J/A+A/635/A8 Differential abundances of open clusters (Casamiquela+, 2020)
Differential abundances of open clusters and their tidal tails:
chemical tagging and chemical homogeneity,
Casamiquela L., Tarricq Y., Soubiran C., Blanco-Cuaresma S., Jofre P.,
Heiter U., Tucci Maia M.
<Astron. Astrophys. 635, A8 (2020)>
=2020A&A...635A...8C 2020A&A...635A...8C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Abundances
Keywords: stars: abundances - techniques: spectroscopic -
open clusters and associations: individual: NGC 2632 -
open clusters and associations: individual: Hyades -
open clusters and associations: individual: Ruprecht 147
Abstract:
Well studied Open Clusters (OCs) of the Solar neighbourhood are
frequently used as reference objects to test galactic and stellar
theories. For that purpose their chemical composition needs to be
known with a high level of confidence. It is also important to clarify
if each OC is chemically homogeneous and if it has a unique chemical
signature.
The aims of this work are (1) to determine accurate and precise
abundances of 22 chemical species (from Na to Eu) in the Hyades,
Praesepe and Rupecht 147 using a large number of stars at different
evolutionary states, (2) to evaluate the level of chemical homogeneity
of these OCs, (3) to compare their chemical signatures.
We gathered ∼800 high resolution and high signal-to-noise spectra of
∼100 members in the three clusters, obtained with the latest
memberships based on Gaia DR2 data. We build a pipeline which computes
atmospheric parameters and strictly line-by-line differential
abundances among twin stars in our sample. With this method we are
able to reach a very high precision in the abundances (0.01-0.02dex
in most of the elements).
We find large differences in the absolute abundances in some elements,
which can be attributed to diffusion, NLTE effects or systematics in
the analysis. For the three OCs, we find strong correlations in the
differential abundances between different pairs of elements. According
to our experiment with synthetic data, this can be explained by some
level of chemical inhomogeneity. We compare differential abundances of
several stars from the Hyades and Praesepe tails: the stars that
differ more in chemical abundances also have distinct kinematics, even
though they have been identified as members of the tail.
It is possible to obtain high precision abundances using a
differential analysis even when mixing spectra from different
instruments. With this technique we find that the Hyades and Preasepe
have the same chemical signature when G dwarfs and K giants are
considered. Despite a certain level of inhomogeneity in each cluster,
it is still possible to clearly distinguish the chemical signature of
the older cluster Ruprecht 147 when compared to the Hyades and
Praesepe.
Description:
Results of the spectroscopic analysis (velocities, atmospheric
parameters, absolute and differential abundances) of cluster stars and
the abundance results for the analyzed Gaia Benchmark stars. The high
resolution spectra analyzed come from either archival data (UVES,
FEROS, HARPS, FIES, ESPaDOnS, NARVAL, ELODIE spectrographs) and new
observing programs with NARVAL during two semesters (2018B and 2019A).
We also include the used line list.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 35 339 Line list selection
tablea1.dat 502 16 Individual abundances of the Gaia Benchmark
stars (TableA1 and TableA2 of the paper)
tablea3.dat 2172 108 Results of the cluster stars
--------------------------------------------------------------------------------
See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.3 0.1nm lambda Central wavelength of the line
10- 13 A4 --- El Chemical element with ionization state
15- 19 F5.3 eV EP Excitation potential of the transition
21- 26 F6.3 [-] loggf Oscillator strength
28- 35 A8 --- Group Star group for which the line was used (1)
--------------------------------------------------------------------------------
