VVV survey near-infrared photometry of known bulge RR Lyrae stars: The distance to the galactic center and absence of a barred distribution of the metal-poor population

I. Dékány, D. Minniti, M. Catelan, M. Zoccali, R. K. Saito, M. Hempel, O. A. Gonzalez

Resultado de la investigación: Article

88 Citas (Scopus)

Resumen

We have combined optical and near-infrared data of known RR Lyrae (RRL) stars in the bulge in order to study the spatial distribution of its metal-poor component by measuring precise reddening values and distances of 7663 fundamental-mode RRL stars with high-quality photometry. We obtain a distance to the Galactic center of R 0 = 8.33 ± 0.05 ± 0.14 kpc. We find that the spatial distribution of the RRL stars differs from the structures traced by the predominantly metal-rich red clump (RC) stars. Unlike the RC stars, the RRL stars do not trace a strong bar, but have a more spheroidal, centrally concentrated distribution, showing only a slight elongation in its very center. We find a hint of bimodality in the density distribution at high southern latitudes (b < -5°), which needs to be confirmed by extending the areal coverage of the current census. The different spatial distributions of the metal-rich and metal-poor stellar populations suggest that the Milky Way has a composite bulge.

Idioma originalEnglish
Número de artículoL19
PublicaciónAstrophysical Journal Letters
Volumen776
N.º2
DOI
EstadoPublished - 20 oct 2013

Huella dactilar

infrared photometry
near infrared
stars
metal
spatial distribution
metals
clumps
census
elongation
photometry
density distribution
distribution
composite materials

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Citar esto

@article{722e69cd7241424ea57323ef48be6080,
title = "VVV survey near-infrared photometry of known bulge RR Lyrae stars: The distance to the galactic center and absence of a barred distribution of the metal-poor population",
abstract = "We have combined optical and near-infrared data of known RR Lyrae (RRL) stars in the bulge in order to study the spatial distribution of its metal-poor component by measuring precise reddening values and distances of 7663 fundamental-mode RRL stars with high-quality photometry. We obtain a distance to the Galactic center of R 0 = 8.33 ± 0.05 ± 0.14 kpc. We find that the spatial distribution of the RRL stars differs from the structures traced by the predominantly metal-rich red clump (RC) stars. Unlike the RC stars, the RRL stars do not trace a strong bar, but have a more spheroidal, centrally concentrated distribution, showing only a slight elongation in its very center. We find a hint of bimodality in the density distribution at high southern latitudes (b < -5°), which needs to be confirmed by extending the areal coverage of the current census. The different spatial distributions of the metal-rich and metal-poor stellar populations suggest that the Milky Way has a composite bulge.",
keywords = "Galaxy: bulge, Galaxy: stellar content, Galaxy: structure, stars: variables: RR Lyrae",
author = "I. D{\'e}k{\'a}ny and D. Minniti and M. Catelan and M. Zoccali and Saito, {R. K.} and M. Hempel and Gonzalez, {O. A.}",
year = "2013",
month = "10",
day = "20",
doi = "10.1088/2041-8205/776/2/L19",
language = "English",
volume = "776",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "2",

}

VVV survey near-infrared photometry of known bulge RR Lyrae stars : The distance to the galactic center and absence of a barred distribution of the metal-poor population. / Dékány, I.; Minniti, D.; Catelan, M.; Zoccali, M.; Saito, R. K.; Hempel, M.; Gonzalez, O. A.

En: Astrophysical Journal Letters, Vol. 776, N.º 2, L19, 20.10.2013.

Resultado de la investigación: Article

TY - JOUR

T1 - VVV survey near-infrared photometry of known bulge RR Lyrae stars

T2 - The distance to the galactic center and absence of a barred distribution of the metal-poor population

AU - Dékány, I.

AU - Minniti, D.

AU - Catelan, M.

AU - Zoccali, M.

AU - Saito, R. K.

AU - Hempel, M.

AU - Gonzalez, O. A.

PY - 2013/10/20

Y1 - 2013/10/20

N2 - We have combined optical and near-infrared data of known RR Lyrae (RRL) stars in the bulge in order to study the spatial distribution of its metal-poor component by measuring precise reddening values and distances of 7663 fundamental-mode RRL stars with high-quality photometry. We obtain a distance to the Galactic center of R 0 = 8.33 ± 0.05 ± 0.14 kpc. We find that the spatial distribution of the RRL stars differs from the structures traced by the predominantly metal-rich red clump (RC) stars. Unlike the RC stars, the RRL stars do not trace a strong bar, but have a more spheroidal, centrally concentrated distribution, showing only a slight elongation in its very center. We find a hint of bimodality in the density distribution at high southern latitudes (b < -5°), which needs to be confirmed by extending the areal coverage of the current census. The different spatial distributions of the metal-rich and metal-poor stellar populations suggest that the Milky Way has a composite bulge.

AB - We have combined optical and near-infrared data of known RR Lyrae (RRL) stars in the bulge in order to study the spatial distribution of its metal-poor component by measuring precise reddening values and distances of 7663 fundamental-mode RRL stars with high-quality photometry. We obtain a distance to the Galactic center of R 0 = 8.33 ± 0.05 ± 0.14 kpc. We find that the spatial distribution of the RRL stars differs from the structures traced by the predominantly metal-rich red clump (RC) stars. Unlike the RC stars, the RRL stars do not trace a strong bar, but have a more spheroidal, centrally concentrated distribution, showing only a slight elongation in its very center. We find a hint of bimodality in the density distribution at high southern latitudes (b < -5°), which needs to be confirmed by extending the areal coverage of the current census. The different spatial distributions of the metal-rich and metal-poor stellar populations suggest that the Milky Way has a composite bulge.

KW - Galaxy: bulge

KW - Galaxy: stellar content

KW - Galaxy: structure

KW - stars: variables: RR Lyrae

UR - http://www.scopus.com/inward/record.url?scp=84885356600&partnerID=8YFLogxK

U2 - 10.1088/2041-8205/776/2/L19

DO - 10.1088/2041-8205/776/2/L19

M3 - Article

AN - SCOPUS:84885356600

VL - 776

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 2

M1 - L19

ER -