Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars

The He II (1640 angstrom) line and the resonance doublet of N V (UV1) provide a good diagnostic tool to constrain the excitation mechanism of hot (T-e > 40,000 K) atmospheric/magnetospheric plasmas in T Tauri stars (TTSs). Making use of the data available in the Hubble Space Telescope archive, th...

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Detalles Bibliográficos
Autor: Gómez De Castro, Ana Inés
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/33398
Acceso en línea:https://hdl.handle.net/20.500.14352/33398
Access Level:acceso abierto
Palabra clave:52
Magnetic fields
Stars: pre-main sequence
Astronomía (Matemáticas)
21 Astronomía y Astrofísica
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oai_identifier_str oai:docta.ucm.es:20.500.14352/33398
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spelling Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri starsGómez De Castro, Ana Inés52Magnetic fieldsStars: pre-main sequenceAstronomía (Matemáticas)21 Astronomía y AstrofísicaThe He II (1640 angstrom) line and the resonance doublet of N V (UV1) provide a good diagnostic tool to constrain the excitation mechanism of hot (T-e > 40,000 K) atmospheric/magnetospheric plasmas in T Tauri stars (TTSs). Making use of the data available in the Hubble Space Telescope archive, this work shows that there are at least two distinct physical components contributing to the radiation in these tracers: the accretion flow sliding on the magnetosphere and the atmosphere. The N V profiles in most sources are symmetric and at rest with respect to the star. The velocity dispersion of the profile increases from non-accreting (sigma = 40 km s (1)) to accreting (sigma = 120 km s (1)) TTSs, suggesting that the macroturbulence field in the line formation region decreases as the stars approach the main sequence. Evidence of the N V line being formed in a hot solar-like wind has been found in RW Aur, HN Tau, and AA Tau. The He II profile has a strong narrow component that dominates the line flux; the dispersion of this component ranges from 20 to 60 km s (1). Current data suggest that both accretion shocks and atmospheric emission might contribute to the line flux. In some sources, the He II line shows a broad and redward-shifted emission component often accompanied by semiforbidden O III] emission that has a critical electron density of similar to 3.4 x 10(10) cm(3). In spite of their different origins (inferred from the kinematics of the line formation region), N V and He II fluxes are strongly correlated, with only the possible exception of some of the heaviest accretors.IOP PublishingUniversidad Complutense de Madrid20132013-10-0120132013-10-01journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/33398reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/333982026-06-02T12:44:21Z
dc.title.none.fl_str_mv Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars
title Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars
spellingShingle Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars
Gómez De Castro, Ana Inés
52
Magnetic fields
Stars: pre-main sequence
Astronomía (Matemáticas)
21 Astronomía y Astrofísica
title_short Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars
title_full Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars
title_fullStr Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars
title_full_unstemmed Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars
title_sort Evidence of hot high velocity photoionized plasma falling on actively accreting T Tauri stars
dc.creator.none.fl_str_mv Gómez De Castro, Ana Inés
author Gómez De Castro, Ana Inés
author_facet Gómez De Castro, Ana Inés
author_role author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 52
Magnetic fields
Stars: pre-main sequence
Astronomía (Matemáticas)
21 Astronomía y Astrofísica
topic 52
Magnetic fields
Stars: pre-main sequence
Astronomía (Matemáticas)
21 Astronomía y Astrofísica
description The He II (1640 angstrom) line and the resonance doublet of N V (UV1) provide a good diagnostic tool to constrain the excitation mechanism of hot (T-e > 40,000 K) atmospheric/magnetospheric plasmas in T Tauri stars (TTSs). Making use of the data available in the Hubble Space Telescope archive, this work shows that there are at least two distinct physical components contributing to the radiation in these tracers: the accretion flow sliding on the magnetosphere and the atmosphere. The N V profiles in most sources are symmetric and at rest with respect to the star. The velocity dispersion of the profile increases from non-accreting (sigma = 40 km s (1)) to accreting (sigma = 120 km s (1)) TTSs, suggesting that the macroturbulence field in the line formation region decreases as the stars approach the main sequence. Evidence of the N V line being formed in a hot solar-like wind has been found in RW Aur, HN Tau, and AA Tau. The He II profile has a strong narrow component that dominates the line flux; the dispersion of this component ranges from 20 to 60 km s (1). Current data suggest that both accretion shocks and atmospheric emission might contribute to the line flux. In some sources, the He II line shows a broad and redward-shifted emission component often accompanied by semiforbidden O III] emission that has a critical electron density of similar to 3.4 x 10(10) cm(3). In spite of their different origins (inferred from the kinematics of the line formation region), N V and He II fluxes are strongly correlated, with only the possible exception of some of the heaviest accretors.
publishDate 2013
dc.date.none.fl_str_mv 2013
2013-10-01
2013
2013-10-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/33398
url https://hdl.handle.net/20.500.14352/33398
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv IOP Publishing
publisher.none.fl_str_mv IOP Publishing
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,228081

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