J/A+A/599/A12 [Fe/H] and kinematics of 26 Galactic bulge fields (Zoccali+, 2017)
The GIRAFFE Inner Bulge Survey (GIBS).
III. Metallicity distributions and kinematics of 26 Galactic bulge fields.
Zoccali, M., Vasquez, S., Gonzalez, O. A., Valenti, E.,
Rojas-Arriagada, A., Minniti, J., Rejkuba, M., Minniti, D., McWilliam, A.,
Babusiaux, C., Hill, V., Renzini, A.
<Astron. Astrophys. 599, A12 (2017)>
=2017A&A...599A..12Z 2017A&A...599A..12Z (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Abundances ; Photometry ; Radial velocities
Keywords: stars: abundances - Galaxy: bulge - Galaxy: structure -
Galaxy: kinematics and dynamics - Galaxy: stellar content
Abstract:
Several recent studies have demonstrated that the Galactic bulge hosts
two components with different mean metallicities, and possibly
different spatial distribution and kinematics. As a consequence, both
the metallicity distribution and the radial velocity of bulge stars
vary across different line of sights. We present here the metallicity
distribution function of red clump stars in 26 fields spread across a
wide area of the bulge, with special emphasis on fields close to
Galactic plane, at latitudes b=-2 and b=-1, that were not explored
before. This work includes new metallicities from a sample of ∼5000 K
giant stars, observed at spectral resolution R∼6500, in the Calcium II
Triplet region. They are the main dataset of the GIRAFFE Inner Bulge
Survey. As part of the same survey we have previously published
results for a sample of ∼600 K giant stars, at latitude b~-4 derived
from higher resolution spectra (R=22500). The combined sample allows
us to trace and characterize the metal poor and metal rich bulge
populations down to the inner bulge. We present a density map for each
of the two components. Contrary to the expectations from previous
works, we found the metal poor population to be more centrally
concentrated than the metal rich one, and with a more axisymmetric
spatial distribution. The metal rich population, on the other hand, is
arranged in a boxy distribution, consistent with an edge-on bar. By
coupling metallicities and radial velocities we show that the metal
poor population has a velocity dispersion that varies rather mildly
with latitude. On the contrary, the metal rich population has a low
velocity dispersion far from the plane (b=-8.5) but it has a steeper
gradient with latitude, becoming higher than the metal poor one in the
innermost field (b=-1). This work provides new observational
constraints on the actual chemodynamical properties of the Galactic
bulge, that will help discriminating among different formation models.
Description:
In this table we provide coordinates, VVV magnitudes, radial
velocities and metallicities for ∼5000 K giant stars observed at
spectral resolution R∼6500, in the Calcium II Triplet region. Their
metallicities were derived using a CaT calibration developed for this
survey (Vasquez et al., 2015, Cat. J/A+A/555/A91). In addition, a set
of ∼600 K giant stars, corresponding to the high resolution portion
(R=22500) of the survey, and published in the paper II of this series
(Gonzalez et al., 2015, Cat. J/A+A/584/A46), is included for
completitude.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 5588 Coordinates, VVV magnitudes, radial velocities and
metallicities of the program stars
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See also:
J/A+A/562/A66 : GIRAFFE Inner Bulge Survey (GIBS). I. (Zoccali+, 2014)
J/A+A/584/A46 : GIRAFFE Inner Bulge Survey (GIBS). II. (Gonzalez+, 2015)
J/A+A/580/A121 : Galactic bulge stars CaT/[Fe/H] calibration (Vasquez+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- ID Label
25- 34 F10.6 deg RAdeg Right ascension (J2000)
37- 46 F10.6 deg DEdeg Declination (J2000)
49- 54 F6.3 mag Jmag ?=99.999 VVV J magnitude
57- 62 F6.3 mag Ksmag ?=99.999 VVV Ks magnitude
65- 71 F7.2 km/s HRV Heliocentric radial velocity
74- 79 F6.2 km/s e_HRV Heliocentric radial velocity error
82- 86 F5.2 [Sun] [Fe/H] Metallicity
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Acknowledgements:
Manuela Zoccali, mzoccali(at)astro.puc.cl
References:
Zoccali et al., Paper I 2014A&A...562A..66Z 2014A&A...562A..66Z, Cat. J/A+A/562/A66
Gonzalez et al., Paper II 2015A&A...584A..46G 2015A&A...584A..46G, Cat. J/A+A/584/A46
Vasquez et al., CaT calibration 2015A&A...580A.121V 2015A&A...580A.121V, Cat. J/A+A/580/A121
(End) Manuela Zoccali [IA-PUC., Chile], Patricia Vannier [CDS] 22-Feb-2017