, and pure hydrogen layers with mass fraction qH = 10-4MWD on top of pure helium buffers of mass qHe = 10-2MWD.
Results: Using the same radiative and conductive opacities, photospheric boundary conditions, neutrino energy loss rates, and equation of state, cooling times from the two codes agree within ~2% at all luminosities, except when log (L/L) > -1.5 where differences up to ~8% do appear, because of the different thermal structures of the first white dwarf converged models at the beginning of the cooling sequence. This agreement is true for both pure carbon and uniform carbon-oxygen stratification core models, and also when the release of latent heat and carbon-oxygen phase separation are considered. We have also determined quantitatively and explained the effect of varying equation of state, low-temperature radiative opacities, and electron conduction opacities in our calculations,
Conclusions: We have assessed for the first time the maximum possible accuracy in the current estimates of white dwarf cooling times, resulting only from the different implementations of the stellar evolution equations and homogeneous input physics in two independent stellar evolution codes. This accuracy amounts to ~2% at luminosities lower than log (L/L) ~ -1.5. This difference is smaller than the uncertainties in cooling times attributable to the present uncertainties in the white dwarf chemical stratification. Finally, we extend the scope of our work by providing tabulations of our cooling sequences and the required input physics that can be used as a comparison test of cooling times obtained from other white dwarf evolutionary codes.
Fil: Salaris, M.. Astrophysics Research Institute. Liverpool John Moores University. Liverpool Science Park; Reino Unido;
Fil: Althaus, Leandro Gabriel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Grupo de Evolución Estelar y Pulsaciones; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Astrofisica la Plata; Argentina;
Fil: García-Berro, E.. Departament de Física Aplicada. Universitat Politècnica de Catalunya; Argentina; Institute for Space Studies of Catalonia; Argentina;
Materia
stars: interiors
stars: evolution 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:11336/632

id CONICETDig_c1b8c12db05f8dbbdbf14306baa84942
oai_identifier_str oai:ri.conicet.gov.ar:11336/632
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Comparison of theoretical white dwarf cooling timescales.Salaris, M.Althaus, Leandro GabrielGarcía-Berro, E.stars: interiorsstars: evolution white dwarfshttps://purl.org/becyt/ford/1https://purl.org/becyt/ford/1.3Context. An accurate assessment of white dwarf cooling times is paramount so that white dwarf cosmochronology of Galactic populations can be put on more solid grounds. This issue is particularly relevant in view of the enhanced observational capabilities provided by the next generation of extremely large telescopes, that will offer more avenues to use white dwarfs as probes of Galactic evolution and test-beds of fundamental physics. <br /> Aims: We estimate for the first time the consistency of results obtained from independent evolutionary codes for white dwarf models with fixed mass and chemical stratification, when the same input physics is employed in the calculations. <br /> Methods: We compute and compare cooling times obtained from two independent and widely used stellar evolution codes, BaSTI and LPCODE evolutionary codes, using exactly the same input physics for 0.55 M<sub>⊙</sub> white dwarf models with both pure carbon and uniform carbon-oxygen (50/50 mass fractions) cores, and pure hydrogen layers with mass fraction q<sub>H</sub> = 10<sup>-4</sup>M<sub>WD</sub> on top of pure helium buffers of mass q<sub>He</sub> = 10<sup>-2</sup>M<sub>WD</sub>. <br /> Results: Using the same radiative and conductive opacities, photospheric boundary conditions, neutrino energy loss rates, and equation of state, cooling times from the two codes agree within ~2% at all luminosities, except when log (L/L<sub>⊙</sub>) > -1.5 where differences up to ~8% do appear, because of the different thermal structures of the first white dwarf converged models at the beginning of the cooling sequence. This agreement is true for both pure carbon and uniform carbon-oxygen stratification core models, and also when the release of latent heat and carbon-oxygen phase separation are considered. We have also determined quantitatively and explained the effect of varying equation of state, low-temperature radiative opacities, and electron conduction opacities in our calculations, <br /> Conclusions: We have assessed for the first time the maximum possible accuracy in the current estimates of white dwarf cooling times, resulting only from the different implementations of the stellar evolution equations and homogeneous input physics in two independent stellar evolution codes. This accuracy amounts to ~2% at luminosities lower than log (L/L<sub>⊙</sub>) ~ -1.5. This difference is smaller than the uncertainties in cooling times attributable to the present uncertainties in the white dwarf chemical stratification. Finally, we