J/A+A/699/A246 Metallicities of old open clusters (Hu+, 2025)
Metallicities of old open clusters: A new Galactic map.
Hu Q, Soubiran C.
<Astron. Astrophys. 699, A246 (2025)>
=2025A&A...699A.246H 2025A&A...699A.246H (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Abundances, [Fe/H]
Keywords: stars: abundances - Galaxy: abundances - Galaxy: disk -
Galaxy: evolution - open clusters and associations: general
Abstract:
We determined precise and homogeneous metallicities for old open
clusters (≥500Myr) from all-sky catalogues of stellar parameters
leveraging Gaia spectrophotometry. Our purpose was to revisit the
metallicity distribution of the oldest open clusters as a function of
their Galactic position and age with improved statistics. Several
catalogues of stellar parameters have been cross-matched to the most
recent census of open clusters and their members. Median metallicities
per cluster and per catalogue were evaluated by comparison to
high-resolution spectroscopy. Our sample includes 1113 open clusters.
A typical precision of 0.05dex is achieved for a subsample of nearly
600 clusters when only their bright red giants are considered.
Metal-rich and metal-poor clusters never studied before are presented,
as well as remnants of dissolving clusters. Galactic maps show a
smooth decrease of metallicity from inside to outside the disc. We
measured the radial and vertical gradients, their evolution with time
and the age-metallicity relation in bins of Galactocentric distance.
Description:
The initial list of open clusters older than 500Myr has been selected
from Cavallo et al. (2024AJ....167...12C 2024AJ....167...12C, Cat. J/AJ/167/12). The list
of members, from Hunt & Reffert (2024A&A...686A..42H 2024A&A...686A..42H, Cat.
J/A+A/686/A42) and Cantat-Gaudin et al. (2018A&A...618A..93C 2018A&A...618A..93C, Cat.
J/A+A/618/A93), has been cross-matched to the catalogues of stellar
parameters from Anders et al. (2022A&A...658A..91A 2022A&A...658A..91A, Cat. I/354) ;
Andrae et al. (2023ApJS..267....8A 2023ApJS..267....8A); Zhang et al.
(2023MNRAS.524.1855Z 2023MNRAS.524.1855Z); Khalatyan et al. (2024A&A...691A..98K 2024A&A...691A..98K, Cat.
V/160); Fallows & Sanders (2024MNRAS.531.2126F 2024MNRAS.531.2126F). In each case we give
the median metallicity per cluster from at least 3 members in the Teff
range 4000-6500K, the corresponding median absolute deviation as the
uncertainty, and the number of considered members. For the case of
Andrae et al. (2023ApJS..267....8A 2023ApJS..267....8A), we give median metallicities
deduced from their full catalogue and from their vetted sample
of bright red giants.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 135 1113 Median metallicities of old open clusters from
different stellar catalogues
--------------------------------------------------------------------------------
See also:
I/354 : StarHorse2, Gaia EDR3 photo-astrometric dist. (Anders+, 2022)
V/160 : SHBoost 2024 (Khalatyan+, 2024)
J/A+A/618/A93 : Gaia DR2 open clusters in the Milky Way (Cantat-Gaudin+, 2018)
J/AJ/167/12 : Open cluster parameters with ANN (Cavallo+, 2024)
J/A+A/686/A42 : Improving the open cluster census. III. (Hunt+, 2024)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 21 A20 --- Cluster Cluster name adopted from Cavallo et al.,
(2024, Cat. J/AJ/167/12)
23- 30 F8.4 deg RAdeg Right Ascension (ICRS) at Ep=J2000
32- 39 F8.4 deg DEdeg Declination (ICRS) at Ep=J2000
41- 45 F5.2 --- MA22 ? Median metallicity from Anders et al.,
(2022, Cat. Cat. I/354)
47- 50 F4.2 --- e_MA22 ? Metallicity uncertainty
52- 55 I4 --- NA22 ? Number of considered members
57- 61 F5.2 --- MA23f Median metallicity from Andrae et al.,
(2023ApJS..267....8A 2023ApJS..267....8A) (1)
63- 66 F4.2 --- e_MA23f Metallicity uncertainty
68- 71 I4 --- NA23f Number of considered members
73- 77 F5.2 --- MA23g ? Median metallicity from Andrae et al.,
(2023ApJS..267....8A 2023ApJS..267....8A) (2)
79- 82 F4.2 --- e_MA23g ? Metallicity uncertainty
84- 87 I4 --- NA23g ? Number of considered members
89- 93 F5.2 --- MZ23 ? Median metallicity from Zhang et al.
(2023MNRAS.524.1855)
95- 98 F4.2 --- e_MZ23 ? Metallicity uncertainty
100-103 I4 --- NZ23 ? Number of considered members
105-109 F5.2 --- MK24 ? Median metallicity from Khalatyan et al.,
(2024, Cat. V/160)
111-114 F4.2 --- e_MK24 ? Metallicity uncertainty
116-119 I4 --- NK24 ? Number of considered members
121-125 F5.2 --- MF24 ? Median metallicity from Fallows et al.,
(2024MNRAS.531.2126F 2024MNRAS.531.2126F)
127-130 F4.2 --- e_MF24 ? Metallicity uncertainty
132-135 I4 --- NF24 ? Number of considered members
--------------------------------------------------------------------------------
Note (1): The full catalogue of Andrae et al. (2023ApJS..267....8A 2023ApJS..267....8A) has been
considered.
Note (2): Only the subsample of bright red giants from Andrae et al.
(2023ApJS..267....8A 2023ApJS..267....8A) has been considered.
--------------------------------------------------------------------------------
Acknowledgements:
Caroline Soubiran, caroline.soubiran(at)u-bordeaux.fr
(End) Patricia Vannier [CDS] 02-Jun-2025