Molecular gas associated with RCW 121 and RCW 122
- Autores
- Arnal, Edmundo Marcelo; Duronea, Nicolás Urbano; Testori, Juan Carlos
- Año de publicación
- 2008
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- Aims. We analyse the distribution of the molecular gas towards the region containing the open cluster Havlen-Moffat 1 (HM 1) the Wolf-Rayet stars WR 87, WR 89, and WR 91, and the star forming regions RCW 121 and RCW 122, with the aim of looking for a possible physical relationship among these objects. Methods. We used the carbon monoxide observations carried out at λ ∼ 2.6 mm with the 4 m NANTEN radiotelescope; new flux density determinations derived from already existing radio continuum surveys at 2.417, 5, 8.35, and 14.35 GHz; continuum flux density determinations available in the literature; and the Midcourse Space Experiment (MSX) and the Improved Reprocessing of the IRAS Survey (IRIS) databases. Results. Adopting a distance of 5 kpc for RCW 121 and RCW 122, we found a giant molecular cloud (GMC) with a linear extent of ∼100 × 20 pc to be associated with galactic star-forming regions. The total mass of this GMC is of the order of 1.2 × 10⁶ solar masses and its mean radial velocity is about –15 km s⁻¹. Within the GMC there are individual molecular gas concentrations, having total molecular masses in the range from 4.6 × 10⁴ M⊙ (RCW 122 C) to 2.2 × 10⁵ M⊙ (RCW 122). The CO profiles observed toward the peak of the molecular concentrations are broad, with typical full-width half-maximum around 6 to 7 km s⁻¹, and show line asymmetries and/or double-peaked shape that change with the observed position within a given CO concentration. An analysis of the MSX and IRAS databases show that each CO concentration has a strong IR counterpart. The dust temperature of these concentrations range from 46 K (RCW 121) to 76 K (RCW 122 C). Their infrared luminosity are a few times 10⁵ L⊙. The new radio continuum flux density determinations are in good agreement with previous determinations at other frequencies, and confirm the thermal nature of RCW 121 and RCW 122. Based on the newly-determined 5 GHz flux density, we found that to power these Hii regions, each of them must harbour a sizable number of O type stars. Under the assumption that all the ionizing stars have a O7 V spectral type, at least ∼8 and ∼4 of these stars would be needed to ionize RCW 122 and RCW 121, respectively.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto Argentino de Radioastronomía - Materia
-
Astronomía
ISM: molecules
radio continuum: ISM
infrared: ISM
ISM: HII regions
ISM: individual object: RCW 121
ISM: individual object: RCW 122 - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/123875
Ver los metadatos del registro completo
id |
SEDICI_3da2a7ca936c5d6ed1dc14097eff24e5 |
---|---|
oai_identifier_str |
oai:sedici.unlp.edu.ar:10915/123875 |
network_acronym_str |
SEDICI |
repository_id_str |
1329 |
network_name_str |
SEDICI (UNLP) |
spelling |
Molecular gas associated with RCW 121 and RCW 122Arnal, Edmundo MarceloDuronea, Nicolás UrbanoTestori, Juan CarlosAstronomíaISM: moleculesradio continuum: ISMinfrared: ISMISM: HII regionsISM: individual object: RCW 121ISM: individual object: RCW 122Aims. We analyse the distribution of the molecular gas towards the region containing the open cluster Havlen-Moffat 1 (HM 1) the Wolf-Rayet stars WR 87, WR 89, and WR 91, and the star forming regions RCW 121 and RCW 122, with the aim of looking for a possible physical relationship among these objects. Methods. We used the carbon monoxide observations carried out at λ ∼ 2.6 mm with the 4 m NANTEN radiotelescope; new flux density determinations derived from already existing radio continuum surveys at 2.417, 5, 8.35, and 14.35 GHz; continuum flux density determinations available in the literature; and the <i>Midcourse Space Experiment</i> (MSX) and the <i>Improved Reprocessing of the</i> IRAS <i>Survey</i> (IRIS) databases. Results. Adopting a distance of 5 kpc for RCW 121 and RCW 122, we found a giant molecular cloud (GMC) with a linear extent of ∼100 × 20 pc to be associated with galactic star-forming regions. The total mass of this GMC is of the order of 1.2 × 10⁶ solar masses and its mean radial velocity is about –15 km s⁻¹. Within the GMC there are individual