J/A+A/573/A55 Gaia-ESO Survey: Tr 20, NGC4815, NGC6705 (Tautvaisiene+, 2015)
The Gaia-ESO Survey: CNO abundances in the open clusters Trumpler 20, NGC 4815,
and NGC 6705.
Tautvaisiene G., Drazdauskas A., Mikolaitis S., Barisevicius G.,
Puzeras E., Stonkute E., Chorniy Y., Magrini L., Romano D., Smiljanic R.,
Bragaglia A., Carraro G., Friel E., Morel T., Pancino E., Donati P.,
Jimenez-Esteban F., Gilmore G., Randich S., Jeffries R.D., Vallenari A.,
Bensby T., Flaccomio E., Recio-Blanco A., Costado M.T., Hill V., Jofre P.,
Lardo C., De Laverny P., Masseron T., Moribelli L., Sousa S.G., Zaggia S.
<Astron. Astrophys., 573, A55-55 (2015)>
=2015A&A...573A..55T 2015A&A...573A..55T (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Radial velocities ; Rotational velocities
Keywords: stars: abundances - stars: evolution - Galaxy: evolution -
open clusters and associations: individual: Trumpler 20 -
open clusters and associations: individual: NGC4815 -
open clusters and associations: individual: NGC6705
Abstract:
The Gaia-ESO Public Spectroscopic Survey will observe a large sample
of clusters and cluster stars, covering a wide
age-distance-metallicity-position-density parameter space.
We aim to determine C, N, and O abundances in stars of Galactic open
clusters of the Gaia-ESO survey and to compare the observed abundances
with those predicted by current stellar and Galactic evolution models.
In this pilot paper, we investigate the first three intermediate-age
open clusters.
High-resolution spectra, observed with the FLAMES-UVES spectrograph on
the ESO VLT, were analysed using a differential model atmosphere
method. Abundances of carbon were derived using the C2 band heads at
5135 and 5635.5Å. The wavelength interval 6470-6490Å, with CN
features, was analysed to determine nitrogen abundances. Oxygen
abundances were determined from the [OI] line at 6300Å.
The mean values of the elemental abundances in Trumpler 20 as
determined from 42 stars are: [Fe/H]=0.10±0.08 (s.d.),
[C/H]=-0.10±0.07, [N/H]=0.50±0.07, and consequently
C/N=0.98±0.12. We measure from five giants in NGC 4815:
[Fe/H]=-0.01±0.04, [C/H]=-0.17±0.08, [N/H]=0.53±0.07,
[O/H]=0.12±0.09, and C/N=0.79±0.08. We obtain from 27 giants in
NGC 6705: [Fe/H]=0.0±0.05, [C/H]=-0.08±0.06, [N/H]=0.61±0.07,
[O/H]=0.13±0.05, and C/N=0.83±0.19. The C/N ratios of stars in the
investigated open clusters were compared with the ratios predicted by
stellar evolutionary models. For the corresponding stellar turn-off
masses from 1.9 to 3.3M☉, the observed C/N ratio values are very
close to the predictions of standard first dredge-up models as well as
to models of thermohaline extra-mixing. They are not decreased as much
as predicted by the recent model in which the thermohaline- and
rotation-induced extra-mixing act together. The average [O/H]
abundance ratios of NGC 4815 and NGC 6705 are compared with the
predictions of two Galactic chemical evolution models. The data are
consistent with the evolution at the solar radius within the errors.
The first results of CNO determinations in open clusters show the
potential of the Gaia-ESO Survey to judge stellar and Galactic
chemical evolution models and the validity of their physical
assumptions through a homogeneous and detailed spectral analysis.
Description:
Observations were conducted with the FLAMES (Fiber Large Array
Multi-Element Spectrograph) multi-fiber facility in spring of 2012 and
2013. Spectra of high-resolving power (R∼47000) were obtained
with UVES (Ultraviolet and Visual Echelle Spectrograph) The spectra
were exposed onto two CCDs, resulting in a wavelength coverage of
4700-6840Å with a gap of about 50Å in the centre.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 81 42 Stellar parameters for target stars in Trumpler 20
table2.dat 81 5 Stellar parameters for target stars in NGC 4815
table3.dat 81 27 Stellar parameters for target stars in NGC 6705
table5.dat 60 42 Main atmospheric parameters and elemental abundances
for stars in the open cluster Trumpler 20
table6.dat 60 5 Main atmospheric parameters and elemental abundances
for stars in the open cluster NGC 4815
table7.dat 60 27 Main atmospheric parameters and elemental abundances
for stars in the open cluster NGC 6705
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See also:
J/MNRAS/310/982 : UBVI CCD Photometry of M11 - II. (Sung+ 1999)
Byte-by-byte Description of file: table1.dat table2.dat table3.dat
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Bytes Format Units Label Explanations
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1 I1 --- Ref [1/3] Reference (1)
3- 6 I4 --- ID Identification number from reference
8- 23 A16 --- GES GES ID (HHMMSSss+DDMMSSs),
GES JHHMMSSss+DDMMSSs in Simbad
25- 32 F8.4 deg RAdeg Right ascension (J2000)
34- 41 F8.4 deg DEdeg Declination (J2000)
43- 48 F6.3 mag Vmag V magnitude
50- 54 F5.3 mag B-V ? B-V colour index
56- 60 F5.3 mag V-I ? V-I colour index
62- 67 F6.2 km/s RV Radial velocity
69- 71 I3 --- S/N Signal-to-noise ratio
73- 76 F4.2 km/s vinsiG GES database value of rotational velocity
78- 81 F4.1 km/s vsini Rotational velocity determined in this work
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Note (1): References as follows:
1 = ID and photometric data were taken from Carraro et al.
(2010AJ....140..954C 2010AJ....140..954C)
2 = V and V-I were taken from Prisinzano et al. (2001A&A...369..851P 2001A&A...369..851P)
3 = ID and photometric data were taken from Sung et al. (1999,
Cat. J/MNRAS/310/982, Cl* NGC 6705 SBL NNNNNN in Simbad)
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Byte-by-byte Description of file: table5.dat table6.dat table7.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- GES GES designation
17 A1 --- n_GES [*] Note on GES (1)
19- 22 I4 K Teff Effective temperature
24- 27 F4.2 [cm/s2] logg Surface gravity
29- 32 F4.2 km/s vt Microturbulent velocity
34- 38 F5.2 [-] [Fe/H] Metallicity (2)
40- 44 F5.2 [-] [C/H] Abundance [C/H] (2)
46- 49 F4.2 [-] [N/H] ? Abundance [N/H] (2)
51- 55 F5.2 [-] [O/H] ? Abundance [O/H] (2)
57- 60 F4.2 --- C/N ? Abundance C/N (2)
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Note (1): *: This star is a subgiant located close to the main sequence turn-off
and had no CN bands strong enough for the nitrogen abundance determination.
Note (2): Mean values:
Trumpler 20 NGC 4815 NGC 6705
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[Fe/H] 0.10±0.08 -0.01±0.04 0.00±0.05
[C/H] -0.10±0.10 -0.17±0.08 -0.08±0.06
[N/H] 0.50±0.07 0.53±0.07 0.61±0.07
[O/H] 0.12±0.09 0.13±0.05
C/N 0.98±0.12 0.79±0.08 0.83±0.19
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History:
* 15-Jan-2016: From electronic version of the journal, tables 1-3
* 13-Jun-2016: tables 5-7 added
(End) Patricia Vannier [CDS] 14-Dec-2015