uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
The Gaia-ESO Survey: Insights into the inner-disc evolution from open clusters
INAF Osservatorio Astrofis Arcetri, I-50125 Florence, Italy..
INAF Osservatorio Astrofis Arcetri, I-50125 Florence, Italy..
INAF Osservatorio Astron Bologna, I-40127 Bologna, Italy.;Univ Bologna, Dipartimento Fis & Astron, I-40127 Bologna, Italy..
INAF Osservatorio Astron Bologna, I-40127 Bologna, Italy..
Show others and affiliations
2015 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 580, A85Article in journal (Refereed) Published
Abstract [en]

Context. The inner disc, which links the thin disc with the bulge, has been somewhat neglected in the past because of the intrinsic difficulties in its study, among which crowding and high extinction. Open clusters located in the inner disc are among the best tracers of its chemistry at different ages and distances. Aims. We analyse the chemical patterns of four open clusters located within 7 kpc of the Galactic centre and of field stars to infer the properties of the inner disc with the Gaia-ESO survey idr2/3 data release. Methods. We derive the parameters of the newly observed cluster, Berkeley 81, finding an age of about 1 Gyr and a Galactocentric distance of similar to 5.4 kpc. We construct the chemical patterns of clusters and we compare them with those of field stars in the solar neighbourhood and in the inner-disc samples. Results. Comparing the three populations we observe that inner-disc clusters and field stars are both, on average, enhanced in [O/Fe], [Mg/Fe], and [Si/Fe]. Using the idr2/3 results of M67, we estimate the non-local thermodynamic equilibrium (NLTE) effect on the abundances of Mg and Si in giant stars. After empirically correcting for NLTE effects, we note that NGC 6705 and Be 81 still have a high [alpha/Fe]. Conclusions. The location of the four open clusters and of the field population reveals that the evolution of the metallicity [Fe/H] and of [alpha/Fe] can be explained within the framework of a simple chemical evolution model: both [Fe/H] and [alpha/Fe] of Trumpler 20 and of NGC 4815 are in agreement with expectations from a simple chemical evolution model. On the other hand, NGC 6705, and to a lesser degree Berkeley 81, have higher [alpha/Fe] than expected for their ages, location in the disc, and metallicity. These differences might originate from local enrichment processes as explained in the inhomogeneous evolution framework.

Place, publisher, year, edition, pages
2015. Vol. 580, A85
Keyword [en]
Galaxy: abundances, open clusters and associations: general, open clusters and associations: individual: Trumpler 20, Galaxy: disk, open clusters and associations: individual: NGC 6705, globular clusters: individual: NGC 4815
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:uu:diva-263461DOI: 10.1051/0004-6361/201526305ISI: 000360020200085OAI: oai:DiVA.org:uu-263461DiVA: diva2:858088
European Science Foundation (ESF), 3855, 4127, 4415EU, FP7, Seventh Framework Programme, 264895Knut and Alice Wallenberg FoundationSwedish National Space Board
Available from: 2015-10-01 Created: 2015-09-30 Last updated: 2015-10-01Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Korn, Andreas
By organisation
Theoretical Astrophysics
In the same journal
Astronomy and Astrophysics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 506 hits
ReferencesLink to record
Permanent link

Direct link