The environs of the H II region Gum 31

<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. &l...

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Autores principales: Cappa, Cristina Elisabet, Niemelä, Virpi Sinikka, Amorín, R., Vasquez, Javier
Formato: Articulo
Lenguaje:Inglés
Publicado: 2008
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84886
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id I19-R120-10915-84886
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
ISM : bubbles
ISM: Hn regions
ISM: individual objects: Gum31
Stars: early-type
Stars: individual: HD 92206
spellingShingle Ciencias Astronómicas
ISM : bubbles
ISM: Hn regions
ISM: individual objects: Gum31
Stars: early-type
Stars: individual: HD 92206
Cappa, Cristina Elisabet
Niemelä, Virpi Sinikka
Amorín, R.
Vasquez, Javier
The environs of the H II region Gum 31
topic_facet Ciencias Astronómicas
ISM : bubbles
ISM: Hn regions
ISM: individual objects: Gum31
Stars: early-type
Stars: individual: HD 92206
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.
format Articulo
Articulo
author Cappa, Cristina Elisabet
Niemelä, Virpi Sinikka
Amorín, R.
Vasquez, Javier
author_facet Cappa, Cristina Elisabet
Niemelä, Virpi Sinikka
Amorín, R.
Vasquez, Javier
author_sort Cappa, Cristina Elisabet
title The environs of the H II region Gum 31
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 environs of the h ii region gum 31
publishDate 2008
url http://sedici.unlp.edu.ar/handle/10915/84886
work_keys_str_mv AT cappacristinaelisabet theenvironsofthehiiregiongum31
AT niemelavirpisinikka theenvironsofthehiiregiongum31
AT amorinr theenvironsofthehiiregiongum31
AT vasquezjavier theenvironsofthehiiregiongum31
AT cappacristinaelisabet environsofthehiiregiongum31
AT niemelavirpisinikka environsofthehiiregiongum31
AT amorinr environsofthehiiregiongum31
AT vasquezjavier environsofthehiiregiongum31
bdutipo_str Repositorios
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