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The Gaia-ESO Survey: Abundance ratios in the inner-disk open clusters Trumpler 20, NGC 4815, NGC 6705

Magrini, L.; Randich, S.; Romano, D.; Friel, E.; Bragaglia, A.; Smiljanic, R.; Jacobson, H.; Vallenari, A.; Tosi, M. and Spina, L., et al. (2014) In Astronomy & Astrophysics 563.
Abstract
Context. Open clusters are key tools to study the spatial distribution of abundances in the disk and their evolution with time. Aims. Using the first release of stellar parameters and abundances of the Gaia-ESO Survey, we analyse the chemical properties of stars in three old/intermediate-age open clusters, namely NGC 6705, NGC 4815, and Trumpler 20, which are all located in the inner part of the Galactic disk at Galactocentric radius R-GC similar to 7 kpc. We aim to prove their homogeneity and to compare them with the field population. Methods. We study the abundance ratios of elements belonging to two different nucleosynthetic channels: alpha-elements and iron-peak elements. For each element, we analyse the internal chemical homogeneity... (More)
Context. Open clusters are key tools to study the spatial distribution of abundances in the disk and their evolution with time. Aims. Using the first release of stellar parameters and abundances of the Gaia-ESO Survey, we analyse the chemical properties of stars in three old/intermediate-age open clusters, namely NGC 6705, NGC 4815, and Trumpler 20, which are all located in the inner part of the Galactic disk at Galactocentric radius R-GC similar to 7 kpc. We aim to prove their homogeneity and to compare them with the field population. Methods. We study the abundance ratios of elements belonging to two different nucleosynthetic channels: alpha-elements and iron-peak elements. For each element, we analyse the internal chemical homogeneity of cluster members, and we compare the cumulative distributions of cluster abundance ratios with those of solar neighbourhood turn-off stars and of inner-disk/bulge giants. We compare the abundance ratios of field and cluster stars with two chemical evolution models that predict different alpha-enhancement dependences on the Galactocentric distance due to different assumptions on the infall and star-formation rates. Results. The main results can be summarised as follows: i) cluster members are chemically homogeneous within 3 sigma in all analysed elements; ii) the three clusters have comparable [El/Fe] patterns within similar to 1 sigma, but they differ in their global metal content [El/H] with NGC 4815 having the lowest metallicity; their [El/Fe] ratios show differences and analogies with those of the field population, in both the solar neighbourhood and the bulge/inner disk; iii) comparing the abundance ratios with the results of two chemical evolution models and with field star abundance distributions, we find that the abundance ratios of Mg, Ni, and Ca in NGC 6705 might require an inner birthplace, implying a subsequent variation in its R-GC during its lifetime, which is consistent with previous orbit determination. Conclusions. Using the results of the first internal data release, we show the potential of the Gaia-ESO Survey through a homogeneous and detailed analysis of the cluster versus field populations to reveal the chemical structure of our Galaxy using a completely uniform analysis of different populations. We verify that the Gaia-ESO Survey data are able to identify the unique chemical properties of each cluster by pinpointing the composition of the interstellar medium at the epoch and place of formation. The full dataset of the Gaia-ESO Survey is a superlative tool to constrain the chemical evolution of our Galaxy by disentangling different formation and evolution scenarios. (Less)
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Galaxy: abundances, open clusters and associations: general, open, clusters and associations: individual: Trumpler 20, open clusters and, associations: individual: NGC 4815, globular clusters: individual: NGC, 6705, Galaxy: disk
in
Astronomy & Astrophysics
volume
563
publisher
EDP Sciences
external identifiers
  • wos:000333798000044
  • scopus:84897586101
ISSN
0004-6361
DOI
10.1051/0004-6361/201322977
language
English
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yes
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1d03605d-6928-4a78-a213-271b733114d1 (old id 4439847)