Note (1): Star groups as follows:
GI = giants
HD = F dwarfs
CD = G dwarfs
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Star Star name
11- 18 A8 --- HIP Hipparcos ID (HIPNNNNN)
20- 21 I2 --- Nspec Number of spectra analyzed
23- 27 F5.2 --- [NaI/H] NaI abundance with respect to the Sun
29- 32 F4.2 --- e_[NaI/H] NaI abundance uncertainty computed as the
dispersion among individual spectra
34- 37 F4.2 --- e_[NaI/H]m Median of the NaI abundance uncertainties
quoted for the individual spectra
39- 43 F5.2 --- [MgI/H] MgI abundance with respect to the Sun
45- 48 F4.2 --- e_[MgI/H] MgI abundance uncertainty computed as the
dispersion among individual spectra
50- 53 F4.2 --- e_[MgI/H]m Median of the MgI abundance uncertainties
quoted for the individual spectra
55- 59 F5.2 --- [AlI/H] AlI abundance with respect to the Sun
61- 64 F4.2 --- e_[AlI/H] AlI abundance uncertainty computed as the
dispersion among individual spectra
66- 69 F4.2 --- e_[AlI/H]m Median of the AlI abundance uncertainties
quoted for the individual spectra
71- 75 F5.2 --- [SiI/H] SiI abundance with respect to the Sun
77- 80 F4.2 --- e_[SiI/H] SiI abundance uncertainty computed as the
dispersion among individual spectra
82- 85 F4.2 --- e_[SiI/H]m Median of the SiI abundance uncertainties
quoted for the individual spectra
87- 91 F5.2 --- [CaI/H] CaI abundance with respect to the Sun
93- 96 F4.2 --- e_[CaI/H] CaI abundance uncertainty computed as the
dispersion among individual spectra
98-101 F4.2 --- e_[CaI/H]m Median of the CaI abundance uncertainties
quoted for the individual spectra
103-107 F5.2 --- [ScII/H] ScII abundance with respect to the Sun
109-112 F4.2 --- e_[ScII/H] ScII abundance uncertainty computed as the
dispersion among individual spectra
114-117 F4.2 --- e_[ScII/H]m Median of the ScII abundance uncertainties
quoted for the individual spectra
119-123 F5.2 --- [TiI/H] TiI abundance with respect to the Sun
125-128 F4.2 --- e_[TiI/H] TiI abundance uncertainty computed as the
dispersion among individual spectra
130-133 F4.2 --- e_[TiI/H]m Median of the TiI abundance uncertainties
quoted for the individual spectra
135-139 F5.2 --- [TiII/H] TiII abundance with respect to the Sun
141-144 F4.2 --- e_[TiII/H] TiII abundance uncertainty computed as the
dispersion among individual spectra
146-149 F4.2 --- e_[TiII/H]m Median of the TiII abundance uncertainties
quoted for the individual spectra
151-155 F5.2 --- [VI/H] VI abundance with respect to the Sun
157-160 F4.2 --- e_[VI/H] VI abundance uncertainty computed as the
dispersion among individual spectra
162-165 F4.2 --- e_[VI/H]m Median of the VI abundance uncertainties
quoted for the individual spectra
167-171 F5.2 --- [CrI/H] CrI abundance with respect to the Sun
173-176 F4.2 --- e_[CrI/H] CrI abundance uncertainty computed as the
dispersion among individual spectra
178-181 F4.2 --- e_[CrI/H]m Median of the CrI abundance uncertainties
quoted for the individual spectra
183-187 F5.2 --- [MnI/H] MnI abundance with respect to the Sun
189-192 F4.2 --- e_[MnI/H] MnI abundance uncertainty computed as the
dispersion among individual spectra
194-197 F4.2 --- e_[MnI/H]m Median of the MnI abundance uncertainties
quoted for the individual spectra
199-203 F5.2 --- [FeI/H] FeI abundance with respect to the Sun
205-208 F4.2 --- e_[FeI/H] FeI abundance uncertainty computed as the
dispersion among individual spectra
210-213 F4.2 --- e_[FeI/H]m Median of the FeI abundance uncertainties
quoted for the individual spectra
215-219 F5.2 --- [FeII/H] FeII abundance with respect to the Sun
221-224 F4.2 --- e_[FeII/H] FeII abundance uncertainty computed as the
dispersion among individual spectra
226-229 F4.2 --- e_[FeII/H]m Median of the FeII abundance uncertainties
quoted for the individual spectra
231-235 F5.2 --- [CoI/H] CoI abundance with respect to the Sun
237-240 F4.2 --- e_[CoI/H] CoI abundance uncertainty computed as the
dispersion among individual spectra
242-245 F4.2 --- e_[CoI/H]m Median of the CoI abundance uncertainties
quoted for the individual spectra
