J/MNRAS/464/194 Metallicity distribution in the GC (Feldmeier-Krause+, 2017)
KMOS view of the Galactic centre,
II. Metallicity distribution of late-type stars.
Feldmeier-Krause A., Kerzendorf W., Neumayer N., Schoedel R.,
Nogueras-Lara F., Do T., de Zeeuw P. T., Kuntschner H.
<Mon. Not. R. Astron. Soc. 464, 194 (2017)>
=2017MNRAS.464..194F 2017MNRAS.464..194F (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, late-type ; Abundances, [Fe/H] ;
Photometry, infrared
Keywords: stars: late-type - Galaxy: centre - infrared: stars
Abstract:
Knowing the metallicity distribution of stars in the Galactic Centre
has important implications for the formation history of the Milky Way
nuclear star cluster. However, this distribution is not well known,
and is currently based on a small sample of fewer than 100 stars. We
obtained near-infrared K-band spectra of more than 700 late-type stars
in the central 4pc2 of the Milky Way nuclear star cluster with the
integral-field spectrograph KMOS (VLT). We analyse the
medium-resolution spectra using a full-spectral fitting method
employing the Gottingen spectral library of synthetic PHOENIX spectra.
The derived stellar metallicities range from metal-rich [M/H]>+0.3dex
to metal-poor [M/H]←1.0dex, with a fraction of 5.2+6.0-3.1 per
cent metal-poor ([M/H]≤-0.5dex) stars. The metal-poor stars are
distributed over the entire observed field. The origin of metal-poor
stars remains unclear. They could originate from infalling globular
clusters. For the metal-rich stellar population ([M/H]>0dex), a
globular cluster origin can be ruled out. As there is only a very low
fraction of metal-poor stars in the central 4pc2 of the Galactic
Centre, we believe that our data can discard a scenario in which the
Milky Way nuclear star cluster is purely formed from infalling
globular clusters.
Description:
We obtained near-infrared K-band spectra of more than 700 late-type
stars in the central 4pc2 of the Milky Way nuclear star cluster with
the integral-field spectrograph KMOS (VLT). We analysed the medium-
resolution spectra using a full-spectral fitting method employing the
Goettingen Spectral library of synthetic PHOENIX spectra. We fitted
the spectra for the effective temperature, overall metallicity [M/H],
surface gravity log(g) and radial velocity vz. Here we present the
full table tableb1.dat from Appendix B.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 67 705 Table of stellar parameters
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See also:
J/A+A/511/A18 : NIR observations of stars near SgrA* (Schoedel+, 2010)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Id Identifation number,
[FNS2015] NNNNN in Simbad
7- 15 F9.5 deg RAdeg Right ascension (J2000)
17- 26 F10.6 deg DEdeg Declination (J2000)
28- 31 I4 K Teff Effective temperature
33- 35 I3 K e_Teff rms uncertainty of effective temperature
37- 41 F5.2 --- [M/H] Metallicity
43- 46 F4.2 --- e_[M/H] rms uncertainty of metallicity
48- 50 F3.1 [cm/s2] logg Surface gravity
52- 54 F3.1 [cm/s2] e_logg rms uncertainty of surface gravity
56- 61 F6.1 km/s RV Radial velocity in local standard of rest
63- 67 F5.2 mag Ksmag Ks-band magnitude (1)
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Note (1): Extinction corrected with map from Schoedel et al.
(2010A&A..511A..18S, Cat. J/A+A/511/A18) and Nogueras-Lara et al. (in prep).
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Acknowledgements:
Anja Feldmeier-Krause, afeldmei(at)uchicago.edu
(End) Anja Feldmeier-Krause [Univ. Chicago], Patricia Vannier [CDS] 21-Oct-2016