J/MNRAS/514/4816 50 giant cluster stars abund. study (Katime Santrich+, 2022)
On the validity of the spectroscopic age indicators [Y/Mg], [Y/Al], [Y/Si],
[Y/Ca], and [Y/Ti] for giant stars.
Katime Santrich O.J., Kerber L., Abuchaim Y., Goncalves G.
<Mon. Not. R. Astron. Soc. 514, 4816-4827 (2022)>
=2022MNRAS.514.4816K 2022MNRAS.514.4816K (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, giant ; Clusters, open ; Spectroscopy ;
Photometry ; Optical ; Abundances ; Effective temperatures
Keywords: stars: abundances - stars: fundamental parameters - stars: late-type -
Galaxy: evolution - open clusters and associations: general
Abstract:
The abundance ratios [Y/Mg], [Y/Al], [Y/Si], [Y/Ca], and [Y/Ti] have
been suggested as chemical clocks for solar-metallicity dwarf stars in
the field as well as for giant stars in open clusters. To verify this
last hypothesis, we derive these abundances ratios of 50 giant stars
belonging to seven open clusters. To calculate the abundances, we
analyse FEROS spectra assuming the LTE-hypothesis. We confirm that
[Y/Mg], [Y/Al], [Y/Si], [Y/Ca], and [Y/Ti] work as chemical clocks for
field dwarf stars at the local region (d < 1 kpc) whereas for the
field giants the [Y/Mg], [Y/Al], and [Y/Si] also present trends with
the ages but high scattering. [Y/Ca] and [Y/Ti] do not present any
correlation with ages in the field giants. In our open clusters, the
behaviour is similar, [Y/Mg], [Y/Al], and [Y/Si] present evident
trends, whereas [Y/Ca] versus ages is a flat and [Y/Ti] versus ages
is less steep. We also confirm that the chemical clocks have high
scatter at the early ages. In the case of the compiled sample, the
chemical clocks are similar to our results but in some situations
there are important differences. Several relations between abundance
ratios and ages may be obtained when dwarfs and giants are analysed,
confirming the non-universality of the spectroscopic age indicators.
Description:
The spectroscopic ratios as [Y/Mg], [Y/Al] and others have been
important in last years owing to possibility to obtain reliable ages
for the stars. This fact is striking because stellar ages are hard to
derive and have always been a topic of discussion in astrophysics.
These spectroscopic clocks have been studied in field dwarf stars,
while in giants the results are limited for some open clusters. Thus,
we have applied a detailed spectroscopic analysis for 50 giant stars
in seven open clusters which have solar-like metallicities and ages
ranging from 150 Myr to 3.6 Gyr.
In order to calculate the chemical abundances and age indicators, we
used high-resolution spectra obtained with FEROS spectrograph
(installed on MPI 2.2 mts telescope in La Silla/Chile) having high
resolution and a wavelength coverage of [3800, 9200]Å. Using
GaiaDR2 catalogs we regroup in table2.dat the positional and
photometric informations of these 50 giant stars. Next, as explained
in section 3, we applied the LTE approximation to derive the abundance
ratios in the cluster sample. All abundances were obtained via EWs
measurements, with the exception of Ba and Eu that were computed via
spectral synthesis technique. To measure the EQW, we used the Gaussian
fits. The prerequisite SAP parameters to obtain abundances are
presented in the table5.dat. Then table6.dat and table7.dat regroup
our abundance ratios results for the 50 giant stars. Finally, as
explicited in section 4, we retained [Y/Mg], [Y/Al], [Y/Si], [Y/Ca],
and [Y/Ti] in order to correlate to star ages via linear least
square regression. The table9.dat contains all these abundance ratios
for the 50 giant stars.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
cluster.dat 10 7 Open cluster in our sample
table2.dat 68 50 Positional and photometric informations of the
giant stars sample in the seven open clusters
table5.dat 56 43 Stellar atmospheric parameters calculated from
our spectroscopic analysis work
table6.dat 87 43 *Abundance ratios [X/Fe] for the elements
calculated from our spectroscopic analysis and
EWs measurements work
table7.dat 56 7 *Abundance ratios for Mg, Al, Si, Ca, Ti, Sr,
Ba, and Eu in the cluster IC4651
table9.dat 42 50 *Chemical clocks in the seven open clusters
sample
--------------------------------------------------------------------------------
Note on table6.dat and table7.dat: These ratios were calculated from our
spectroscopic analysis and EWs measurements work, with [X/Fe] = [X/H] - [Fe/H]
and [X/H] = log(NX/NH)* - log(NX/NH)☉.
Note on table9.dat: The ratios were obtained from the definition
[a/b] = log(Na/Nb)* - log(Na/Nb)☉.