247-251 F5.2 --- [NiI/H] NiI abundance with respect to the Sun
253-256 F4.2 --- e_[NiI/H] NiI abundance uncertainty computed as the
dispersion among individual spectra
258-261 F4.2 --- e_[NiI/H]m Median of the NiI abundance uncertainties
quoted for the individual spectra
263-267 F5.2 --- [CuI/H] CuI abundance with respect to the Sun
269-272 F4.2 --- e_[CuI/H] CuI abundance uncertainty computed as the
dispersion among individual spectra
274-277 F4.2 --- e_[CuI/H]m Median of the CuI abundance uncertainties
quoted for the individual spectra
279-283 F5.2 --- [YII/H] YII abundance with respect to the Sun
285-288 F4.2 --- e_[YII/H] YII abundance uncertainty computed as the
dispersion among individual spectra
290-293 F4.2 --- e_[YII/H]m Median of the YII abundance uncertainties
quoted for the individual spectra
295-299 F5.2 --- [BaII/H] BaII abundance with respect to the Sun
301-304 F4.2 --- e_[BaII/H] BaII abundance uncertainty computed as the
dispersion among individual spectra
306-309 F4.2 --- e_[BaII/H]m Median of the BaII abundance uncertainties
quoted for the individual spectra
311-315 F5.2 --- [LaII/H] ? LaII abundance with respect to the Sun
317-320 F4.2 --- e_[LaII/H] ? LaII abundance uncertainty computed as the
dispersion among individual spectra
322-324 F3.1 --- e_[LaII/H]m ? Median of the LaII abundance uncertainties
quoted for the individual spectra
326-330 F5.2 --- [CeII/H] ? CeII abundance with respect to the Sun
332-335 F4.2 --- e_[CeII/H] ? CeII abundance uncertainty computed as the
dispersion among individual spectra
337-339 F3.1 --- e_[CeII/H]m ? Median of the CeII abundance uncertainties
quoted for the individual spectra
341-345 F5.2 --- [NdII/H] ? NdII abundance with respect to the Sun
347-350 F4.2 --- e_[NdII/H] ? NdII abundance uncertainty computed as the
dispersion among individual spectra
352-355 F4.2 --- e_[NdII/H]m ? Median of the NdII abundance uncertainties
quoted for the individual spectra
357-361 F5.2 --- [EuII/H] EuII abundance with respect to the Sun
363-366 F4.2 --- e_[EuII/H] EuII abundance uncertainty computed as the
dispersion among individual spectra
368-370 F3.1 --- e_[EuII/H]m Median of the EuII abundance uncertainties
quoted for the individual spectra
372-376 F5.2 --- [Fe/H]ref Reference value of the [Fe/H] abundance (1)
378-381 F4.2 --- e_[Fe/H]ref Uncertainty of the reference [Fe/H] abundance
383-387 F5.2 --- [Ca/H]ref Reference value of the [Ca/H] abundance (1)
389-392 F4.2 --- e_[Ca/H]ref Uncertainty of the reference [Ca/H] abundance
394-398 F5.2 --- [Co/H]ref Reference value of the [Co/H] abundance (1)
400-403 F4.2 --- e_[Co/H]ref Uncertainty of the reference [Co/H] abundance
405-409 F5.2 --- [Cr/H]ref Reference value of the [Cr/H] abundance (1)
411-414 F4.2 --- e_[Cr/H]ref Uncertainty of the reference [Cr/H] abundance
416-420 F5.2 --- [Mg/H]ref Reference value of the [Mg/H] abundance (1)
422-425 F4.2 --- e_[Mg/H]ref Uncertainty of the reference [Mg/H] abundance
427-431 F5.2 --- [Mn/H]ref Reference value of the [Mn/H] abundance (1)
433-436 F4.2 --- e_[Mn/H]ref Uncertainty of the reference [Mn/H] abundance
438-442 F5.2 --- [Ni/H]ref Reference value of the [Ni/H] abundance (1)
444-447 F4.2 --- e_[Ni/H]ref Uncertainty of the reference [Ni/H] abundance
449-453 F5.2 --- [Sc/H]ref Reference value of the [Sc/H] abundance (1)
455-458 F4.2 --- e_[Sc/H]ref Uncertainty of the reference [Sc/H] abundance
460-464 F5.2 --- [Si/H]ref Reference value of the [Si/H] abundance (1)
466-469 F4.2 --- e_[Si/H]ref Uncertainty of the reference [Si/H] abundance
471-475 F5.2 --- [Ti/H]ref Reference value of the [Ti/H] abundance (1)
477-480 F4.2 --- e_[Ti/H]ref Uncertainty of the reference [Ti/H] abundance
482-486 F5.2 --- [V/H]ref Reference value of the [V/H] abundance (1)
488-491 F4.2 --- e_[V/H]ref Uncertainty of the reference [V/H] abundance
493-502 A10 --- Groupref Reference group (2)
--------------------------------------------------------------------------------
Note (1): All reference values were taken from Jofre et al.
