The environs of the H II region Gum 31

Autores
Cappa, Cristina Elisabet; Niemelä, Virpi Sinikka; Amorín, R.; Vasquez, Javier
Año de publicación
2008
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Aims. We analyze the distribution of the interstellar matter in the environs of the Hn region Gum 31, excited by the open cluster NGC 3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the surrounding neutral material. Methods. We use neutral hydrogen 21-cm line data, radio continuum images at 0.843, 2.4 and 4.9 GHz, 12CO(1-0) observations, and IRAS and MSX infrared data. Results. Adopting a distance of 3 kpc for the Hn region and the ionizing cluster, we derived an electron density of 33± 3 cm-3 and an ionized mass of (3.3 ±1.1) × 103 M⊙ based on the radio continuum data at 4.9 GHz. The Hl 21-cm line images revealed an Hl shell surrounding the Hn region. The Hl structure is 10.0 ±1.7 pc in radius, has a neutral mass of 1500 ±500 M⊙, and is expanding at 11 km s-1. The associated molecular gas amounts to (1.1 ±0.5) × 105 M⊙, being its volume density of about 350 cm-3. This molecular shell could represent the remains of the cloud where the young open cluster NGC 3324 was born or could have originated by the shock front associated with the Hn region. The difference between the ambient density and the electron density of the Hn region suggests that the Hn region is expanding. The distributions of the ionized and molecular material, along with that of the emission in the MSX band A, suggest that a photodissociation region has developed at the interface between the ionized and molecular gas. The copious UV photon flux from the early type stars in NGC 3324 keeps the Hn region ionized. The characteristics of a relatively large number of the IRAS, MSX, and 2MASS point sources projected onto the molecular envelope are compatible with protostellar candidates, showing the presence of active star forming regions. Very probably, the expansion of the Hn region has triggered stellar formation in the molecular shell.
Instituto Argentino de Radioastronomía
Instituto de Astrofísica de La Plata
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Ciencias Astronómicas
ISM : bubbles
ISM: Hn regions
ISM: individual objects: Gum31
Stars: early-type
Stars: individual: HD 92206
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:10915/84886

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/84886
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling The environs of the H II region Gum 31Cappa, Cristina ElisabetNiemelä, Virpi SinikkaAmorín, R.Vasquez, JavierCiencias AstronómicasISM : bubblesISM: Hn regionsISM: individual objects: Gum31Stars: early-typeStars: individual: HD 92206<b>Aims.</b> We analyze the distribution of the interstellar matter in the environs of the Hn region Gum 31, excited by the open cluster NGC 3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the surrounding neutral material. <b>Methods.</b> We use neutral hydrogen 21-cm line data, radio continuum images at 0.843, 2.4 and 4.9 GHz, 12CO(1-0) observations, and IRAS and MSX infrared data. <b>Results.</b> Adopting a distance of 3 kpc for the Hn region and the ionizing cluster, we derived an electron density of 33± 3 cm-3 and an ionized mass of (3.3 ±1.1) × 103 M⊙ based on the radio continuum data at 4.9 GHz. The Hl 21-cm line images revealed an Hl shell surrounding the Hn region. The Hl structure is 10.0 ±1.7 pc in radius, has a neutral mass of 1500 ±500 M⊙, and is expanding at 11 km s-1. The associated molecular gas amounts to (1.1 ±0.5) × 105 M⊙, being its volume density of about 350 cm-3. This molecular shell could represent the remains of the cloud where the young open cluster NGC 3324 was born or could have originated by the shock front associated with the Hn region. The difference between the ambient density and the electron density of the Hn region suggests that the Hn region is expanding. The distributions of the ionized and molecular material, along with that of the emission in the MSX band A, suggest that a photodissociation region has developed at the interface between the ionized and molecular gas. The copious UV photon flux from the early type stars in NGC 3324 keeps the Hn region ionized. The characteristics of a relatively large number of the IRAS, MSX, and 2MASS point sources projected onto the molecular envelope are compatible with protostellar candidates, showing the presence of active star forming regions. Very probably, the expansion of the Hn region has triggered stellar formation in the molecular shell.Instituto Argentino de RadioastronomíaInstituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísicas2008-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf173-183http://sedici.unlp.edu.ar/handle/10915/84886enginfo:eu-repo/semantics/altIdentifier/issn/0004-6361info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:20067028info: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:UNLP2025-09-29T11:16:14Zoai:sedici.unlp.edu.ar:10915/84886Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:16:15.203SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The environs of the H II region Gum 31
title The environs of the H II region Gum 31
spellingShingle The environs of the H II region Gum 31
Cappa, Cristina Elisabet
Ciencias Astronómicas
ISM : bubbles
ISM: Hn regions
ISM: individual objects: Gum31
Stars: early-type
Stars: individual: HD 92206
title_short The environs of the H II region Gum 31
title_full The environs of the H II region Gum 31
title_fullStr The environs of the H II region Gum 31
title_full_unstemmed The environs of the H II region Gum 31
title_sort The environs of the H II region Gum 31
dc.creator.none.fl_str_mv Cappa, Cristina Elisabet
Niemelä, Virpi Sinikka
Amorín, R.