--------------------------------------------------------------------------------
See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/618/A93 : Gaia DR2 open clusters in the Milky Way
(Cantat-Gaudin+, 2018)
J/A+A/562/A71 : Chemical abundances of solar neighbourhood dwarfs
(Bensby+, 2014)
J/A+A/624/A78 : Masses and ages of 1059 HARPS-GTO stars (Delgado Mena+,2019)
J/A+A/631/A171 : Neutron-capture elements in dwarf galaxies
(Skuladottir+, 2019)
J/A+A/623/A108 : Age of 269 GDR2 open clusters (Bossini+, 2019)
J/A+A/433/185 : Detailed abundance analysis of 102 F and G dwarfs
(Bensby+, 2005)
J/A+A/639/A127 : Age-chemical-clocks-metallicity relations (Casali+, 2020)
J/A+A/652/A25 : Abundance-age relations with open clusters
(Casamiquela+, 2021)
J/A+A/616/A10 : 46 open clusters GaiaDR2 HR diagrams
(Gaia Collaboration, 2018)
J/AJ/150/88 : Abundances in the local region. I. G and K giants
(Luck, 2015)
J/AJ/155/111 : Abundances in the local region. III. Southern dwarfs
(Luck, 2018)
J/AJ/136/375 : Chemical composition of LMC red giants (Mucciarelli+, 2008)
J/ApJ/854/184 : Abundances of stars in 3 open clusters (Pena Suarez+, 2018)
J/MNRAS/474/2580 : Temporal evolution of neutron-capture elements
(Spina+, 2018)
J/MNRAS/419/1350 : Red giants abundances in 4 open clusters (Reddy+, 2012)
J/MNRAS/431/3338 : Abundances of red giants in open clusters (Reddy+, 2013)
J/MNRAS/450/4301 : Line list for red giants in open clusters (Reddy+, 2015)
J/MNRAS/485/3623 : Red giants abundance analysis in open clusters
(Reddy+, 2019)
https://doi.eso.org/10.18727/archive/24 : FEROS reduced spectra
Byte-by-byte Description of file: cluster.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Cluster Open cluster name (Cluster)
9- 10 I2 --- Nbr Number of star in the cluster (Nbr)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Star identification name as
ClusterName-NNNNN (Star)
14- 32 I19 --- GaiaDR2 Gaia DR2 identification source (GaiaDR2-ID)
34- 35 I2 h RAh Right ascension (J2000)
37- 38 I2 min RAm Right ascension (J2000)
40- 44 F5.2 s RAs Right ascension (J2000)
46 A1 --- DE- Declination sign (J2000)
47- 48 I2 deg DEd Declination (J2000)
50- 51 I2 arcmin DEm Declination (J2000)
53- 57 F5.2 arcsec DEs Declination (J2000)
59- 63 F5.2 mag Vmag Apparent AB magnitude in the optical
V-band (V)
65- 68 F4.2 mag B-V B-V optical colour index (B-V)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Star Star identification name as ClusterName-NNNNN
(Star)
13- 16 I4 K Teff Mean effective temperature derived from SAP
spectroscopic analysis (Teff) (1)
18- 19 I2 K e_Teff Standard deviation/error of the Teff derived
from SAP spectroscopic analysis (σTeff)
21- 24 F4.2 [cm/s2] logg Logarithm of the surface gravity derived from
SAP spectroscopic analysis (logg) (2)
26- 29 F4.2 [cm/s2] e_logg Standard deviation/error of the logg
(σlogg)
31- 34 F4.2 km/s vt Microturbulence velocity derived from SAP
spectroscopic analysis (Ξ) (3)
36- 39 F4.2 km/s e_vt Standard deviation/error of the vt (σvt)
41- 45 F5.2 [Sun] [Fe/H] Iron to hydrogen abundance ratio ([Fe/H]) (4)
47- 50 F4.2 [Sun] e_[Fe/H] Standard deviation/error of the [Fe/H]
(σ[Fe/H])
52- 53 I2 --- NFeI The number of Fe I lines used in the
spectroscopic analysis (#1)
55- 56 I2 --- NFeII The number of Fe II lines used in the
spectroscopic analysis (#2)
--------------------------------------------------------------------------------
Note (1): Mean Teff values for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
5060 ± 67 K, 4980 ± 84 K, 5099 ± 33 K, 5029 ± 155 K,
4569 ± 119 K and 4967 ± 104 K.
Note (2): Mean logg values for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
2.89 ± 0.10 [cm/s2], 2.75 ± 0.13[cm/s2], 3.03 ± 0.06[cm/s2],
2.75 ± 0.25 [cm/s2], 1.66 ± 0.18 [cm/s2] and 2.90 ± 0.14[cm/s2].
Note (3): Mean Ξ values for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
1.68 ± 0.03 km/s, 1.66 ± 0.04 km/s, 1.63 ± 0.04 km/s,
1.67 ± 0.09 km/s, 2.39 ± 0.15 km/s, 1.70 ± 0.05 km/s.