(2014, Cat. J/A+A/564/A133).
Note (2): Reference group as G dwarfs, K dwarfs or FGK giants.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- --- [Gaia DR2]
10- 28 I19 --- GaiaDR2 ID of the star (Gaia DR2, source_id)
30- 44 F15.10 deg RAdeg Right ascension (ICRS) at Ep=2000.0
46- 60 F15.11 deg DEdeg Declination (ICRS) at Ep=2000.0
62- 73 A12 --- Cluster Cluster name
75 I1 --- Nspec [1/5] Number of spectra analyzed
79- 94 F16.11 pc X X coordinate in the cartesian
Galactic frame
96- 112 F17.13 pc Y Y coordinate in the cartesian
Galactic frame
114- 128 F15.11 pc Z Z coordinate in the cartesian
Galactic frame
130- 144 F15.11 km/s U x projection of the total velocity
146- 161 F16.12 km/s V y projection of the total velocity
163- 179 F17.13 km/s W z projection of the total velocity
181- 195 F15.11 km/s RV Radial velocity (vel_atomic)
197- 211 F15.12 km/s e_RV Radial velocity uncertainty
(velatomicerr)
213- 225 F13.8 K TeffS Effective temperature (synth_teff)
227- 239 F13.11 [cm2/s] loggS Surface gravity (synth_logg)
241- 256 F16.13 --- [M/H]S Overall metallicity (synth_MH)
258- 270 F13.11 km/s vmicS Microturbulent velocity (synth_vmic)
272- 285 F14.11 K e_TeffS Effective temperature uncertainty
(synthtefferr)
287- 301 F15.13 [cm2/s] e_loggS Surface gravity uncertainty
(synthloggerr)
303- 318 F16.14 --- e_[M/H]S Overall metallicity uncertainty
(synthMHerr)
320- 334 F15.13 km/s e_vmicS Microturbulent velocity uncertainty
(synthvmicerr)
336- 352 F17.14 --- [AlI/H] Absolute abundance [Al1/H] computed
with respect to the Sun
354- 369 F16.14 --- e_[AlI/H] Uncertainty in the [AlI/H]
absolute abundance
371- 390 F20.17 --- [BaII/H] ? Absolute abundance [BaII/H] computed
with respect to the Sun
392- 411 F20.18 --- e_[BaII/H] ? Uncertainty in the [BaII/H] (25)
absolute abundance
413- 433 F21.18 --- [CaI/H] ? Absolute abundance [CaI/H] computed
with respect to the Sun
435- 454 F20.18 --- e_[CaI/H] ? Uncertainty in the [CaI/H]
absolute abundance
456- 475 F20.17 --- [CeII/H] ? Absolute abundance [CeII/H] computed
with respect to the Sun
477- 495 F19.17 --- e_[CeII/H] ? Uncertainty in the [CeII/H]
absolute abundance
497- 516 F20.17 --- [CoI/H] ? Absolute abundance [CoI/H] computed
with respect to the Sun
518- 537 F20.18 --- e_[CoI/H] ? Uncertainty in the [CoI/H]
absolute abundance
539- 559 F21.18 --- [CrI/H] ? Absolute abundance [CrI/H] computed
with respect to the Sun
561- 580 F20.18 --- e_[CrI/H] ? Uncertainty in the [CrI/H]
absolute abundance
582- 602 E21.18 --- [CuI/H] ? Absolute abundance [CuI/H] computed
with respect to the Sun
604- 624 F21.18 --- e_[CuI/H] ? Uncertainty in the [CuI/H]
absolute abundance
626- 646 F21.18 --- [EuII/H] ? Absolute abundance [EuII/H] computed
with respect to the Sun
648- 666 F19.17 --- e_[EuII/H] ? Uncertainty in the [EuII/H]
absolute abundance
668- 688 F21.18 --- [FeI/H] ? Absolute abundance [FeI/H] computed
with respect to the Sun
690- 709 F20.18 --- e_[FeI/H] ? Uncertainty in the [FeI/H]
absolute abundance
711- 731 E21.18 --- [FeII/H] ? Absolute abundance [FeII/H] computed
with respect to the Sun
733- 752 F20.18 --- e_[FeII/H] ? Uncertainty in the [FeII/H]
absolute abundance
754- 769 F16.13 --- [MgI/H] Absolute abundance [MgI/H] computed
