J/MNRAS/496/4701 Gaia-ESO Survey: members of 32 open clusters (Jackson+, 2020)
The Gaia-ESO Survey: membership probabilities for stars in 32 open clusters
from 3D kinematics.
Jackson R.J., Jeffries R.D., Wright N.J., Randich S., Sacco G., Pancino E.,
Cantat-Gaudin T., Gilmore G., Vallenari A., Bensby T., Bayo A.,
Costado M.T., Franciosini E., Gonneau A., Hourihane A., Lewis J.,
Monaco L., Morbidelli L., Worley C.
<Mon. Not. R. Astron. Soc., 496, 4701-4716 (2020)>
=2020MNRAS.496.4701J 2020MNRAS.496.4701J (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Spectra, optical ; Milky Way ; Positional data ;
Effective temperatures ; Radial velocities ; Space velocities ;
Parallaxes, trigonometric
Keywords: stars: evolution - stars: pre-main-sequence -
open clusters and associations: general
Abstract:
The Gaia-ESO Survey (GES) observed many open clusters as part of its
programme to spectroscopically characterize the various Milky Way
populations. GES spectroscopy and Gaia astrometry from its second data
release are used here to assign membership probabilities to targets
towards 32 open clusters with ages from 1 to 3800Myr, based on maximum
likelihood modelling of the 3D kinematics of the cluster and field
populations. From a parent catalogue of 14398 individual targets, 5032
stars with uniformly determined 3D velocities, Teff, log g, and
chemistry are assigned cluster membership with probability >0.9, and
with an average probability of 0.991. The robustness of the membership
probabilities is demonstrated using independent membership criteria
(lithium and parallax) in two of the youngest clusters. The addition
of radial velocities improves membership discrimination over proper
motion selection alone, especially in more distant clusters. The
kinematically selected nature of the membership lists, independent of
photometry and chemistry, makes the catalogue a valuable resource for
testing stellar evolutionary models and investigating the time
evolution of various parameters.
Description:
GES Data for 32 open clusters was taken from the GESiDR5 analysis
iteration in the GES archive at the Wide Field Astronomy Unit of
Edinburgh University (http//ges/roe.ac.uk/). Table 1 shows a list of
cluster names together with initial values of age, distance modulus
and reddening reported in the literature. Also shown are the number of
targets in each cluster that were observed using the GIRAFFE 665nm
filter (HR15n) and/or the UVES 520 or 580nm filters. A summary of the
target selection strategy for the GES clusters can be found in Randich
et al. (2018A&A...612A..99R 2018A&A...612A..99R, Cat. J/A+A/612/A99) and summaries of the
spectroscopic data and analyses can be found in Sacco et al.
(2014A&A...565A.113S 2014A&A...565A.113S), Damiani et al. (2014A&A...566A..50D 2014A&A...566A..50D, Cat.
J/A+A/566/A50), Jeffries et al. (2014A&A...563A..94J 2014A&A...563A..94J, Cat.
J/A+A/563/A94), Smiljanic et al. (2014A&A...570A.122S 2014A&A...570A.122S), and Jackson et
al. (2015A&A...580A..75J 2015A&A...580A..75J, Cat. J/A+A/580/A75).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 103 32 Cluster data
table2.dat 116 26000 Gaia-ESO Survey data used to estimate the
probability of cluster membership for targets
observed in the 32 clusters of Table 1
table3.dat 117 26000 Gaia data for targets observed in the 32
clusters of Table 1 and other calculated
parameters
table4.dat 100 32 Results of the maximum likelihood analysis of
cluster membership
refs.dat 83 44 References for Table 1
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/612/A99 : Gaia-ESO Survey in 7 open star cluster fields (Randich+, 2018)
J/A+A/566/A50 : Classification of stellar spectra 644-681nm (Damiani+, 2014)
J/A+A/563/A94 : Kinematics of the Gamma Vel cluster (Jeffries+, 2014)
J/A+A/580/A75 : Velocity precision in the Gaia-ESO Survey (Jackson+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Cluster Cluster name
15- 17 I3 Myr b_Age []? Lower bound on Age
19- 22 I4 Myr Age ? Cluster age
24- 26 I3 Myr B_Age ? Upper bound on Age
28- 29 I2 --- r_Age Reference for Age
31- 35 F5.2 mag mulit Distance modulus from literature
37- 38 I2 --- r_mulit Reference for mulit
40- 42 F3.1 mag b_E(B-V)lit ? Lower bound on E(B-V)lit
44 A1 --- l_E(B-V)lit [~] Limit flag on E(B-V)lit
46- 49 F4.2 mag E(B-V)lit ? Reddening from literature
51- 53 F3.1 mag B_E(B-V)lit ? Upper bound on E(B-V)lit
55- 56 I2 --- r_E(B-V)lit ? Reference for E(B-V)lit
58- 61 I4 --- Nobs Number of observed targets
63- 66 I4 --- Ncomp Number of targets with a full set of the
required data
68- 71 I4 --- Nfit Number of fitted targets in the membership
analysis
73- 77 I5 --- Res Spectral resolving power measured from arc
lamp line widths
79- 83 F5.2 mag mumemb Mean distance modulus determined from
high-probability cluster members
85- 88 F4.2 mag s_mumemb Statistical uncertainty on mumemb
90- 93 F4.2 mag e_mumemb Systematic uncertainty on mumemb
corresponding to ±0.1mas in parallax
95- 98 F4.2 mag E(B-V)memb Mean reddening determined from
high-probability cluster members
100- 103 F4.2 mag e_E(B-V)memb Error on E(B-V)memb
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Target designation (HHMMSSss+DDMMSSs)
18- 20 I3 nm Filter Filter wavelength
22- 34 A13 --- Cluster Cluster name
36- 44 F9.5 deg RAdeg Right ascension (J2000)
46- 53 F8.4 deg DEdeg Declination (J2000)
55- 61 F7.2 --- S/N Signal to noise ratio
63- 67 I5 K Teff ?=-999 Effective temperature (1)
69- 76 F8.3 [cm/s2] logg ?=-999 Surface gravity (1)
78- 85 F8.3 --- gamma ?=-999 Gravity-sensitive spectroscopic index
(1)
87- 92 F6.3 mag Ksmag Ks-band magnitude
94- 101 F8.3 km/s RV ?=-999 Radial velocity
103- 109 F7.2 km/s e_RV ?=-999 Error on RV
111- 116 F6.2 [Lsun] logL ?=-99 Logarithm of the stellar luminosity
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Note (1): Wherever possible, values for effective temperature, surface gravity
and the gravity-sensitive spectroscopic index γ (Damiani et al.