Note (4): Mean [Fe/H] values for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
-0.01 ± 0.02 [Sun], 0.00 ± 0.02 [Sun], 0.12 ± 0.01 [Sun],
0.03 ± 0.04 [Sun], -0.09 ± 0.04 [Sun], 0.08 ± 0.01 [Sun].
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Star Star identification name as ClusterName-NNNNN
(Star)
13- 17 F5.2 [Sun] [Mg/Fe] Magnesium to iron abundance ratio ([Mg/Fe]) (1)
19- 23 F5.2 [Sun] [Al/Fe] Aluminium to iron abundance ratio ([Al/Fe]) (2)
25- 29 F5.2 [Sun] [Si/Fe] Silicium to iron abundance ratio ([Si/Fe]) (3)
31- 35 F5.2 [Sun] [Ca/Fe] Calcium to iron abundance ratio ([Ca/Fe]) (4)
37- 41 F5.2 [Sun] [Ti/Fe] Titanium to iron abundance ratio ([Ti/Fe]) (5)
43- 47 F5.2 [Sun] [Sr/Fe] Strontium to iron abundance ratio ([Sr/Fe]) (6)
49- 53 F5.2 [Sun] [Y/Fe] Yttrium to iron abundance ratio ([Y/Fe]) (7)
55- 59 F5.2 [Sun] [Zr/Fe] Zirconium to iron abundance ratio ([Zr/Fe]) (8)
61- 65 F5.2 [Sun] [Ba/Fe] Barium to iron abundance ratio ([Ba/Fe]) (9)
67- 70 F4.2 [Sun] [La/Fe] Lanthanum to iron abundance ratio ([La/Fe])
(10)
72- 76 F5.2 [Sun] [Ce/Fe] Cerium to iron abundance ratio ([Ce/Fe]) (11)
78- 82 F5.2 [Sun] [Nd/Fe] Neodymium to iron abundance ratio ([Nd/Fe])
(12)
84- 87 F4.2 [Sun] [Eu/Fe] ? Europium to iron abundance ratio ([Eu/Fe])
(13)
--------------------------------------------------------------------------------
Note (1): Mean [Mg/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
-0.01 ± 0.02, 0.12 ± 0.02, 0.08 ± 0.01, -0.06 ± 0.04,
0.07 ± 0.04 and 0.10 ± 0.02.
Note (2): Mean [Al/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.10 ± 0.02, 0.11 ± 0.03, 0.12 ± 0.02, 0.08 ± 0.03,
0.21 ± 0.02, 0.16 ± 0.01.
Note (3): Mean [Si/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.12 ± 0.02, 0.08 ± 0.01, 0.11 ± 0.02, 0.01 ± 0.02,
0.06 ± 0.03, 0.18 ± 0.04.
Note (4): Mean [Ca/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.08 ± 0.01, 0.06 ± 0.01, 0.08 ± 0.02, 0.04 ± 0.03,
-0.11 ± 0.01, 0.04 ± 0.01.
Note (5): Mean [Ti/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.01 ± 0.01, 0.05 ± 0.01, 0.02 ± 0.01, -0.04 ± 0.02,
-0.13 ± 0.02, 0.06 ± 0.02.
Note (6): Mean [Sr/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.05 ± 0.02, 0.02 ± 0.02, 0.14 ± 0.03, 0.11 ± 0.04,
-0.02 ± 0.04, 0.01 ± 0.04.