with respect to the Sun
771- 786 F16.14 --- e_[MgI/H] Uncertainty in the [MgI/H]
absolute abundance
788- 808 F21.18 --- [MnI/H] ? Absolute abundance [MnI/H] computed
with respect to the Sun
810- 829 F20.18 --- e_[MnI/H] ? Uncertainty in the [MnI/H]
absolute abundance
831- 850 F20.17 --- [NaI/H] ? Absolute abundance [NaI/H] computed
with respect to the Sun
852- 871 F20.18 --- e_[NaI/H] ? Uncertainty in the [NaI/H]
absolute abundance
873- 893 F21.18 --- [NdII/H] ? Absolute abundance [NdII/H] computed
with respect to the Sun
895- 915 F21.17 --- e_[NdII/H] ? Uncertainty in the [NdII/H]
absolute abundance
917- 936 F20.17 --- [NiI/H] ? Absolute abundance [NiI/H] computed
with respect to the Sun
938- 957 F20.18 --- e_[NiI/H] ? Uncertainty in the [NiI/H]
absolute abundance
959- 979 F21.18 --- [ScII/H] ? Absolute abundance [ScII/H] computed
with respect to the Sun
981-1000 F20.18 --- e_[ScII/H] ? Uncertainty in the [ScII/H]
absolute abundance
1002-1022 F21.18 --- [SiI/H] ? Absolute abundance [SiI/H] computed
with respect to the Sun
1024-1043 F20.18 --- e_[SiI/H] ? Uncertainty in the [SiI/H]
absolute abundance
1045-1065 F21.18 --- [TiI/H] ? Absolute abundance [TiI/H] computed
with respect to the Sun
1067-1086 F20.18 --- e_[TiI/H] ? Uncertainty in the [TiI/H]
absolute abundance
1088-1107 F20.17 --- [TiII/H] ? Absolute abundance [TiII/H] computed
with respect to the Sun
1109-1128 F20.18 --- e_[TiII/H] ? Uncertainty in the [TiII/H]
absolute abundance
1130-1149 F20.17 --- [VI/H] ? Absolute abundance [VI/H] computed
with respect to the Sun
1151-1170 F20.18 --- e_[VI/H] ? Uncertainty in the [VI/H]
absolute abundance
1172-1192 F21.18 --- [YII/H] ? Absolute abundance [YII/H] computed
with respect to the Sun
1195-1214 F20.18 --- e_[YII/H] ? Uncertainty in the [YII/H]
absolute abundance
1216-1236 E21.18 --- difAlI ? Differential abundance of AlI computed
with respect to the reference star
1238-1257 E20.18 --- e_difAlI ? Uncertainty in the AlI differential
abundance
1259-1279 F21.18 --- difBaII ? Differential abundance of BaII computed
with respect to the reference star
1281-1300 F20.18 --- e_difBaII ? Uncertainty in the BaII differential
abundance
1302-1324 E23.20 --- difCaI ? Differential abundance of CaI computed
with respect to the reference star
1326-1345 F20.18 --- e_difCaI ? Uncertainty in the CaI differential
abundance
1347-1367 F21.18 --- difCeII ? Differential abundance of CeII computed
with respect to the reference star
1369-1387 F19.17 --- e_difCeII ? Uncertainty in the CeII differential
abundance
1389-1410 F22.19 --- difCoI ? Differential abundance of CoI computed
with respect to the reference star
1412-1431 F20.18 --- e_difCoI ? Uncertainty in the CoI differential
abundance
1433-1455 E23.20 --- difCrI ? Differential abundance of CrI computed
with respect to the reference star
1457-1476 F20.18 --- e_difCrI ? Uncertainty in the CrI differential
abundance
1478-1498 F21.18 --- difCuI ? Differential abundance of CuI computed
with respect to the reference star
1500-1519 F20.18 --- e_difCuI ? Uncertainty in the CuI differential
abundance
1521-1541 F21.18 --- difEuII ? Differential abundance of EuII computed
with respect to the reference star
