J/A+A/601/A70 GES: pre-main-sequence clusters [Fe/H] (Spina+, 2017)
The Gaia-ESO Survey: the present-day radial metallicity distribution of the
Galactic disc probed by pre-main-sequence clusters.
Spina L., Randich S., Magrini L., Jeffries R.D., Friel E.D., Sacco G.G.,
Pancino E., Bonito R., Bravi L., Franciosini E., Klutsch A., Montes D.,
Gilmore G., Vallenari A., Bensby T., Bragaglia A., Flaccomio E.,
Koposov S.E., Korn A.J., Lanzafame A.C., Smiljanic R., Bayo A., Carraro G.,
Casey A.R., Costado M.T., Damiani F., Donati P., Frasca A., Hourihane A.,
Jofre P., Lewis J., Lind K., Monaco L., Morbidelli L., Prisinzano L.,
Sousa S.G., Worley C.C., Zaggia S.
<Astron. Astrophys. 601, A70 (2017)>
=2017A&A...601A..70S 2017A&A...601A..70S (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Effective temperatures ; Abundances
Keywords: stars: abundances - stars: pre-main sequence - Galaxy: abundances -
Galaxy: disc - Galaxy: evolution -
open clusters and associations: general
Abstract:
The radial metallicity distribution in the Galactic thin disc
represents a crucial constraint for modelling disc formation and
evolution. Open clusters allow us to derive both the radial
metallicity distribution and its evolution over time. In this paper we
perform the first investigation of the present-day radial metallicity
distribution based on [Fe/H] determinations in late type members of
pre-main-sequence clusters. Because of their youth, these clusters are
therefore essential for tracing the current inter-stellar medium
metallicity. We used the products of the Gaia-ESO Survey analysis of
12 young regions (age<100Myr), covering Galactocentric distances from
6.67 to 8.70kpc. For the first time, we derived the metal content of
star forming regions farther than 500pc from the Sun. Median
metallicities were determined through samples of reliable cluster
members. For ten clusters the membership analysis is discussed in the
present paper, while for other two clusters (Chamaeleon I and Gamma
Velorum) we adopted the members identified in our previous works. All
the pre-main-sequence clusters considered in this paper have
close-to-solar or slightly sub-solar metallicities. The radial
metallicity distribution traced by these clusters is almost flat, with
the innermost star forming regions having [Fe/H] values that are
0.10-0.15dex lower than the majority of the older clusters located at
similar Galactocentric radii. This homogeneous study of the
present-day radial metallicity distribution in the Galactic thin disc
favours models that predict a flattening of the radial gradient over
time. On the other hand, the decrease of the average [Fe/H] at young
ages is not easily explained by the models. Our results reveal a
complex interplay of several processes (e.g. star formation activity,
initial mass function, supernova yields, gas flows) that controlled
the recent evolution of the Milky Way.
Description:
Stellar parameters, equivalent widths of the lithium line at
6707.8Å and gamma indexes of the cluster members. Values from the
Gaia-ESO Survey iDR4 catalogue.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 110 536 Stellar parameters, EWs of the lithium line at
6707.8Å and gamma indexes of cluster members
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/A+A/567/A55 : Metallicity of the γ Vel cluster (Spina+, 2014)
J/A+A/569/A17 : Gaia-ESO Survey: NGC6705 (Cantat-Gaudin+, 2014)
J/A+A/572/A33 : Abundances from Gaia-ESO Survey (Mikolaitis+, 2014)
J/A+A/573/A55 : Gaia-ESO Survey: Tr 20, NGC4815, NGC6705 (Tautvaisiene+, 2015)
J/A+A/575/A4 : Activity and accretion in γ Vel and Cha I (Frasca+, 2015)
J/A+A/598/A5 : Gaia-ESO Survey iDR4 calibrators (Pancino+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- CName Object name (HHMMSSss+DDMMSSs)
18- 19 I2 h RAh Right ascension (J2000.0)
21- 22 I2 min RAm Right ascension (J2000.0)
24- 28 F5.2 s RAs Right ascension (J2000.0)
30 A1 --- DE- Declination sign (J2000.0)
31- 32 I2 deg DEd Declination (J2000.0)
34- 35 I2 arcmin DEm Declination (J2000.0)
37- 40 F4.1 arcsec DEs Declination (J2000.0)
42- 49 A8 --- Cluster Cluster name (1)
51- 55 A5 --- Grating Instrument grating (HR15N or U580)
57- 60 I4 K Teff Effective temperature
62- 64 I3 K e_Teff Error on Teff
66- 69 F4.2 [cm/s2] logg ? Surface gravity
71- 74 F4.2 [cm/s2] e_logg ? Error on logg
76- 80 F5.2 [-] [Fe/H] Iron abundance
82- 85 F4.2 [-] e_[Fe/H] Error on [Fe/H]
87- 91 F5.1 0.1pm EW(Li) Equivalent width of the lithium line at
6707.8Å
93- 96 F4.1 0.1pm e_EW(Li) Error on EW(Li)
98-103 F6.4 --- gamma ? gamma index
105-110 F6.4 --- e_gamma ? Error on gamma
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Note (1): Studied clusters:
Carina, IC2391, IC2602, IC4665, NGC2264, NGC2451A, NGC2451B, NGC2547, NGC6530
and RhoOph
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Acknowledgements:
Lorenzo Spina, lspina(at)usp.br
(End) Patricia Vannier [CDS] 23-Feb-2017