J/MNRAS/469/1330 NGC 6067 stars (Alonso-Santiago+, 2017)
NGC 6067: a young and massive open cluster with high metallicity.
Alonso-Santiago J., Negueruela I., Marco A., Tabernero H.M.,
Gonzalez-Fernandez C., Castro N.
<Mon. Not. R. Astron. Soc., 469, 1330-1353 (2017)>
=2017MNRAS.469.1330A 2017MNRAS.469.1330A (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Populations, stellar ; Abundances
Keywords: stars: abundances - stars: fundamental parameters -
Hertzsprung-Russell and colour-magnitude diagrams - stars: late-type -
stars: variables: Cepheids -
open clusters and associations: individual: NGC 6067
Abstract:
NGC 6067 is a young open cluster hosting the largest population of
evolved stars among known Milky Way clusters in the 50-150Ma age
range. It thus represents the best laboratory in our Galaxy to
constrain the evolutionary tracks of 5-7M☉ stars. We have used
high-resolution spectra of a large sample of bright cluster members
(45), combined with archival photometry, to obtain accurate parameters
for the cluster as well as stellar atmospheric parameters. We derive a
distance of 1.78±0.12 kpc, an age of 90±20Ma and a tidal radius of
14.8+6.8-3.2 arcmin. We estimate an initial mass above
5700M☉, for a present-day evolved population of two Cepheids,
two A supergiants and 12 red giants with masses ~=6M☉. We also
determine chemical abundances of Li, O, Na, Mg, Si, Ca, Ti, Ni, Rb, Y
and Ba for the red clump stars. We find a supersolar metallicity,
[Fe/H]=+0.19±0.05, and a homogeneous chemical composition,
consistent with the Galactic metallicity gradient. The presence of a
Li-rich red giant, star 276 with A(Li)=2.41, is also detected. An
overabundance of Ba is found, supporting the enhanced s-process. The
ratio of yellow to red giants is much smaller than 1, in agreement
with models with moderate overshooting, but the properties of the
cluster Cepheids do not seem consistent with current Padova models for
supersolar metallicity.
Description:
We obtained high-resolution echelle spectra using FEROS (Fibre
Extended Range Optical Spectrograph) mounted on the ESO/MPG 2.2-metre
telescope at the La Silla Observatory, in Chile. FEROS covers the
wavelength range from 3500 to 9200Å, providing a resolving power of
R=48000.
The spectra were taken during four consecutive nights in 2011 May
10-13 under programme 087.D-0603(A). The exposure times ranged from
600 to 4800s to achieve a typical signal-to-noise ratio (SNR) of
around S/N~=70-80 for blue stars in the classification region
(4000-5000Å) and S/N~=90-100 for the cool stars (6000-7000Å).
Later, in 2015 May, under programme 095.A-9020(A), we observed the
star HD 145175 (star 229 in Table 1) with the same instrument. To
complete our sample, we took from the ESO Archive Raw Data spectra of
QZ Nor, observed originally in 2007 under programme 060.A-9120(B). In
total, we have spectra for 48 stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 85 48 Log of the observed stars
table5.dat 66 31 Stellar atmospheric parameters for the hot stars
table6.dat 77 14 Stellar atmospheric parameters for the cool stars
table9.dat 125 15 Chemical abundances, relative to solar abundances
by Asplund et al. (2005, ASP Conf. Ser. 336, 25),
measured on the cool stars
tablea1.dat 96 48 Photometric magnitudes of the stars observed
spectroscopically
tablea2.dat 26 43 Number of red giant stars and yellow supergiants
in open clusters, containing no Cepheids,
with ages between 50 and 150Ma
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See also:
https://webda.physics.muni.cz : WEBDA database HomePage
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Star Star designation (1)
16- 25 F10.6 deg RAdeg Right ascension (J2000)
27- 36 F10.6 deg DEdeg Declination (J2000)
38- 50 A13 --- SpType Spectral type
54- 57 I4 s Texp Exposure time
59- 61 I3 --- SNR Signal-to-noise ratio
63- 68 F6.2 km/s RV Radial velocity
70- 74 F5.2 km/s e_RV rms uncertainty on radial velocity
76- 77 A2 --- Member [yn? ] Member ?
79- 85 A7 --- Notes Notes
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Note (1): Numbers are WEBDA identification numbers for NGC 6067 stars.
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Byte-by-byte Description of file: table5.dat table6.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Members [MN ] Member ?