1543-1561 F19.17 --- e_difEuII ? Uncertainty in the EuII differential
abundance
1563-1583 F21.18 --- difFeI ? Differential abundance of FeI computed
with respect to the reference star
1585-1604 F20.18 --- e_difFeI ? Uncertainty in the FeI differential
abundance
1606-1627 F22.19 --- difFeII ? Differential abundance of FeII computed
with respect to the reference star
1629-1648 F20.18 --- e_difFeII ? Uncertainty in the FeII differential
abundance
1650-1670 F21.18 --- difLaII ? Differential abundance of LaII computed
with respect to the reference star
1672-1691 F20.18 --- e_difLaII ? Uncertainty in the LaII differential
abundance
1693-1713 F21.18 --- difMgI ? Differential abundance of MgI computed
with respect to the reference star
1715-1734 F20.18 --- e_difMgI ? Uncertainty in the MgI differential
abundance
1736-1756 F21.18 --- difMnI ? Differential abundance of MnI computed
with respect to the reference star
1758-1777 F20.18 --- e_difMnI ? Uncertainty in the MnI differential
abundance
1779-1800 E22.19 --- difNaI ? Differential abundance of NaI computed
with respect to the reference star
1802-1821 F20.18 --- e_difNaI ? Uncertainty in the NaI differential
abundance
1823-1843 F21.18 --- difNdII ? Differential abundance of NdII computed
with respect to the reference star
1845-1864 F20.18 --- e_difNdII ? Uncertainty in the NdII differential
abundance
1866-1886 F21.18 --- difNiI ? Differential abundance of NiI computed
with respect to the reference star
1888-1907 F20.18 --- e_difNiI ? Uncertainty in the NiI differential
abundance
1909-1929 E21.18 --- difScII ? Differential abundance of ScII computed
with respect to the reference star
1931-1950 F20.18 --- e_difScII ? Uncertainty in the ScII differential
abundance
1952-1973 F22.19 --- difSiI ? Differential abundance of SiI computed
with respect to the reference star
1975-1994 F20.18 --- e_difSiI ? Uncertainty in the SiI differential
abundance
1996-2017 F22.19 --- difTiI ? Differential abundance of TiI computed
with respect to the reference star
2019-2038 F20.18 --- e_difTiI ? Uncertainty in the TiI differential
abundance
2040-2061 F22.19 --- difTiII ? Differential abundance of TiII computed
with respect to the reference star
2063-2082 F20.18 --- e_difTiII ? Uncertainty in the TiII differential
abundance
2084-2105 F22.19 --- difVI ? Differential abundance of VI computed
with respect to the reference star
2107-2126 F20.18 --- e_difVI ? Uncertainty in the VI differential
abundance
2128-2149 F22.19 --- difYII ? Differential abundance of YII computed
with respect to the reference star
2151-2170 F20.18 --- e_difYII ? Uncertainty in the YII differential
abundance
2172 A1 --- Flag [OETR] Flag (1)
--------------------------------------------------------------------------------
Note (1): Flag es follows:
O = star outlier in kinematic space (U,V,W)
E = star with large uncertainties in radial velocity
T = star belonging to the tidal tail of the respective cluster
R = star used as reference for the differential abundance
--------------------------------------------------------------------------------
Acknowledgements:
Laia Casamiquela, laia.casamiquela-floriach(at)u-bordeaux.fr
(End) Patricia Vannier [CDS] 22-Dec-2019