Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946

Autores
García Benito, Rubén; Díaz Beltrán, Ángeles Isabel; Hägele, Guillermo Federico; Pérez Montero, E.; López, J; Vílchez, J. M.; Pérez, E.; Terlevich, Elena; Terlevich, Roberto; Rosa González, D.
Año de publicación
2010
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Integral field spectroscopy obtained with the Potsdam Multi-Aperture Spectrophotometer Fiber Package (PPak) and the 3.5-m telescope at the Calar Alto Observatory has been used to study an outer H ii region complex in the well-studied galaxy NGC-6946. This technique provides detailed maps of the region in different emission lines, yielding spatially resolved information about the physical properties of the gas. The configuration was chosen to cover the whole spectrum from 3600 up to 10-000-Å, allowing the measurement of the near-infrared [S-iii] lines. We selected four luminous knots to perform a detailed integrated spectroscopic analysis of these structures and of the whole PPak field of view (FOV). For all the knots the electron density has been found to be very similar and below 100 cm-3. The [O-iii] electron temperature was measured in knots A, B, C and in the integrated PPak field, and was found to be around 8000 K. The temperatures of [O-ii] and [S-iii] were estimated in the four cases. The elemental abundances computed from the 'direct method' are typical of high-metallicity disc H-ii regions, with a mean value of 12+log(O/H) = 8.65, comparable to what has been found in this galaxy by other authors for regions at similar galactocentric distance. Therefore a remarkable abundance uniformity is found despite the different excitations found throughout the nebula. However, due to the quality of the data, the electron temperatures and metallicities obtained have associated errors comparable to the typical dispersion found in empirical calibrations.Wolf-Rayet (WR) features have been detected in three of the knots, leading to a derived total number of WR stars of 125, 22 and 5 for knots A, C and B, respectively. The ratios of the numbers of WR to O stars are consistent with the prediction of Starburst99 for individual bursts with an age about 4-Myr. Knot D, with no WR features, shows weak Hα emission, low excitation and the lowest Hβ equivalent width, all of which points to a more evolved state.The integrated spectrum of the whole PPak FOV shows high excitation and a relatively evolved age that does not correspond to the individual knot evolutionary stages. Some effects associated with the loss of spatial resolution are also evidenced by the higher ionizing temperature that is deduced from the η' parameter measured in the integrated PPak spectrum with respect to that of the individual knots.
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Ciencias Astronómicas
H ii regions
ISM: abundances
Techniques: spectroscopic
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/82548

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/82548
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network_name_str SEDICI (UNLP)
spelling Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946García Benito, RubénDíaz Beltrán, Ángeles IsabelHägele, Guillermo FedericoPérez Montero, E.López, JVílchez, J. M.Pérez, E.Terlevich, ElenaTerlevich, RobertoRosa González, D.Ciencias AstronómicasH ii regionsISM: abundancesTechniques: spectroscopicIntegral field spectroscopy obtained with the Potsdam Multi-Aperture Spectrophotometer Fiber Package (PPak) and the 3.5-m telescope at the Calar Alto Observatory has been used to study an outer H ii region complex in the well-studied galaxy NGC-6946. This technique provides detailed maps of the region in different emission lines, yielding spatially resolved information about the physical properties of the gas. The configuration was chosen to cover the whole spectrum from 3600 up to 10-000-Å, allowing the measurement of the near-infrared [S-iii] lines. We selected four luminous knots to perform a detailed integrated spectroscopic analysis of these structures and of the whole PPak field of view (FOV). For all the knots the electron density has been found to be very similar and below 100 cm-3. The [O-iii] electron temperature was measured in knots A, B, C and in the integrated PPak field, and was found to be around 8000 K. The temperatures of [O-ii] and [S-iii] were estimated in the four cases. The elemental abundances computed from the 'direct method' are typical of high-metallicity disc H-ii regions, with a mean value of 12+log(O/H) = 8.65, comparable to what has been found in this galaxy by other authors for regions at similar galactocentric distance. Therefore a remarkable abundance uniformity is found despite the different excitations found throughout the nebula. However, due to the quality of the data, the electron temperatures and metallicities obtained have associated errors comparable to the typical dispersion found in empirical calibrations.Wolf-Rayet (WR) features have been detected in three of the knots, leading to a derived total number of WR stars of 125, 22 and 5 for knots A, C and B, respectively. The ratios of the numbers of WR to O stars are consistent with the prediction of Starburst99 for individual bursts with an age about 4-Myr. Knot D, with no WR features, shows weak Hα emission, low excitation and the lowest Hβ equivalent width, all of which points to a more evolved state.The integrated spectrum of the whole PPak FOV shows high excitation and a relatively evolved age that does not correspond to the individual knot evolutionary stages. Some effects associated with the loss of spatial resolution are also evidenced by the higher ionizing temperature that is deduced from the η' parameter measured in the integrated PPak spectrum with respect to that of the individual knots.Facultad de Ciencias Astronómicas y Geofísicas2010info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf2234-2255http://sedici.unlp.edu.ar/handle/10915/82548enginfo:eu-repo/semantics/altIdentifier/issn/0035-8711info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1365-2966.2010.17269.xinfo:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:15:27Zoai:sedici.unlp.edu.ar:10915/82548Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:27.445SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946
title Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946
spellingShingle Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946
García Benito, Rubén
Ciencias Astronómicas
H ii regions
ISM: abundances
Techniques: spectroscopic
title_short Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946
title_full Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946
title_fullStr Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946
title_full_unstemmed Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946
title_sort Integral field spectroscopy of HII region complexes: The outer disc of NGC-6946
dc.creator.none.fl_str_mv García Benito, Rubén
Díaz Beltrán, Ángeles Isabel
Hägele, Guillermo Federico
Pérez Montero, E.
