Stellar populations in the Canis Major overdensity

Autores
Carraro, Giovanni; Moitinho, André; Vázquez, Rubén Ángel
Año de publicación
2008
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We performed a photometric multicolour survey of the core of the Canis Major overdensity at l ≈ 244°, b ≈ —8°.0, reaching V ~ 22 and covering 0.3 x 1.0 arcmin2. The main aim is to unravel the complex mixture of stellar populations toward this Galactic direction, where in the recent past important signatures of an accretion event have been claimed to be detected. While our previous investigations were based on disjointed pointings aimed at revealing the large-scale structure of the third Galactic Quadrant, we now focus on a complete coverage of a smaller field centred on the Canis Major overdensity. A large wavelength baseline, in the UBVRI bands, allows us to build up a suite of colour-colour and colour-magnitude diagrams, providing a much better diagnostic tool to disentangle the stellar populations of the region. In fact, the simple use of one colour-magnitude diagram, widely employed in all the previous studies defending the existence of the Canis Major galaxy, does not allow one to separate the effects of the different parameters (reddening, age, metallicity and distance) involved in the interpretation of data, forcing to rely on heavy modelling. In agreement with our previous studies, in the same general region ofthe Milky Way, we recognize a young stellar population compatible with the expected structure and extension of the Local (Orion) and Outer (NormaCygnus) spiral arms in the Third Galactic Quadrant. Moreover, we interpret the conspicuous intermediate-age metal-poor population as belonging to the Galactic thick disc, distorted by the effect of strong disc warping at this latitude, and to the Galactic halo.
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Ciencias Astronómicas
Galaxy: evolution
Galaxy: stellar content
Galaxy: structure
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:10915/83524

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network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Stellar populations in the Canis Major overdensityCarraro, GiovanniMoitinho, AndréVázquez, Rubén ÁngelCiencias AstronómicasGalaxy: evolutionGalaxy: stellar contentGalaxy: structureWe performed a photometric multicolour survey of the core of the Canis Major overdensity at l ≈ 244°, b ≈ —8°.0, reaching V ~ 22 and covering 0.3 x 1.0 arcmin2. The main aim is to unravel the complex mixture of stellar populations toward this Galactic direction, where in the recent past important signatures of an accretion event have been claimed to be detected. While our previous investigations were based on disjointed pointings aimed at revealing the large-scale structure of the third Galactic Quadrant, we now focus on a complete coverage of a smaller field centred on the Canis Major overdensity. A large wavelength baseline, in the UBVRI bands, allows us to build up a suite of colour-colour and colour-magnitude diagrams, providing a much better diagnostic tool to disentangle the stellar populations of the region. In fact, the simple use of one colour-magnitude diagram, widely employed in all the previous studies defending the existence of the Canis Major galaxy, does not allow one to separate the effects of the different parameters (reddening, age, metallicity and distance) involved in the interpretation of data, forcing to rely on heavy modelling. In agreement with our previous studies, in the same general region ofthe Milky Way, we recognize a young stellar population compatible with the expected structure and extension of the Local (Orion) and Outer (NormaCygnus) spiral arms in the Third Galactic Quadrant. Moreover, we interpret the conspicuous intermediate-age metal-poor population as belonging to the Galactic thick disc, distorted by the effect of strong disc warping at this latitude, and to the Galactic halo.Facultad de Ciencias Astronómicas y Geofísicas2008info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf1597-1604http://sedici.unlp.edu.ar/handle/10915/83524enginfo:eu-repo/semantics/altIdentifier/issn/0035-8711info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1365-2966.2008.12953.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:UNLP2025-09-29T11:15:41Zoai:sedici.unlp.edu.ar:10915/83524Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:41.98SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Stellar populations in the Canis Major overdensity
title Stellar populations in the Canis Major overdensity
spellingShingle Stellar populations in the Canis Major overdensity
Carraro, Giovanni
