Bibcode
Blanco-Cuaresma, S.; Soubiran, C.; Heiter, U.; Asplund, M.; Carraro, G.; Costado, M. T.; Feltzing, S.; González-Hernández, J. I.; Jiménez-Esteban, F.; Korn, A. J.; Marino, A. F.; Montes, D.; San Roman, I.; Tabernero, H. M.; Tautvaišienė, G.
Bibliographical reference
Astronomy and Astrophysics, Volume 577, id.A47, 15 pp.
Advertised on:
5
2015
Journal
Citations
74
Refereed citations
65
Description
Context. Stars are born together from giant molecular clouds and, if we
assume that the priors were chemically homogeneous and well-mixed, we
expect them to share the same chemical composition. Most of the stellar
aggregates are disrupted while orbiting the Galaxy and most of the
dynamic information is lost, thus the only possibility of reconstructing
the stellar formation history is to analyze the chemical abundances that
we observe today. Aims: The chemical tagging technique aims to
recover disrupted stellar clusters based merely on their chemical
composition. We evaluate the viability of this technique to recover
co-natal stars that are no longer gravitationally bound. Methods:
Open clusters are co-natal aggregates that have managed to survive
together. We compiled stellar spectra from 31 old and intermediate-age
open clusters, homogeneously derived atmospheric parameters, and 17
abundance species, and applied machine learning algorithms to group the
stars based on their chemical composition. This approach allows us to
evaluate the viability and efficiency of the chemical tagging technique.
Results: We found that stars at different evolutionary stages
have distinct chemical patterns that may be due to NLTE effects, atomic
diffusion, mixing, and biases. When separating stars into dwarfs and
giants, we observed that a few open clusters show distinct chemical
signatures while the majority show a high degree of overlap. This limits
the recovery of co-natal aggregates by applying the chemical tagging
technique. Nevertheless, there is room for improvement if more elements
are included and models are improved.
Based on observations obtained at the Telescope Bernard Lyot (USR5026)
operated by the Observatoire Midi-Pyrénées,
Université de Toulouse (Paul Sabatier), Centre National de la
Recherche Scientifique of France, and on public data obtained from the
ESO Science Archive Facility under requests number 81252 and 81618.