X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae

Diagnostics of electron temperature (Te), electron density (ne), and hydrogen column density (NH) from the Chandra High Energy Transmission Grating spectrum of He-like Ne ix in TW Hydrae (TW Hya), in conjunction with a classical accretion model, allow us to infer the accretion rate onto the star dir...

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Authors: Brickhouse, N. S., Cranmer, S. R., Dupree, A. K., Günther, H. M., Luna, Gerardo Juan Manuel, Wolk, S. J.
Format: article
Status:Published version
Publication Date:2012
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/19528
Online Access:http://hdl.handle.net/11336/19528
Access Level:Open access
Keyword:accretion, accretion disks
stars: formation
stars: individual (TW Hydrae)
techniques: spectroscopic
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
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spelling X-Ray Determination of the Variable Rate of Mass Accretion onto TW HydraeBrickhouse, N. S.Cranmer, S. R.Dupree, A. K.Günther, H. M.Luna, Gerardo Juan ManuelWolk, S. J.accretion, accretion disksstars: formationstars: individual (TW Hydrae)techniques: spectroscopichttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Diagnostics of electron temperature (Te), electron density (ne), and hydrogen column density (NH) from the Chandra High Energy Transmission Grating spectrum of He-like Ne ix in TW Hydrae (TW Hya), in conjunction with a classical accretion model, allow us to infer the accretion rate onto the star directly from measurements of the accreting material. The new method introduces the use of the absorption of Ne ix lines as a measure of the column density of the intervening, accreting material. On average, the derived mass accretion rate for TW Hya is 1.5 × 10−9 M yr−1, for a stellar magnetic field strength of 600 G and a filling factor of 3.5%. Three individual Chandra exposures show statistically significant differences in the Ne ix line ratios, indicating changes in NH, Te, and ne by factors of 0.28, 1.6, and 1.3, respectively. In exposures separated by 2.7 days, the observations reported here suggest a five-fold reduction in the accretion rate. This powerful new technique promises to substantially improve our understanding of the accretion process in young stars.Fil: Brickhouse, N. S.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Cranmer, S. R.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Dupree, A. K.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Günther, H. M.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Luna, Gerardo Juan Manuel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Wolk, S. J.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosIOP Publishing2012-11-05info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/19528Brickhouse, N. S.; Cranmer, S. R.; Dupree, A. K.; Günther, H. M.; Luna, Gerardo Juan Manuel; et al.; X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae; IOP Publishing; The Astrophysical Journal Letters; 760; 2; 5-11-2012; L21,1-52041-8205CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/http://iopscience.iop.org/article/10.1088/2041-8205/760/2/L21/metainfo:eu-repo/semantics/altIdentifier/doi/10.1088/2041-8205/760/2/L21info:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1211.1710info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2024-05-08T13:37:46Zoai:ri.conicet.gov.ar:11336/19528instacron: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:34982024-05-08 13:37:46.389CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae
title X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae
spellingShingle X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae
Brickhouse, N. S.
accretion, accretion disks
stars: formation
stars: individual (TW Hydrae)
techniques: spectroscopic
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
title_short X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae
title_full X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae
title_fullStr X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae
title_full_unstemmed X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae
title_sort X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae
dc.creator.none.fl_str_mv Brickhouse, N. S.
Cranmer, S. R.
Dupree, A. K.
Günther, H. M.
Luna, Gerardo Juan Manuel
Wolk, S. J.
author Brickhouse, N. S.
author_facet Brickhouse, N. S.
Cranmer, S. R.
Dupree, A. K.
Günther, H. M.
Luna, Gerardo Juan Manuel
Wolk, S. J.
author_role author
author2 Cranmer, S. R.
Dupree, A. K.
Günther, H. M.
Luna, Gerardo Juan Manuel
Wolk, S. J.
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv accretion, accretion disks
stars: formation
stars: individual (TW Hydrae)
techniques: spectroscopic
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
topic accretion, accretion disks
stars: formation
stars: individual (TW Hydrae)
techniques: spectroscopic
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
description Diagnostics of electron temperature (Te), electron density (ne), and hydrogen column density (NH) from the Chandra High Energy Transmission Grating spectrum of He-like Ne ix in TW Hydrae (TW Hya), in conjunction with a classical accretion model, allow us to infer the accretion rate onto the star directly from measurements of the accreting material. The new method introduces the use of the absorption of Ne ix lines as a measure of the column density of the intervening, accreting material. On average, the derived mass accretion rate for TW Hya is 1.5 × 10−9 M yr−1, for a stellar magnetic field strength of 600 G and a filling factor of 3.5%. Three individual Chandra exposures show statistically significant differences in the Ne ix line ratios, indicating changes in NH, Te, and ne by factors of 0.28, 1.6, and 1.3, respectively. In exposures separated by 2.7 days, the observations reported here suggest a five-fold reduction in the accretion rate. This powerful new technique promises to substantially improve our understanding of the accretion process in young stars.
publishDate 2012
dc.date.none.fl_str_mv 2012-11-05
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/11336/19528
Brickhouse, N. S.; Cranmer, S. R.; Dupree, A. K.; Günther, H. M.; Luna, Gerardo Juan Manuel; et al.; X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae; IOP Publishing; The Astrophysical Journal Letters; 760; 2; 5-11-2012; L21,1-5
2041-8205
CONICET Digital
CONICET
url http://hdl.handle.net/11336/19528
identifier_str_mv Brickhouse, N. S.; Cranmer, S. R.; Dupree, A. K.; Günther, H. M.; Luna, Gerardo Juan Manuel; et al.; X-Ray Determination of the Variable Rate of Mass Accretion onto TW Hydrae; IOP Publishing; The Astrophysical Journal Letters; 760; 2; 5-11-2012; L21,1-5
2041-8205
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://iopscience.iop.org/article/10.1088/2041-8205/760/2/L21/meta
info:eu-repo/semantics/altIdentifier/doi/10.1088/2041-8205/760/2/L21
info:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1211.1710
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
dc.publisher.none.fl_str_mv IOP Publishing
publisher.none.fl_str_mv IOP Publishing
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
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_ 1799194848185548800
score 15,812429

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