J/MNRAS/513/5920 Stellar Populations of NSC and NSD (Feldmeier-Krause, 2022)
Stellar populations in the transition region of nuclear star cluster and
nuclear stellar disc.
Feldmeier-Krause A.
<Mon. Not. R. Astron. Soc., 513, 5920-5934 (2022)>
=2022MNRAS.513.5920F 2022MNRAS.513.5920F (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, late-type ; Infrared sources ;
Effective temperatures ; Radial velocities ; Abundances
Keywords: stars: late-type - Galaxy: centre - infrared: stars
Abstract:
The Milky Way nuclear star cluster (NSC) is located within the
nuclear stellar disc (NSD) in the Galactic Centre. It is not fully
understood if the formation and evolution of these two components are
connected, and how they influence each other. We study the stellar
populations in the transition region of NSC and NSD. We observed two
∼4.3pc2 fields with the integral-field spectrograph KMOS (VLT),
located at r∼20pc (>4Re) to the Galactic East and West of the NSC.
We extract and analyse medium-resolution stellar spectra of >200 stars
per field. The data contain in total nine young star candidates. We
use stellar photometry to estimate the stellar masses, effective
temperatures, and spectral types of the young stars. The stars are
consistent with an age of 4-6Myr, they may have formed inside the
Quintuplet cluster, but were dispersed in dynamical interactions. Most
stars in the two fields are red giant stars, and we measure their
stellar metallicities [M/H] using full spectral fitting. We compare
our [M/H] distributions to the NSC and NSD, using data from the
literature, and find that the overall metallicity decreases from the
central NSC, over the transition region, to the NSD. The steep
decrease of [M/H] from the NSC to the region dominated by the NSD
indicates that the two components have distinct stellar populations
and formation histories.
Description:
Our data were observed with KMOS on VLT-UT1 (Antu) 2014 June 7, and
2014 July 31 in service mode.
We obtained near-infrared K-band spectra of more than 400 late-type
stars located in two fields in the Galactic Center, at a distance of
20pc from the central supermassive black hole. The data were obtained
with the medium-resolution integral-field spectrograph KMOS (VLT). We
analysed the spectra using the full-spectral fitting code "starkit",
and the Goettingen Spectral library of synthetic PHOENIX spectra.
We derived the effective temperature, metallicity [M/H], surface
gravity log(g) and line-of-sight velocity vz.
Here we present the full table B.1 from Appendix B.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 109 505 Stellar parameters of our sample
(corrected table, 02-Aug-2023)
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See also:
II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)
II/295 : Spitzer IRAC survey of the galactic center (Ramirez+, 2008)
J/A+A/631/A20 : GALACTICNUCLEUS JHKs imaging survey. II. (Nogueras-Lara+, 2019)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 7 I7 --- Id Identification number
9- 17 F9.5 deg RAdeg Right ascension (J2000)
21- 30 F10.6 deg DEdeg Declination (J2000)
34- 37 I4 K Teff Effective temperature
41- 43 I3 K e_Teff Lower uncertainty of effective temperature
46- 48 I3 K E_Teff Upper uncertainty of effective temperature
51- 55 F5.2 [-] [M/H] Metallicity
59- 62 F4.2 [-] e_[M/H] Lower uncertainty of metallicity
65- 68 F4.2 [-] E_[M/H] Upper uncertainty of metallicity
70- 72 F3.1 [cm/s2] logg Surface gravity
75- 77 F3.1 [cm/s2] e_logg Lower uncertainty of surface gravity
79- 81 F3.1 [cm/s2] E_logg Upper uncertainty of surface gravity
83- 88 F6.1 km/s RV Radial velocity in local standard of rest
93- 96 F4.1 km/s e_RV Lower uncertainty of radial velocity
100-103 F4.1 km/s E_RV Upper uncertainty of radial velocity
105-109 F5.2 mag Ksmag0 Ks-band magnitude after extinction correction
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Acknowledgements:
Anja Feldmeier-Krause, feldmeier(at)mpia.de
History:
30-Aug-2022: in-line version
02-Aug-2023: table3 corrected (4 sources removed)
(End) Patricia Vannier [CDS] 29-Aug-2022