Note (7): Mean [Y/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.12 ± 0.01, 0.08 ± 0.03, 0.10 ± 0.03, 0.04 ± 0.01,
0.05 ± 0.02, 0.03 ± 0.00
Note (8): Mean [Zr/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
-0.06 ± 0.03, 0.01 ± 0.03, 0.03 ± 0.03, -0.15 ± 0.02,
-0.11 ± 0.05, -0.03 ± 0.03
Note (9): Mean [Ba/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.13 ± 0.02, 0.31 ± 0.02, 0.15 ± 0.01, 0.23 ± 0.04,
0.12 ± 0.07, 0.05 ± 0.05
Note (10): Mean [La/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.33 ± 0.04, 0.34 ± 0.02, 0.26 ± 0.02, 0.20 ± 0.02,
0.12 ± 0.06, 0.19 ± 0.02
Note (11): Mean [Ce/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.16 ± 0.02, 0.24 ± 0.01, 0.17 ± 0.02, 0.02 ± 0.02,
-0.02 ± 0.04, 0.05 ± 0.01
Note (12): Mean [Nd/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.17 ± 0.03, 0.22 ± 0.03, 0.20 ± 0.02, 0.06 ± 0.04,
0.07 ± 0.09, 0.11 ± 0.03
Note (13): Mean [Eu/Fe] for the six open clusters IC4756, NGC5822, NGC6940,
NGC6633, NGC5316 and NGC2682 of our sample are respectively
0.11 ± 0.01, 0.12 ± 0.02, 0.10 ± 0.02, 0.11 ± 0.01,
0.10 ± 0.03, 0.15 ± 0.01
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Star identification name as ClusterName-NNNNN
(Star)
14- 17 F4.2 [Sun] [Mg/Fe] Magnesium to iron abundance ratio ([Mg/Fe]) (1)
19- 22 F4.2 [Sun] [Al/Fe] Aluminium to iron abundance ratio ([Al/Fe]) (2)
24- 28 F5.2 [Sun] [Si/Fe] Silicium to iron abundance ratio ([Si/Fe]) (3)
30- 34 F5.2 [Sun] [Ca/Fe] Calcium to iron abundance ratio ([Ca/Fe]) (4)
36- 40 F5.2 [Sun] [Ti/Fe] Titanium to iron abundance ratio ([Ti/Fe]) (5)
42- 46 F5.2 [Sun] [Sr/Fe] Strontium to iron abundance ratio ([Sr/Fe]) (6)
48- 51 F4.2 [Sun] [Ba/Fe] Barium to iron abundance ratio ([Ba/Fe]) (7)
53- 56 F4.2 [Sun] [Eu/Fe] Europium to iron abundance ratio ([Eu/Fe]) (8)
--------------------------------------------------------------------------------
Note (1): Mean [Mg/Fe] value is 0.06 ± 0.01.
Note (2): Mean [Al/Fe] value is 0.18 ± 0.02.
Note (3): Mean [Si/Fe] value is 0.12 ± 0.04.
Note (4): Mean [Ca/Fe] value is 0.01 ± 0.04.
Note (5): Mean [Ti/Fe] value is 0.00 ± 0.04.
Note (6): Mean [Sr/Fe] value is -0.02 ± 0.02.
Note (7): Mean [Ba/Fe] value is 0.08 ± 0.03.
Note (8): Mean [Eu/Fe] value is 0.14 ± 0.01.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Star identification name as ClusterName-NNNNN
(Star)
14- 18 F5.2 --- [Y/Mg] Yttrium to Magnesium abundance ratio ([Y/Mg])
(1)
20- 24 F5.2 --- [Y/Al] Yttrium to Aluminium abundance ratio ([Y/Al])
(2)
26- 30 F5.2 --- [Y/Si] Yttrium to Silicium abundance ratio ([Y/Si])
(3)
32- 36 F5.2 --- [Y/Ca] Yttrium to Calcium abundance ratio ([Y/Ca])
(4)
38- 42 F5.2 --- [Y/Ti] Yttrium to Titanium abundance ratio ([Y/Ti])
(5)
--------------------------------------------------------------------------------
Note (1): Mean [Y/Mg] for the seven clusters IC4756, IC4651, NGC6940,
NGC5822, NGC6633, NGC5316, NGC2682 of our sample are respectively
0.12 ± 0.02, 0.05 ± 0.04, 0.02 ± 0.03, -0.04 ± 0.04,
0.10 ± 0.03, -0.02 ± 0.04, -0.07 ± 0.01.
Note (2): Mean [Y/Al] for the seven clusters IC4756, IC4651, NGC6940,
NGC5822, NGC6633, NGC5316, NGC2682 of our sample are respectively
0.02 ± 0.03, 0.00 ± 0.04, -0.02 ± 0.03, -0.04 ± 0.04,
-0.04 ± 0.04, -0.15 ± 0.02, -0.13 ± 0.01.
Note (3): Mean [Y/Si] for the seven clusters IC4756, IC4651, NGC6940,
NGC5822, NGC6633, NGC5316, NGC2682 of our sample are respectively
-0.01 ± 0.02, 0.03 ± 0.03, 0.00 ± 0.03, 0.00 ± 0.03,
0.04 ± 0.03, -0.01 ± 0.01, -0.15 ± 0.03.
Note (4): Mean [Y/Ca] for the seven clusters IC4756, IC4651, NGC6940,
NGC5822, NGC6633, NGC5316, NGC2682 of our sample are respectively
0.03 ± 0.01, 0.15 ± 0.03, 0.03 ± 0.03, 0.02 ± 0.02,
0.01 ± 0.03, 0.16 ± 0.02, -0.01 ± 0.04.
Note (5): Mean [Y/Ti] for the seven clusters IC4756, IC4651, NGC6940,
NGC5822, NGC6633, NGC5316, NGC2682 of our sample are respectively
0.10 ± 0.01, 0.17 ± 0.02, 0.09 ± 0.02, 0.03 ± 0.03,
0.08 ± 0.02, 0.18 ± 0.04, -0.03 ± 0.03.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 11-Apr-2025