J/A+A/687/A124 Gaia-ESO data on Na, O in open clusters (Bragaglia+, 2024)
The Gaia-ESO Survey: No sign of multiple stellar populations in open clusters
from their sodium and oxygen abundances.
Bragaglia, A., D'Orazi, V., Magrin, L., Baratella M., Bensby T.,
Martell S.L., Randich S., Tautvaisiene G., Alfaro E.J., Morbidelli L.,
Smiljanic R., Zaggia S.
<Astron. Astrophys. 687, A124 (2024)>
=2024A&A...687A.124B 2024A&A...687A.124B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Radial velocities ; Optical ; Abundances
Keywords: techniques: radial velocities - techniques: spectroscopy -
stars: abundances - stars: kinematics and dynamics -
open clusters and associations: general
Abstract:
The light element (anti-)correlations shown by globular
clusters (GCs) are the main spectroscopic signature of multiple
stellar populations. These internal abundance variations provide us
with fundamental constraints on the formation mechanism of stellar
clusters.
Using Gaia-ESO, the largest and most homogeneous survey of open
clusters (OCs), we intend to check whether these stellar aggregates
display the same patterns. Based on previous studies of many GCs,
several young and massive clusters in the Magellanic Clouds, as well
as a few OCs, we do not expect to find any anti-correlation, given the
low mass of Milky Way OCs.
We used the results based on UVES spectra of stars in Gaia-ESO to
derive the distribution of Na and O abundances and see whether they
show an unexplained dispersion or whether they are anti-correlated. By
selecting only high-probability members with high-precision stellar
parameters, we ended up with more than 700 stars in 74 OCs. We
examined the O-Na distribution in 28 OCs with at least 4 stars
available as well as the Na distribution in 24 OCs, with at least 10
stars available.
We find that the distribution of Na abundances is compatible with a
single-value population, within the errors. The few apparent
exceptions can be explained by differences in the evolutionary phase
(main sequence and giant post first dredge-up episode) or by
difficulties in analysing low gravity giants. We did not find any
indication of an Na-O anti-correlation in any of the clusters for
which O has been derived.
Based on the very small spread we find, OCs maintain the status of
single stellar populations. However, a definitive answer requires
studying more elements and larger samples covering different
evolutionary phases. This will be possible with the next generation of
large surveys.
Description:
We used the public survey GES to study the possible presence of
star-to-star variations in the light elements O and Na.
Table A2 list the name of the cluster, Gaia DR3 identification, GES
object name, GES RV and error, Teff and error, log g and error,
metallicity, Na and O abundance with their errors, and Gaia DR3 RV
with error.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 117 82 Literature information on the observed clusters
tablea2.dat 125 734 Properties of the individual stars
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Cluster Cluster name
16- 17 I2 --- Nobs Number of observations
19- 22 F4.2 mag AV ?=- Absorption in V band (1)
24- 28 I5 pc Dist Distance (1)
30- 33 F4.2 [yr] logt log Age or lower value of logAge interval (1)
34 A1 --- --- [-]
35- 37 F3.1 [yr] logt2 ? Upper value of logAge interval
39- 43 F5.3 [Msun] logMass1 ? Mass from r_logMass1 reference
45 I1 --- r_logMass1 [1/2]? Reference for logMass1 (2)
47- 51 F5.3 [Msun] logMass2 ? Mass from r_logMass2 reference
53 I1 --- r_logMass2 [1/2]? Reference for logMass2 (2)
55- 61 F7.2 km/s RV ? Radial velocity
63- 66 F4.2 km/s e_RV ? Radial velocity standard error
68- 70 I3 --- N ? Number members used to derive them come from
Tarricq et al. (2021A&A...647A..19T 2021A&A...647A..19T,
Cat. J/A+A/647/A19)
72 A1 --- O? [Y/N] indicate whether oxygen was measured
in the cluster
74-117 A44 --- Name Alternative name (from Simbad)
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Note (1): from Cantat-Gaudin et al. (2020A&A...640A...1C 2020A&A...640A...1C, Cat. J/A+A/640/A1),
with a few exceptions (NGC 6530, Cha I, rho Oph, and gamma Vel) taken from
Randich et al. (2022A&A...666A.121R 2022A&A...666A.121R, Cat. J/A+A/666/A121)
Note (2): Note as follows:
1 = Ebrahimi et al. (2022MNRAS.516.5637E 2022MNRAS.516.5637E)
2 = Almeida et al. (2023MNRAS.525.2315A 2023MNRAS.525.2315A)
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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- 14 A14 --- Cluster Cluster name
16- 34 I19 --- GaiaDR3 Gaia DR3 source name
36- 51 A16 --- GES Gaia-ESO object name (HHMMSSss+DDMMSSs)
53- 58 F6.2 km/s RVGES ? Radial velocity Gaia-ESO
60- 63 F4.2 km/s e_RVGES ? Error on GES RV
65- 68 I4 K Teff Gaia-ESO effective temperature
70- 71 I2 K e_Teff Error on GES Teff
73- 76 F4.2 [cm/s2] logg Gaia-ESO surface gravity
78- 81 F4.2 [cm/s2] e_logg Error on GESlogg
83- 87 F5.2 --- [Fe/H] Metallicity
89- 92 F4.2 --- e_[Fe/H] Error on GES [Fe/H]
94- 97 F4.2 --- NaI ? log(Na) abundance
99-102 F4.2 --- e_NaI ? Error on GES NaI
104-107 F4.2 --- OI ? log(O) abundance
109-112 F4.2 --- e_OI ? Error on GES OI
114-119 F6.2 km/s RVGDR3 ? Gaia DR3 RV
121-125 F5.2 km/s e_RVGDR3 ? Error on GDR3 RV
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Acknowledgements:
Angela Bragaglia, angela.bragaglia(at)inaf.it
(End) Patricia Vannier [CDS] 13-Jun-2024