Galactic Archaeology and Minimum Spanning Trees

TL;DR

This paper explores reconstructing stellar birth clouds using chemical tagging and minimum spanning trees, highlighting challenges due to uncertainties in chemical abundance measurements.

Contribution

It introduces a parametric MST approach to reconstruct dissolved stellar associations and assesses its limitations with realistic chemical abundance uncertainties.

Findings

Significant degeneracies occur at 0.1 dex abundance uncertainties.

MST approach alone is insufficient for accurate reconstruction.

More advanced methods are needed to improve reconstruction accuracy.

Abstract

Chemical tagging of stellar debris from disrupted open clusters and associations underpins the science cases for next-generation multi-object spectroscopic surveys. As part of the Galactic Archaeology project TraCD (Tracking Cluster Debris), a preliminary attempt at reconstructing the birth clouds of now phase-mixed thin disk debris is undertaken using a parametric minimum spanning tree (MST) approach. Empirically-motivated chemical abundance pattern uncertainties (for a 10-dimensional chemistry-space) are applied to NBODY6-realised stellar associations dissolved into a background sea of field stars, all evolving in a Milky Way potential. We demonstrate that significant population reconstruction degeneracies appear when the abundance uncertainties approach 0.1 dex and the parameterised MST approach is employed; more sophisticated methodologies will be required to ameliorate these degeneracies.