extend the scope of our work by providing tabulations of our cooling sequences and the required input physics that can be used as a comparison test of cooling times obtained from other white dwarf evolutionary codes.Fil: Salaris, M.. Astrophysics Research Institute. Liverpool John Moores University. Liverpool Science Park; Reino Unido;Fil: Althaus, Leandro Gabriel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Grupo de Evolución Estelar y Pulsaciones; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Astrofisica la Plata; Argentina;Fil: García-Berro, E.. Departament de Física Aplicada. Universitat Politècnica de Catalunya; Argentina; Institute for Space Studies of Catalonia; Argentina;Edp Sciences S A2013-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/632Salaris, M.; Althaus, Leandro Gabriel; García-Berro, E.; Comparison of theoretical white dwarf cooling timescales.; Edp Sciences S A; Astronomy And Astrophysics; 555; 7-2013; 96-106;0004-6361enginfo:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201220622info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:21:18Zoai:ri.conicet.gov.ar:11336/632instacron: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 10:21:18.405CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Comparison of theoretical white dwarf cooling timescales.
title Comparison of theoretical white dwarf cooling timescales.
spellingShingle Comparison of theoretical white dwarf cooling timescales.
Salaris, M.
stars: interiors
stars: evolution white dwarfs
title_short Comparison of theoretical white dwarf cooling timescales.
title_full Comparison of theoretical white dwarf cooling timescales.
title_fullStr Comparison of theoretical white dwarf cooling timescales.
title_full_unstemmed Comparison of theoretical white dwarf cooling timescales.
title_sort Comparison of theoretical white dwarf cooling timescales.
dc.creator.none.fl_str_mv Salaris, M.
Althaus, Leandro Gabriel
García-Berro, E.
author Salaris, M.
author_facet Salaris, M.
Althaus, Leandro Gabriel
García-Berro, E.
author_role author
author2 Althaus, Leandro Gabriel
García-Berro, E.
author2_role author
author
dc.subject.none.fl_str_mv stars: interiors
stars: evolution white dwarfs
topic stars: interiors
stars: evolution white dwarfs
purl_subject.fl_str_mv https://purl.org/becyt/ford/1
https://purl.org/becyt/ford/1.3
dc.description.none.fl_txt_mv Context. An accurate assessment of white dwarf cooling times is paramount so that white dwarf cosmochronology of Galactic populations can be put on more solid grounds. This issue is particularly relevant in view of the enhanced observational capabilities provided by the next generation of extremely large telescopes, that will offer more avenues to use white dwarfs as probes of Galactic evolution and test-beds of fundamental physics. <br /> Aims: We estimate for the first time the consistency of results obtained from independent evolutionary codes for white dwarf models with fixed mass and chemical stratification, when the same input physics is employed in the calculations. <br /> Methods: We compute and compare cooling times obtained from two independent and widely used stellar evolution codes, BaSTI and LPCODE evolutionary codes, using exactly the same input physics for 0.55 M<sub>⊙</sub> white dwarf models with both pure carbon and uniform carbon-oxygen (50/50 mass fractions) cores, and pure hydrogen layers with mass fraction q<sub>H</sub> = 10<sup>-4</sup>M<sub>WD</sub> on top of pure helium buffers of mass q<sub>He</sub> = 10<sup>-2</sup>M<sub>WD</sub>. <br /> Results: Using the same radiative and conductive opacities, photospheric boundary conditions, neutrino energy loss rates, and equation of state, cooling times from the two codes agree within ~2% at all luminosities, except when log (L/L<sub>⊙</sub>) > -1.5 where differences up to ~8% do appear, because of the different thermal structures of the first white dwarf converged models at the beginning of the cooling sequence. This agreement is true for both pure carbon and uniform carbon-oxygen stratification core models, and also when the release of latent heat and carbon-oxygen phase separation are considered. We have also determined quantitatively and explained the effect of varying equation of state, low-temperature radiative opacities, and electron conduction opacities in our calculations, <br /> Conclusions: We have assessed for the first time the maximum possible accuracy in the current estimates of white dwarf cooling times, resulting only from the different implementations of the stellar evolution equations and homogeneous input physics in two independent stellar evolution codes. This accuracy amounts to ~2% at luminosities lower than log (L/L<sub>⊙</sub>) ~ -1.5. This difference is smaller than the uncertainties in cooling times attributable to the present uncertainties in the white dwarf chemical stratification. Finally, we extend the scope of our work by providing tabulations of our cooling sequences and the required input physics that can be used as a comparison test of cooling times obtained from other white dwarf evolutionary codes.