2014A&A...566A..50D 2014A&A...566A..50D, Cat. J/A+A/566/A50) were taken from the
RecommendedAstroAnalysis data base. If no value is given in that
data base then the parameter is taken from the Astro_Analysis data
base. If the Astro_Analysis data base show multiple values from
different working groups then we show their median value.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Target designation (HHMMSSss+DDMMSSs)
18- 20 I3 nm Filter Filter wavelength
22- 34 A13 --- Cluster Cluster name
36- 42 F7.2 mas plx ?=-999 Parallax
44- 50 F7.2 mas e_plx ?=-999 Error on plx
52- 59 F8.2 km/s VRA ?=-999 Velocity in right ascension (1)
61- 67 F7.2 km/s e_VRA ?=-999 Error on VRA
69- 75 F7.2 km/s VDec ?=-999 Velocity in declination (1)
77- 83 F7.2 km/s e_VDec ?=-999 Error on VDec
85- 91 F7.2 km/s RV ?=-999 Radial velocity
93- 99 F7.2 km/s SRV ?=-999 Radial velocity precision (2)
101 I1 --- FlagG [0/1] Gaia flag (3)
103- 109 F7.4 --- p Probability that the target is a member of its
given cluster using the full data set (4)
111- 117 F7.4 --- pfilter Probability that the target is a member of its
given cluster using a data set filtered to
remove any targets with a Gaia flag =0 (4)
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Note (1): The tangential velocities are calculated as:
VRA=4.74dcpmRA and VDec=4.74dcpmDec, where pmRA and
pmDec are the proper motions in units of mas/yr, and dc (in pc)
is the cluster distance used for the analysis of cluster membership
Note (2): For targets observed with the GIRAFFE 665nm filter, an improved
empirical precision, SRV, is calculated from the target
signal-to-noise ratio (S/N) and projected equatorial velocity (vsini),
following the method described in Jackson et al. (2015A&A...580A..75J 2015A&A...580A..75J,
Cat. J/A+A/580/A75), and using empirical constants determined from
the analysis of GESiDR5 cluster data (see Appendix A)
Note (3): A Gaia flag of zero indicates targets with potentially unreliable
Gaia data <8 visibility periods or renormalized weighted error <1.4
(see Section 5.1 and Lindegren et al. 2018A&A...616A...2L 2018A&A...616A...2L, Cat. I/345)
Note (4): Targets with a membership probability of -1 were excluded from the
membership analysis
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Cluster Cluster name
15- 21 F7.2 km/s URA Cluster central velocity in right ascension
23- 26 F4.2 km/s e_URA Error on URA
28- 34 F7.2 km/s UDec Cluster central velocity in declination
36- 39 F4.2 km/s e_UDec Error on UDec
41- 46 F6.2 km/s URV Cluster central radial velocity
48- 51 F4.2 km/s e_URV Error on URV
53- 56 F4.2 km/s DRA Intrinsic dispersion of cluster in right
ascension
58- 61 F4.2 km/s e_DRA Error on DRA
63- 66 F4.2 km/s DDec Intrinsic dispersion of cluster in
declination
68- 71 F4.2 km/s e_DDec Error on DDec
73- 77 F5.2 km/s DRV Intrinsic radial velocity dispersion of
cluster
79- 82 F4.2 km/s e_DRV Error on DRV
84- 87 F4.2 --- frac Proportion of targets analysed that are
expected cluster members (Nfit from Table 1)
89- 92 F4.2 --- e_frac Error on frac
94- 96 I3 --- Memb0.9 Number of targets with membership
probability>0.9
98- 100 I3 --- Memb0.95 Number of targets with membership
probability>0.95
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref [1/44] Reference number
4- 22 A19 --- BibCode BibCode
24- 61 A38 --- Aut Author's name
63- 83 A21 --- Com Comments
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 20-Jul-2023