molecular gas concentrations, having total molecular masses in the range from 4.6 × 10⁴ M⊙ (RCW 122 C) to 2.2 × 10⁵ M⊙ (RCW 122). The CO profiles observed toward the peak of the molecular concentrations are broad, with typical full-width half-maximum around 6 to 7 km s⁻¹, and show line asymmetries and/or double-peaked shape that change with the observed position within a given CO concentration. An analysis of the MSX and IRAS databases show that each CO concentration has a strong IR counterpart. The dust temperature of these concentrations range from 46 K (RCW 121) to 76 K (RCW 122 C). Their infrared luminosity are a few times 10⁵ L⊙. The new radio continuum flux density determinations are in good agreement with previous determinations at other frequencies, and confirm the thermal nature of RCW 121 and RCW 122. Based on the newly-determined 5 GHz flux density, we found that to power these Hii regions, each of them must harbour a sizable number of O type stars. Under the assumption that all the ionizing stars have a O7 V spectral type, at least ∼8 and ∼4 of these stars would be needed to ionize RCW 122 and RCW 121, respectively.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomía2008-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf807-818http://sedici.unlp.edu.ar/handle/10915/123875enginfo:eu-repo/semantics/altIdentifier/issn/0004-6361info:eu-repo/semantics/altIdentifier/issn/1432-0746info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:20079126info: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:UNLP2025-09-29T11:29:24Zoai:sedici.unlp.edu.ar:10915/123875Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:29:24.812SEDICI (UNLP) - Universidad Nacional de La Platafalse |
dc.title.none.fl_str_mv |
Molecular gas associated with RCW 121 and RCW 122 |
title |
Molecular gas associated with RCW 121 and RCW 122 |
spellingShingle |
Molecular gas associated with RCW 121 and RCW 122 Arnal, Edmundo Marcelo Astronomía ISM: molecules radio continuum: ISM infrared: ISM ISM: HII regions ISM: individual object: RCW 121 ISM: individual object: RCW 122 |
title_short |
Molecular gas associated with RCW 121 and RCW 122 |
title_full |
Molecular gas associated with RCW 121 and RCW 122 |
title_fullStr |
Molecular gas associated with RCW 121 and RCW 122 |
title_full_unstemmed |
Molecular gas associated with RCW 121 and RCW 122 |
title_sort |
Molecular gas associated with RCW 121 and RCW 122 |
dc.creator.none.fl_str_mv |
Arnal, Edmundo Marcelo Duronea, Nicolás Urbano Testori, Juan Carlos |
author |
Arnal, Edmundo Marcelo |
author_facet |
Arnal, Edmundo Marcelo Duronea, Nicolás Urbano Testori, Juan Carlos |
author_role |
author |
author2 |
Duronea, Nicolás Urbano Testori, Juan Carlos |
author2_role |
author author |
dc.subject.none.fl_str_mv |
Astronomía ISM: molecules radio continuum: ISM infrared: ISM ISM: HII regions ISM: individual object: RCW 121 ISM: individual object: RCW 122 |
topic |
Astronomía ISM: molecules radio continuum: ISM infrared: ISM ISM: HII regions ISM: individual object: RCW 121 ISM: individual object: RCW 122 |
dc.description.none.fl_txt_mv |
Aims. We analyse the distribution of the molecular gas towards the region containing the open cluster Havlen-Moffat 1 (HM 1) the Wolf-Rayet stars WR 87, WR 89, and WR 91, and the star forming regions RCW 121 and RCW 122, with the aim of looking for a possible physical relationship among these objects. Methods. We used the carbon monoxide observations carried out at λ ∼ 2.6 mm with the 4 m NANTEN radiotelescope; new flux density determinations derived from already existing radio continuum surveys at 2.417, 5, 8.35, and 14.35 GHz; continuum flux density determinations available in the literature; and the <i>Midcourse Space Experiment</i> (MSX) and the <i>Improved Reprocessing of the</i> IRAS <i>Survey</i> (IRIS) databases. Results. Adopting a distance of 5 kpc for RCW 121 and RCW 122, we found a giant molecular cloud (GMC) with a linear extent of ∼100 × 20 pc to be associated with galactic star-forming regions. The total mass of this GMC is of the order of 1.2 × 10⁶ solar masses and its mean radial velocity is about –15 km s⁻¹. Within the GMC there are individual molecular gas concentrations, having total molecular masses in the range from 4.6 × 10⁴ M⊙ (RCW 122 