Globular clusters as tracers of stellar bimodality in elliptical galaxies: The case of NGC 1399

Globular cluster systems (GCSs) frequently show a bimodal distribution of cluster integrated colours. This work explores the arguments to support the idea that the same feature is shared by the diffuse stellar population of the galaxy they are associated with. The particular case of NGC 1399, one of...

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Detalles Bibliográficos
Autores principales: Forte, Juan Carlos, Faifer, Favio Raúl, Geisler, Doug
Formato: Articulo
Lenguaje:Inglés
Publicado: 2005
Materias:
Ciencias Astronómicas
Galaxies: Clusters: Individual: Ngc 1399
Galaxies: Haloes
Galaxies: Starclusters
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83430
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83430
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
Galaxies: Clusters: Individual: Ngc 1399
Galaxies: Haloes
Galaxies: Starclusters
spellingShingle Ciencias Astronómicas
Galaxies: Clusters: Individual: Ngc 1399
Galaxies: Haloes
Galaxies: Starclusters
Forte, Juan Carlos
Faifer, Favio Raúl
Geisler, Doug
Globular clusters as tracers of stellar bimodality in elliptical galaxies: The case of NGC 1399
topic_facet Ciencias Astronómicas
Galaxies: Clusters: Individual: Ngc 1399
Galaxies: Haloes
Galaxies: Starclusters
description Globular cluster systems (GCSs) frequently show a bimodal distribution of cluster integrated colours. This work explores the arguments to support the idea that the same feature is shared by the diffuse stellar population of the galaxy they are associated with. The particular case of NGC 1399, one of the dominant central galaxies in the Fornax cluster, for which a new B surface brightness profile and (B ‒ R<SUB>KC</SUB>) colours are presented, is discussed taking advantage of a recently published wide-field study of its GCS. The results show that the galaxy brightness profile and colour gradient, as well as the behaviour of the cumulative globular cluster specific frequency, are compatible with the presence of two dominant stellar populations, associated with the so-called 'blue' and 'red' globular cluster families. These globular families are characterized by different intrinsic specific frequencies (defined in terms of each stellar population): S<SUB>n</SUB> = 3.3 ± 0.3 in the case of the red globulars and S<SUB>n</SUB> = 14.3 ± 2.5 for the blue ones. We stress that this result does not necessarily conflict with recent works that point out a clear difference between the metallicity distribution of (resolved) halo stars and globulars when comparing their number statistics. The region within 0.5 arcmin of the centre shows a deviation from the model profile (in both surface brightness and colour) that may be explained in terms of the presence of a bulge-like high-metallicity component. Otherwise, the model gives an excellent fit up to 12 arcmin (or 66.5 Kpc) from the centre, the galactocentric limit of our blue brightness profile. The inferred specific frequencies imply that, in terms of their associated stellar populations, the formation of the blue globulars took place with an efficiency about six times higher than that corresponding to their red counterparts. The similarity of the spatial distribution of the blue globulars with that inferred for dark matter, as well as with that of the X-ray-emitting hot gas associated with NGC 1399, is emphasized. The impact of a relatively inconspicuous low-metallicity population, that shares the properties of the blue globulars, as a possible source of chemical enrichment early in the formation history of the galaxy is also briefly discussed.
format Articulo
Articulo
author Forte, Juan Carlos
Faifer, Favio Raúl
Geisler, Doug
author_facet Forte, Juan Carlos
Faifer, Favio Raúl
Geisler, Doug
author_sort Forte, Juan Carlos
title Globular clusters as tracers of stellar bimodality in elliptical galaxies: The case of NGC 1399
title_short Globular clusters as tracers of stellar bimodality in elliptical galaxies: The case of NGC 1399
title_full Globular clusters as tracers of stellar bimodality in elliptical galaxies: The case of NGC 1399
title_fullStr Globular clusters as tracers of stellar bimodality in elliptical galaxies: The case of NGC 1399
title_full_unstemmed Globular clusters as tracers of stellar bimodality in elliptical galaxies: The case of NGC 1399
title_sort globular clusters as tracers of stellar bimodality in elliptical galaxies: the case of ngc 1399
publishDate 2005
url http://sedici.unlp.edu.ar/handle/10915/83430
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AT geislerdoug globularclustersastracersofstellarbimodalityinellipticalgalaxiesthecaseofngc1399
bdutipo_str Repositorios
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