Ciencias Astronómicas
Galaxy: evolution
Galaxy: stellar content
Galaxy: structure
title_short Stellar populations in the Canis Major overdensity
title_full Stellar populations in the Canis Major overdensity
title_fullStr Stellar populations in the Canis Major overdensity
title_full_unstemmed Stellar populations in the Canis Major overdensity
title_sort Stellar populations in the Canis Major overdensity
dc.creator.none.fl_str_mv Carraro, Giovanni
Moitinho, André
Vázquez, Rubén Ángel
author Carraro, Giovanni
author_facet Carraro, Giovanni
Moitinho, André
Vázquez, Rubén Ángel
author_role author
author2 Moitinho, André
Vázquez, Rubén Ángel
author2_role author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
Galaxy: evolution
Galaxy: stellar content
Galaxy: structure
topic Ciencias Astronómicas
Galaxy: evolution
Galaxy: stellar content
Galaxy: structure
dc.description.none.fl_txt_mv We performed a photometric multicolour survey of the core of the Canis Major overdensity at l ≈ 244°, b ≈ —8°.0, reaching V ~ 22 and covering 0.3 x 1.0 arcmin2. The main aim is to unravel the complex mixture of stellar populations toward this Galactic direction, where in the recent past important signatures of an accretion event have been claimed to be detected. While our previous investigations were based on disjointed pointings aimed at revealing the large-scale structure of the third Galactic Quadrant, we now focus on a complete coverage of a smaller field centred on the Canis Major overdensity. A large wavelength baseline, in the UBVRI bands, allows us to build up a suite of colour-colour and colour-magnitude diagrams, providing a much better diagnostic tool to disentangle the stellar populations of the region. In fact, the simple use of one colour-magnitude diagram, widely employed in all the previous studies defending the existence of the Canis Major galaxy, does not allow one to separate the effects of the different parameters (reddening, age, metallicity and distance) involved in the interpretation of data, forcing to rely on heavy modelling. In agreement with our previous studies, in the same general region ofthe Milky Way, we recognize a young stellar population compatible with the expected structure and extension of the Local (Orion) and Outer (NormaCygnus) spiral arms in the Third Galactic Quadrant. Moreover, we interpret the conspicuous intermediate-age metal-poor population as belonging to the Galactic thick disc, distorted by the effect of strong disc warping at this latitude, and to the Galactic halo.
Facultad de Ciencias Astronómicas y Geofísicas
description We performed a photometric multicolour survey of the core of the Canis Major overdensity at l ≈ 244°, b ≈ —8°.0, reaching V ~ 22 and covering 0.3 x 1.0 arcmin2. The main aim is to unravel the complex mixture of stellar populations toward this Galactic direction, where in the recent past important signatures of an accretion event have been claimed to be detected. While our previous investigations were based on disjointed pointings aimed at revealing the large-scale structure of the third Galactic Quadrant, we now focus on a complete coverage of a smaller field centred on the Canis Major overdensity. A large wavelength baseline, in the UBVRI bands, allows us to build up a suite of colour-colour and colour-magnitude diagrams, providing a much better diagnostic tool to disentangle the stellar populations of the region. In fact, the simple use of one colour-magnitude diagram, widely employed in all the previous studies defending the existence of the Canis Major galaxy, does not allow one to separate the effects of the different parameters (reddening, age, metallicity and distance) involved in the interpretation of data, forcing to rely on heavy modelling. In agreement with our previous studies, in the same general region ofthe Milky Way, we recognize a young stellar population compatible with the expected structure and extension of the Local (Orion) and Outer (NormaCygnus) spiral arms in the Third Galactic Quadrant. Moreover, we interpret the conspicuous intermediate-age metal-poor population as belonging to the Galactic thick disc, distorted by the effect of strong disc warping at this latitude, and to the Galactic halo.
publishDate 2008
dc.date.none.fl_str_mv 2008
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/10915/83524
url http://sedici.unlp.edu.ar/handle/10915/83524
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.1365-2966.2008.12953.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)
dc.format.none.fl_str_mv application/pdf
1597-1604
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
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