Vasquez, Javier
author Cappa, Cristina Elisabet
author_facet Cappa, Cristina Elisabet
Niemelä, Virpi Sinikka
Amorín, R.
Vasquez, Javier
author_role author
author2 Niemelä, Virpi Sinikka
Amorín, R.
Vasquez, Javier
author2_role author
author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
ISM : bubbles
ISM: Hn regions
ISM: individual objects: Gum31
Stars: early-type
Stars: individual: HD 92206
topic Ciencias Astronómicas
ISM : bubbles
ISM: Hn regions
ISM: individual objects: Gum31
Stars: early-type
Stars: individual: HD 92206
dc.description.none.fl_txt_mv <b>Aims.</b> We analyze the distribution of the interstellar matter in the environs of the Hn region Gum 31, excited by the open cluster NGC 3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the surrounding neutral material. <b>Methods.</b> We use neutral hydrogen 21-cm line data, radio continuum images at 0.843, 2.4 and 4.9 GHz, 12CO(1-0) observations, and IRAS and MSX infrared data. <b>Results.</b> Adopting a distance of 3 kpc for the Hn region and the ionizing cluster, we derived an electron density of 33± 3 cm-3 and an ionized mass of (3.3 ±1.1) × 103 M⊙ based on the radio continuum data at 4.9 GHz. The Hl 21-cm line images revealed an Hl shell surrounding the Hn region. The Hl structure is 10.0 ±1.7 pc in radius, has a neutral mass of 1500 ±500 M⊙, and is expanding at 11 km s-1. The associated molecular gas amounts to (1.1 ±0.5) × 105 M⊙, being its volume density of about 350 cm-3. This molecular shell could represent the remains of the cloud where the young open cluster NGC 3324 was born or could have originated by the shock front associated with the Hn region. The difference between the ambient density and the electron density of the Hn region suggests that the Hn region is expanding. The distributions of the ionized and molecular material, along with that of the emission in the MSX band A, suggest that a photodissociation region has developed at the interface between the ionized and molecular gas. The copious UV photon flux from the early type stars in NGC 3324 keeps the Hn region ionized. The characteristics of a relatively large number of the IRAS, MSX, and 2MASS point sources projected onto the molecular envelope are compatible with protostellar candidates, showing the presence of active star forming regions. Very probably, the expansion of the Hn region has triggered stellar formation in the molecular shell.
Instituto Argentino de Radioastronomía
Instituto de Astrofísica de La Plata
Facultad de Ciencias Astronómicas y Geofísicas
description <b>Aims.</b> We analyze the distribution of the interstellar matter in the environs of the Hn region Gum 31, excited by the open cluster NGC 3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the surrounding neutral material. <b>Methods.</b> We use neutral hydrogen 21-cm line data, radio continuum images at 0.843, 2.4 and 4.9 GHz, 12CO(1-0) observations, and IRAS and MSX infrared data. <b>Results.</b> Adopting a distance of 3 kpc for the Hn region and the ionizing cluster, we derived an electron density of 33± 3 cm-3 and an ionized mass of (3.3 ±1.1) × 103 M⊙ based on the radio continuum data at 4.9 GHz. The Hl 21-cm line images revealed an Hl shell surrounding the Hn region. The Hl structure is 10.0 ±1.7 pc in radius, has a neutral mass of 1500 ±500 M⊙, and is expanding at 11 km s-1. The associated molecular gas amounts to (1.1 ±0.5) × 105 M⊙, being its volume density of about 350 cm-3. This molecular shell could represent the remains of the cloud where the young open cluster NGC 3324 was born or could have originated by the shock front associated with the Hn region. The difference between the ambient density and the electron density of the Hn region suggests that the Hn region is expanding. The distributions of the ionized and molecular material, along with that of the emission in the MSX band A, suggest that a photodissociation region has developed at the interface between the ionized and molecular gas. The copious UV photon flux from the early type stars in NGC 3324 keeps the Hn region ionized. The characteristics of a relatively large number of the IRAS, MSX, and 2MASS point sources projected onto the molecular envelope are compatible with protostellar candidates, showing the presence of active star forming regions. Very probably, the expansion of the Hn region has triggered stellar formation in the molecular shell.
publishDate 2008
dc.date.none.fl_str_mv 2008-01
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/84886
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dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0004-6361
info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:20067028
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)
dc.format.none.fl_str_mv application/pdf
173-183
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