C) to 2.2 × 10⁵ M⊙ (RCW 122). The CO profiles observed toward the peak of the molecular concentrations are broad, with typical full-width half-maximum around 6 to 7 km s⁻¹, and show line asymmetries and/or double-peaked shape that change with the observed position within a given CO concentration. An analysis of the MSX and IRAS databases show that each CO concentration has a strong IR counterpart. The dust temperature of these concentrations range from 46 K (RCW 121) to 76 K (RCW 122 C). Their infrared luminosity are a few times 10⁵ L⊙. The new radio continuum flux density determinations are in good agreement with previous determinations at other frequencies, and confirm the thermal nature of RCW 121 and RCW 122. Based on the newly-determined 5 GHz flux density, we found that to power these Hii regions, each of them must harbour a sizable number of O type stars. Under the assumption that all the ionizing stars have a O7 V spectral type, at least ∼8 and ∼4 of these stars would be needed to ionize RCW 122 and RCW 121, respectively. Facultad de Ciencias Astronómicas y Geofísicas Instituto Argentino de Radioastronomía |
description |
Aims. We analyse the distribution of the molecular gas towards the region containing the open cluster Havlen-Moffat 1 (HM 1) the Wolf-Rayet stars WR 87, WR 89, and WR 91, and the star forming regions RCW 121 and RCW 122, with the aim of looking for a possible physical relationship among these objects. Methods. We used the carbon monoxide observations carried out at λ ∼ 2.6 mm with the 4 m NANTEN radiotelescope; new flux density determinations derived from already existing radio continuum surveys at 2.417, 5, 8.35, and 14.35 GHz; continuum flux density determinations available in the literature; and the <i>Midcourse Space Experiment</i> (MSX) and the <i>Improved Reprocessing of the</i> IRAS <i>Survey</i> (IRIS) databases. Results. Adopting a distance of 5 kpc for RCW 121 and RCW 122, we found a giant molecular cloud (GMC) with a linear extent of ∼100 × 20 pc to be associated with galactic star-forming regions. The total mass of this GMC is of the order of 1.2 × 10⁶ solar masses and its mean radial velocity is about –15 km s⁻¹. Within the GMC there are individual molecular gas concentrations, having total molecular masses in the range from 4.6 × 10⁴ M⊙ (RCW 122 C) to 2.2 × 10⁵ M⊙ (RCW 122). The CO profiles observed toward the peak of the molecular concentrations are broad, with typical full-width half-maximum around 6 to 7 km s⁻¹, and show line asymmetries and/or double-peaked shape that change with the observed position within a given CO concentration. An analysis of the MSX and IRAS databases show that each CO concentration has a strong IR counterpart. The dust temperature of these concentrations range from 46 K (RCW 121) to 76 K (RCW 122 C). Their infrared luminosity are a few times 10⁵ L⊙. The new radio continuum flux density determinations are in good agreement with previous determinations at other frequencies, and confirm the thermal nature of RCW 121 and RCW 122. Based on the newly-determined 5 GHz flux density, we found that to power these Hii regions, each of them must harbour a sizable number of O type stars. Under the assumption that all the ionizing stars have a O7 V spectral type, at least ∼8 and ∼4 of these stars would be needed to ionize RCW 122 and RCW 121, respectively. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008-08 |
dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Articulo 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://sedici.unlp.edu.ar/handle/10915/123875 |
url |
http://sedici.unlp.edu.ar/handle/10915/123875 |
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/issn/1432-0746 info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361:20079126 |
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 807-818 |
dc.source.none.fl_str_mv |
reponame:SEDICI (UNLP) instname:Universidad Nacional de La Plata instacron:UNLP |
reponame_str |
SEDICI (UNLP) |
collection |
SEDICI (UNLP) |
instname_str |
Universidad Nacional de La Plata |
instacron_str |
UNLP |
institution |
UNLP |
repository.name.fl_str_mv |
SEDICI (UNLP) - Universidad Nacional de La Plata |
repository.mail.fl_str_mv |
alira@sedici.unlp.edu.ar |
_version_ |
1844616173270859776 |
score |
13.070432 |