Reddening and metallicity maps of the Milky Way bulge from VVV and 2MASS â†: III. the first global photometric metallicity map of the Galactic bulge

O. A. Gonzalez, M. Rejkuba, M. Zoccali, E. Valent, D. Minniti, R. Tobar

Resultado de la investigación: Article

60 Citas (Scopus)

Resumen

Aims. We investigate the large-scale metallicity distribution in the Galactic bulge using large spatial coverage to constrain the bulge formation scenario. Methods. We use the VISTA variables in the Via Lactea (VVV) survey data and 2MASS photometry, which cover 320 sqdeg of the Galactic bulge, to derive photometric metallicities by interpolating the (J - Ks)0 colors of individual red giant branch stars based on a set of globular cluster ridge lines. We then use this information to construct the first global metallicity map of the bulge with a resolution of 30′ × 45′. Results. The metallicity map of the bulge revealed a clear vertical metallicity gradient of ∼0.04 dex/deg (∼0.28 dex/kpc), with metal-rich stars ([Fe/H] ∼ 0) dominating the inner bulge in regions closer to the Galactic plane (|b| < 5). At larger scale heights, the mean metallicity of the bulge population becomes significantly more metal poor. Conclusions. This fits in the scenario of a boxy bulge originating from the vertical instability of the Galactic bar, formed early via secular evolution of a two-component stellar disk. Older metal-poor stars dominate at higher scale heights due to the non-mixed orbits of originally hotter thick disk stars.

Idioma originalEnglish
Número de artículoA110
PublicaciónAstronomy and Astrophysics
Volumen552
DOI
EstadoPublished - 17 abr 2013

Huella dactilar

galactic bulge
metallicity
metal
stars
scale height
metals
globular clusters
photometry
ridges
orbits
color
gradients

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Citar esto

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abstract = "Aims. We investigate the large-scale metallicity distribution in the Galactic bulge using large spatial coverage to constrain the bulge formation scenario. Methods. We use the VISTA variables in the Via Lactea (VVV) survey data and 2MASS photometry, which cover 320 sqdeg of the Galactic bulge, to derive photometric metallicities by interpolating the (J - Ks)0 colors of individual red giant branch stars based on a set of globular cluster ridge lines. We then use this information to construct the first global metallicity map of the bulge with a resolution of 30′ × 45′. Results. The metallicity map of the bulge revealed a clear vertical metallicity gradient of ∼0.04 dex/deg (∼0.28 dex/kpc), with metal-rich stars ([Fe/H] ∼ 0) dominating the inner bulge in regions closer to the Galactic plane (|b| < 5). At larger scale heights, the mean metallicity of the bulge population becomes significantly more metal poor. Conclusions. This fits in the scenario of a boxy bulge originating from the vertical instability of the Galactic bar, formed early via secular evolution of a two-component stellar disk. Older metal-poor stars dominate at higher scale heights due to the non-mixed orbits of originally hotter thick disk stars.",
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Reddening and metallicity maps of the Milky Way bulge from VVV and 2MASS ↠: III. the first global photometric metallicity map of the Galactic bulge. / Gonzalez, O. A.; Rejkuba, M.; Zoccali, M.; Valent, E.; Minniti, D.; Tobar, R.

En: Astronomy and Astrophysics, Vol. 552, A110, 17.04.2013.

Resultado de la investigación: Article

TY - JOUR

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T2 - III. the first global photometric metallicity map of the Galactic bulge

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AU - Rejkuba, M.

AU - Zoccali, M.

AU - Valent, E.

AU - Minniti, D.

AU - Tobar, R.

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N2 - Aims. We investigate the large-scale metallicity distribution in the Galactic bulge using large spatial coverage to constrain the bulge formation scenario. Methods. We use the VISTA variables in the Via Lactea (VVV) survey data and 2MASS photometry, which cover 320 sqdeg of the Galactic bulge, to derive photometric metallicities by interpolating the (J - Ks)0 colors of individual red giant branch stars based on a set of globular cluster ridge lines. We then use this information to construct the first global metallicity map of the bulge with a resolution of 30′ × 45′. Results. The metallicity map of the bulge revealed a clear vertical metallicity gradient of ∼0.04 dex/deg (∼0.28 dex/kpc), with metal-rich stars ([Fe/H] ∼ 0) dominating the inner bulge in regions closer to the Galactic plane (|b| < 5). At larger scale heights, the mean metallicity of the bulge population becomes significantly more metal poor. Conclusions. This fits in the scenario of a boxy bulge originating from the vertical instability of the Galactic bar, formed early via secular evolution of a two-component stellar disk. Older metal-poor stars dominate at higher scale heights due to the non-mixed orbits of originally hotter thick disk stars.

AB - Aims. We investigate the large-scale metallicity distribution in the Galactic bulge using large spatial coverage to constrain the bulge formation scenario. Methods. We use the VISTA variables in the Via Lactea (VVV) survey data and 2MASS photometry, which cover 320 sqdeg of the Galactic bulge, to derive photometric metallicities by interpolating the (J - Ks)0 colors of individual red giant branch stars based on a set of globular cluster ridge lines. We then use this information to construct the first global metallicity map of the bulge with a resolution of 30′ × 45′. Results. The metallicity map of the bulge revealed a clear vertical metallicity gradient of ∼0.04 dex/deg (∼0.28 dex/kpc), with metal-rich stars ([Fe/H] ∼ 0) dominating the inner bulge in regions closer to the Galactic plane (|b| < 5). At larger scale heights, the mean metallicity of the bulge population becomes significantly more metal poor. Conclusions. This fits in the scenario of a boxy bulge originating from the vertical instability of the Galactic bar, formed early via secular evolution of a two-component stellar disk. Older metal-poor stars dominate at higher scale heights due to the non-mixed orbits of originally hotter thick disk stars.

KW - Galaxy: abundances

KW - Galaxy: bulge

KW - Galaxy: formation

KW - Stars: abundances

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