Fil: Salaris, M.. Astrophysics Research Institute. Liverpool John Moores University. Liverpool Science Park; Reino Unido;
Fil: Althaus, Leandro Gabriel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Grupo de Evolución Estelar y Pulsaciones; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Astrofisica la Plata; Argentina;
Fil: García-Berro, E.. Departament de Física Aplicada. Universitat Politècnica de Catalunya; Argentina; Institute for Space Studies of Catalonia; Argentina;
description Context. An accurate assessment of white dwarf cooling times is paramount so that white dwarf cosmochronology of Galactic populations can be put on more solid grounds. This issue is particularly relevant in view of the enhanced observational capabilities provided by the next generation of extremely large telescopes, that will offer more avenues to use white dwarfs as probes of Galactic evolution and test-beds of fundamental physics. <br /> Aims: We estimate for the first time the consistency of results obtained from independent evolutionary codes for white dwarf models with fixed mass and chemical stratification, when the same input physics is employed in the calculations. <br /> Methods: We compute and compare cooling times obtained from two independent and widely used stellar evolution codes, BaSTI and LPCODE evolutionary codes, using exactly the same input physics for 0.55 M<sub>⊙</sub> white dwarf models with both pure carbon and uniform carbon-oxygen (50/50 mass fractions) cores, and pure hydrogen layers with mass fraction q<sub>H</sub> = 10<sup>-4</sup>M<sub>WD</sub> on top of pure helium buffers of mass q<sub>He</sub> = 10<sup>-2</sup>M<sub>WD</sub>. <br /> Results: Using the same radiative and conductive opacities, photospheric boundary conditions, neutrino energy loss rates, and equation of state, cooling times from the two codes agree within ~2% at all luminosities, except when log (L/L<sub>⊙</sub>) > -1.5 where differences up to ~8% do appear, because of the different thermal structures of the first white dwarf converged models at the beginning of the cooling sequence. This agreement is true for both pure carbon and uniform carbon-oxygen stratification core models, and also when the release of latent heat and carbon-oxygen phase separation are considered. We have also determined quantitatively and explained the effect of varying equation of state, low-temperature radiative opacities, and electron conduction opacities in our calculations, <br /> Conclusions: We have assessed for the first time the maximum possible accuracy in the current estimates of white dwarf cooling times, resulting only from the different implementations of the stellar evolution equations and homogeneous input physics in two independent stellar evolution codes. This accuracy amounts to ~2% at luminosities lower than log (L/L<sub>⊙</sub>) ~ -1.5. This difference is smaller than the uncertainties in cooling times attributable to the present uncertainties in the white dwarf chemical stratification. Finally, we extend the scope of our work by providing tabulations of our cooling sequences and the required input physics that can be used as a comparison test of cooling times obtained from other white dwarf evolutionary codes.
publishDate 2013
dc.date.none.fl_str_mv 2013-07
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/11336/632
Salaris, M.; Althaus, Leandro Gabriel; García-Berro, E.; Comparison of theoretical white dwarf cooling timescales.; Edp Sciences S A; Astronomy And Astrophysics; 555; 7-2013; 96-106;
0004-6361
url http://hdl.handle.net/11336/632
identifier_str_mv Salaris, M.; Althaus, Leandro Gabriel; García-Berro, E.; Comparison of theoretical white dwarf cooling timescales.; Edp Sciences S A; Astronomy And Astrophysics; 555; 7-2013; 96-106;
0004-6361
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201220622
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 S A
publisher.none.fl_str_mv Edp Sciences S A
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
_version_ 1844614200877383680
score 13.070432