López, J
Vílchez, J. M.
Pérez, E.
Terlevich, Elena
Terlevich, Roberto
Rosa González, D.
author García Benito, Rubén
author_facet García Benito, Rubén
Díaz Beltrán, Ángeles Isabel
Hägele, Guillermo Federico
Pérez Montero, E.
López, J
Vílchez, J. M.
Pérez, E.
Terlevich, Elena
Terlevich, Roberto
Rosa González, D.
author_role author
author2 Díaz Beltrán, Ángeles Isabel
Hägele, Guillermo Federico
Pérez Montero, E.
López, J
Vílchez, J. M.
Pérez, E.
Terlevich, Elena
Terlevich, Roberto
Rosa González, D.
author2_role author
author
author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
H ii regions
ISM: abundances
Techniques: spectroscopic
topic Ciencias Astronómicas
H ii regions
ISM: abundances
Techniques: spectroscopic
dc.description.none.fl_txt_mv Integral field spectroscopy obtained with the Potsdam Multi-Aperture Spectrophotometer Fiber Package (PPak) and the 3.5-m telescope at the Calar Alto Observatory has been used to study an outer H ii region complex in the well-studied galaxy NGC-6946. This technique provides detailed maps of the region in different emission lines, yielding spatially resolved information about the physical properties of the gas. The configuration was chosen to cover the whole spectrum from 3600 up to 10-000-Å, allowing the measurement of the near-infrared [S-iii] lines. We selected four luminous knots to perform a detailed integrated spectroscopic analysis of these structures and of the whole PPak field of view (FOV). For all the knots the electron density has been found to be very similar and below 100 cm-3. The [O-iii] electron temperature was measured in knots A, B, C and in the integrated PPak field, and was found to be around 8000 K. The temperatures of [O-ii] and [S-iii] were estimated in the four cases. The elemental abundances computed from the 'direct method' are typical of high-metallicity disc H-ii regions, with a mean value of 12+log(O/H) = 8.65, comparable to what has been found in this galaxy by other authors for regions at similar galactocentric distance. Therefore a remarkable abundance uniformity is found despite the different excitations found throughout the nebula. However, due to the quality of the data, the electron temperatures and metallicities obtained have associated errors comparable to the typical dispersion found in empirical calibrations.Wolf-Rayet (WR) features have been detected in three of the knots, leading to a derived total number of WR stars of 125, 22 and 5 for knots A, C and B, respectively. The ratios of the numbers of WR to O stars are consistent with the prediction of Starburst99 for individual bursts with an age about 4-Myr. Knot D, with no WR features, shows weak Hα emission, low excitation and the lowest Hβ equivalent width, all of which points to a more evolved state.The integrated spectrum of the whole PPak FOV shows high excitation and a relatively evolved age that does not correspond to the individual knot evolutionary stages. Some effects associated with the loss of spatial resolution are also evidenced by the higher ionizing temperature that is deduced from the η' parameter measured in the integrated PPak spectrum with respect to that of the individual knots.
Facultad de Ciencias Astronómicas y Geofísicas
description Integral field spectroscopy obtained with the Potsdam Multi-Aperture Spectrophotometer Fiber Package (PPak) and the 3.5-m telescope at the Calar Alto Observatory has been used to study an outer H ii region complex in the well-studied galaxy NGC-6946. This technique provides detailed maps of the region in different emission lines, yielding spatially resolved information about the physical properties of the gas. The configuration was chosen to cover the whole spectrum from 3600 up to 10-000-Å, allowing the measurement of the near-infrared [S-iii] lines. We selected four luminous knots to perform a detailed integrated spectroscopic analysis of these structures and of the whole PPak field of view (FOV). For all the knots the electron density has been found to be very similar and below 100 cm-3. The [O-iii] electron temperature was measured in knots A, B, C and in the integrated PPak field, and was found to be around 8000 K. The temperatures of [O-ii] and [S-iii] were estimated in the four cases. The elemental abundances computed from the 'direct method' are typical of high-metallicity disc H-ii regions, with a mean value of 12+log(O/H) = 8.65, comparable to what has been found in this galaxy by other authors for regions at similar galactocentric distance. Therefore a remarkable abundance uniformity is found despite the different excitations found throughout the nebula. However, due to the quality of the data, the electron temperatures and metallicities obtained have associated errors comparable to the typical dispersion found in empirical calibrations.Wolf-Rayet (WR) features have been detected in three of the knots, leading to a derived total number of WR stars of 125, 22 and 5 for knots A, C and B, respectively. The ratios of the numbers of WR to O stars are consistent with the prediction of Starburst99 for individual bursts with an age about 4-Myr. Knot D, with no WR features, shows weak Hα emission, low excitation and the lowest Hβ equivalent width, all of which points to a more evolved state.The integrated spectrum of the whole PPak FOV shows high excitation and a relatively evolved age that does not correspond to the individual knot evolutionary stages. Some effects associated with the loss of spatial resolution are also evidenced by the higher ionizing temperature that is deduced from the η' parameter measured in the integrated PPak spectrum with respect to that of the individual knots.
publishDate 2010
dc.date.none.fl_str_mv 2010
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info:eu-repo/semantics/publishedVersion
Articulo
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format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/82548
url http://sedici.unlp.edu.ar/handle/10915/82548
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0035-8711
info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1365-2966.2010.17269.x
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
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