The Gaia-ESO Survey: the present-day radial metallicity distribution of the Galactic disc probed by pre-main-sequence clusters

DOI: 
10.1051/0004-6361/201630078
Publication date: 
01/05/2017
Main author: 
Spina, L.
IAA authors: 
Costado, M. T.
Authors: 
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.;Jofré, P.;Lewis, J.;Lind, K.;Monaco, L.;Morbidelli, L.;Prisinzano, L.;Sousa, S. G.;Worley, C. C.;Zaggia, S.
Journal: 
Astronomy and Astrophysics
Publication type: 
Article
Volume: 
601
Pages: 
A70
Abstract: 
Context. The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open star clusters allow us to derive both the radial metallicity distribution and its evolution over time. <BR /> Aims: 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 interstellar medium metallicity. <BR /> Methods: We used the products of the Gaia-ESO Survey analysis of 12 young regions (age 〈 100 Myr), covering Galactocentric distances from 6.67 to 8.70 kpc. For the first time, we derived the metal content of star forming regions farther than 500 pc 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 (i.e. Chamaeleon I and Gamma Velorum) we adopted the members identified in our previous works. <BR /> Results: 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 0.10-0.15 dex lower than the majority of the older clusters located at similar Galactocentric radii. <BR /> Conclusions: 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. Based on observations made with the ESO/VLT, at Paranal Observatory, under program 188.B-3002 (The Gaia-ESO Public Spectroscopic Survey).Full Table 1 is only available at the CDS via anonymous ftp to <A href='http://cdsarc.u-strasbg.fr'>http://cdsarc.u-strasbg.fr</A> (<A href='http://130.79.128.5'>http://130.79.128.5</A>) or via <A href='http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A70'>http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A70</A>
Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019042615&doi=10.1051%2f0004-6361%2f201630078&partnerID=40&md5=d7cd8ac947781e69acea8e68dc9f0105
ADS Bibcode: 
2017A&A...601A..70S
Keywords: 
stars: abundances;stars: pre-main sequence;Galaxy: abundances;Galaxy: disk;Galaxy: evolution;open clusters and associations: general;Astrophysics - Solar and Stellar Astrophysics;Astrophysics - Astrophysics of Galaxies