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2014-05-20 10:35:57
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2017-06-18 04:14:07
@article{1d03605d-6928-4a78-a213-271b733114d1,
  abstract     = {Context. Open clusters are key tools to study the spatial distribution of abundances in the disk and their evolution with time. Aims. Using the first release of stellar parameters and abundances of the Gaia-ESO Survey, we analyse the chemical properties of stars in three old/intermediate-age open clusters, namely NGC 6705, NGC 4815, and Trumpler 20, which are all located in the inner part of the Galactic disk at Galactocentric radius R-GC similar to 7 kpc. We aim to prove their homogeneity and to compare them with the field population. Methods. We study the abundance ratios of elements belonging to two different nucleosynthetic channels: alpha-elements and iron-peak elements. For each element, we analyse the internal chemical homogeneity of cluster members, and we compare the cumulative distributions of cluster abundance ratios with those of solar neighbourhood turn-off stars and of inner-disk/bulge giants. We compare the abundance ratios of field and cluster stars with two chemical evolution models that predict different alpha-enhancement dependences on the Galactocentric distance due to different assumptions on the infall and star-formation rates. Results. The main results can be summarised as follows: i) cluster members are chemically homogeneous within 3 sigma in all analysed elements; ii) the three clusters have comparable [El/Fe] patterns within similar to 1 sigma, but they differ in their global metal content [El/H] with NGC 4815 having the lowest metallicity; their [El/Fe] ratios show differences and analogies with those of the field population, in both the solar neighbourhood and the bulge/inner disk; iii) comparing the abundance ratios with the results of two chemical evolution models and with field star abundance distributions, we find that the abundance ratios of Mg, Ni, and Ca in NGC 6705 might require an inner birthplace, implying a subsequent variation in its R-GC during its lifetime, which is consistent with previous orbit determination. Conclusions. Using the results of the first internal data release, we show the potential of the Gaia-ESO Survey through a homogeneous and detailed analysis of the cluster versus field populations to reveal the chemical structure of our Galaxy using a completely uniform analysis of different populations. We verify that the Gaia-ESO Survey data are able to identify the unique chemical properties of each cluster by pinpointing the composition of the interstellar medium at the epoch and place of formation. The full dataset of the Gaia-ESO Survey is a superlative tool to constrain the chemical evolution of our Galaxy by disentangling different formation and evolution scenarios.},
  articleno    = {A44},
  author       = {Magrini, L. and Randich, S. and Romano, D. and Friel, E. and Bragaglia, A. and Smiljanic, R. and Jacobson, H. and Vallenari, A. and Tosi, M. and Spina, L. and Donati, P. and Maiorca, E. and Cantat-Gaudin, T. and Sordo, R. and Bergemann, M. and Damiani, F. and Tautvaisiene, G. and Blanco-Cuaresma, S. and Jimenez-Esteban, F. and Geisler, D. and Mowlavi, N. and Munoz, C. and San Roman, I. and Soubiran, C. and Villanova, S. and Zaggia, S. and Gilmore, G. and Asplund, M. and Feltzing, Sofia and Jeffries, R. and Bensby, Thomas and Koposov, S. and Korn, A. J. and Flaccomio, E. and Pancino, E. and Recio-Blanco, A. and Sacco, G. and Costado, M. T. and Franciosini, E. and Jofre, P. and de Laverny, P. and Hill, V. and Heiter, U. and Hourihane, A. and Jackson, R. and Lardo, C. and Morbidelli, L. and Lewis, J. and Lind, K. and Masseron, T. and Prisinzano, L. and Worley, C.},
  issn         = {0004-6361},
  keyword      = {Galaxy: abundances,open clusters and associations: general,open,clusters and associations: individual: Trumpler 20,open clusters and,associations: individual: NGC 4815,globular clusters: individual: NGC,6705,Galaxy: disk},
  language     = {eng},
  publisher    = {EDP Sciences},
  series       = {Astronomy & Astrophysics},
  title        = {The Gaia-ESO Survey: Abundance ratios in the inner-disk open clusters Trumpler 20, NGC 4815, NGC 6705},
  url          = {http://dx.doi.org/10.1051/0004-6361/201322977},
  volume       = {563},
  year         = {2014},
}