Chemical tagging experiment with the Gaia-ESO open clusters

TL;DR

This study tests chemical tagging for open cluster membership using Gaia-ESO data, comparing chemical, radial velocity, and proper motion criteria, revealing some overlaps and discrepancies in cluster identification.

Contribution

It provides preliminary insights into the effectiveness of chemical tagging in open clusters and compares cluster abundances with field stars, highlighting potential overlaps.

Findings

Some cluster members identified by chemical tagging differ from other criteria.

Field stars with similar abundances to clusters were found.

Open clusters may not have unique chemical signatures.

Abstract

Stars observed in the field of an open cluster are ideal for a controlled test of chemical tagging. Using chemical tagging, one should identify the cluster members, i.e., those stars of similar chemical composition, if their composition is indeed different from that of all the non-member stars of the field. Moreover, the abundance-based membership can be checked against membership based on radial velocities and proper motions. Here, I report preliminary results of such an experiment using data from the Gaia-ESO Survey. Although the three membership criteria usually agree, a few interesting examples of discrepant membership classification have been found. In addition, the mean composition of each open cluster was compared to a sample of 1600 Gaia-ESO field stars. Some cases of field stars with abundances matching those of the open clusters were identified. This experiment suggests that open clusters do not necessarily have unique abundance patterns that set them apart from all other clusters.