4- 17 A14 --- Star Star designation
18 A1 --- n_Star [a] Note on Star (1)
19 A1 --- l_vsini Limit flag on vsini
20- 24 F5.1 km/s vsini Rotational velocity
26- 29 F4.1 km/s e_vsini ? rms uncertainty on rotational velocity
32 A1 --- l_Vtur Limit flag on Vtur
33- 38 F6.2 km/s Vtur Microturbulent velocity
40- 44 F5.2 km/s e_Vtur ? rms uncertainty on microturbulent velocity
46- 50 I5 K Teff Effective temperature
52- 55 I4 K e_Teff rms uncertainty on effective temperature
57 A1 --- l_logg Lower limit flag on logg
58- 61 F4.2 [cm/s2] logg Surface gravity
63- 66 F4.2 [cm/s2] e_logg ? rms uncertainty on surface gravity
67 A1 --- n_logg [b] Note on logg (2)
69- 72 F4.2 [-] [Fe/H] ? Metallicity (only in table6.dat)
74- 77 F4.2 [-] e_[Fe/H] ? rms uncertainty on metallicity
(only in table6.dat)
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Note (1): a: These objects are Be stars. In addition, stars 272 and 290 are
shell stars and these parameters do not correspond to the actual star,
but to the shell spectrum.
Note (2): b: For stars 261 and 275, the tabulated value of gravity is a lower
limit (these stars are close to the limit of the grid used).
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Members [MN ] Member ?
4- 17 A14 --- Star Star designation (1)
18- 22 F5.2 [Sun] [O/H] ? Abundance [O/H]
24- 27 F4.2 [Sun] e_[O/H] ? rms uncertainty on [O/H] abundance
29- 33 F5.2 [Sun] [Na/H] Abundance [Na/H]
35- 38 F4.2 [Sun] e_[Na/H] rms uncertainty on [Na/H] abundance
40- 44 F5.2 [Sun] [Mg/H] ? Abundance [Mg/H]
46- 49 F4.2 [Sun] e_[Mg/H] ? rms uncertainty on [Mg/H] abundance
51- 54 F4.2 [Sun] [Si/H] Abundance [Si/H]
56- 59 F4.2 [Sun] e_[Si/H] rms uncertainty on [Si/H] abundance
61- 65 F5.2 [Sun] [Ca/H] Abundance [Ca/H]
67- 70 F4.2 [Sun] e_[Ca/H] rms uncertainty on [Ca/H] abundance
72- 76 F5.2 [Sun] [Ti/H] Abundance [Ti/H]
78- 81 F4.2 [Sun] e_[Ti/H] rms uncertainty on [Ti/H] abundance
83- 87 F5.2 [Sun] [Ni/H] Abundance [Ni/H]
89- 92 F4.2 [Sun] e_[Ni/H] rms uncertainty on [Ni/H] abundance
94- 98 F5.2 [Sun] [Rb/H] ? Abundance [Rb/H]
100-103 F4.2 [Sun] e_[Rb/H] ? rms uncertainty on [Rb/H] abundance
105-109 F5.2 [Sun] [Y/H] ? Abundance [Y/H]
111-114 F4.2 [Sun] e_[Y/H] ? rms uncertainty on [Y/H] abundance
116-120 F5.2 [Sun] [Ba/H] ? Abundance [Ba/H]
122-125 F4.2 [Sun] e_[Ba/H] ? rms uncertainty on [Ba/H] abundance
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Note (1): "Mean" for mean values of the members stars.
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Star Star designation
15 A1 --- n_Star Note on Star (1)
17- 29 A13 --- CPD CPD name
31- 43 A13 --- SpType Spectral type
45- 50 F6.3 mag Bmag ? B magnitude (2)
52- 57 F6.3 mag Vmag ? V magnitude (2)
59- 64 F6.3 mag Jmag 2MASS J magnitude
66- 70 F5.3 mag e_Jmag 2MASS J magnitude error
72- 77 F6.3 mag Hmag 2MASS H magnitude
79- 83 F5.3 mag e_Hmag 2MASS H magnitude error
85- 90 F6.3 mag Ksmag 2MASS Ks magnitude
92- 96 F5.3 mag e_Ksmag 2MASS Ks magnitude error
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Note (1): a: For this star (276), there is a typographic error in the reference
paper. It has been corrected in this work by using directly the values from
Thackeray et al. (1962MNRAS.124..445T 1962MNRAS.124..445T)..
Note (2): Optical values are taken from An et al. (2007ApJ...671.1640A 2007ApJ...671.1640A).
The typical photometric error is 0.025mag.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Cluster Cluster name
17- 20 F4.2 [yr] logtau Age, taken from the WEBDA data base
(https://webda.physics.muni.cz)
22- 23 I2 --- NRG Number of red giants
26 A1 --- NYG ? Number of yellow supergiants
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 30-Mar-2020