Stellar populations in the Canis Major overdensity

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 si...

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Detalles Bibliográficos
Autores principales: Carraro, Giovanni, Moitinho, André, Vázquez, Rubén Ángel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2008
Materias:
Ciencias Astronómicas
Galaxy: evolution
Galaxy: stellar content
Galaxy: structure
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83524
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83524
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
Galaxy: evolution
Galaxy: stellar content
Galaxy: structure
spellingShingle Ciencias Astronómicas
Galaxy: evolution
Galaxy: stellar content
Galaxy: structure
Carraro, Giovanni
Moitinho, André
Vázquez, Rubén Ángel
Stellar populations in the Canis Major overdensity
topic_facet Ciencias Astronómicas
Galaxy: evolution
Galaxy: stellar content
Galaxy: structure
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.
format Articulo
Articulo
author Carraro, Giovanni
Moitinho, André
Vázquez, Rubén Ángel
author_facet Carraro, Giovanni
Moitinho, André
Vázquez, Rubén Ángel
author_sort Carraro, Giovanni
title Stellar populations in the Canis Major overdensity
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
publishDate 2008
url http://sedici.unlp.edu.ar/handle/10915/83524
work_keys_str_mv AT carrarogiovanni stellarpopulationsinthecanismajoroverdensity
AT moitinhoandre stellarpopulationsinthecanismajoroverdensity
AT vazquezrubenangel stellarpopulationsinthecanismajoroverdensity
bdutipo_str Repositorios
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