Testing the chemical homogeneity of chemically tagged dissolved birth clusters

Abstract

Chemically tagging stars back to common formation sites in the Milky Way and establishing a high level of chemical homogeneity in these chemically tagged birth clusters is crucial for understanding the chemical and dynamical history of the Galactic disc. We constrain the intrinsic abundance scatter in 17 newly chemically tagged dissolved birth clusters found in the APOGEE survey by modelling APOGEE spectra as a one-dimensional function of initial stellar mass, performing forward modelling of the observed stellar spectra, then comparing the data and simulations using Approximate Bayesian Computation. We exemplify this method with the well-known open clusters M67, NGC 6819, and NGC 6791. We study 15 elements measured by APOGEE and find that, in general, we are able to obtain very strong constraints on the intrinsic abundance scatter of most elements in the chemically tagged birth clusters, with upper limits of $\lesssim 0.02$ dex for C, $\lesssim 0.03$ dex for O, Mn, and Fe, $\lesssim 0.04$ dex for Si and Ni, and $\lesssim 0.05$ dex for N, Mg, and Ca. While we find some evidence for a small amount of chemical inhomogeneity in the remaining elements (i.e. Na, Al, S, K, Ti, and V), we are still able to obtain similar or stronger limits compared to those found for open clusters, consistent with previous findings. By strongly constraining their level of chemical homogeneity, we can strengthen the statement that these groups of stars represent birth clusters, with promising implications for future chemical tagging studies.

MNRAS, in press

References in corpus (12)

• The 2.5 m Telescope of the Sloan Digital Sky Survey
• The APOGEE red-clump catalog: Precise distances, velocities, and high-resolution elemental abundances over a large area of the Milky Way's disk
• Data analysis recipes: Fitting a model to data
• Exploring Anticorrelations and Light Element Variations in Northern Globular Clusters Observed by the APOGEE Survey
• Chemical Homogeneity in Collinder 261 and Implications for Chemical Tagging
• Chemical Abundances of Main-Sequence, Turnoff, Subgiant and red giant Stars from APOGEE spectra II: Atomic Diffusion in M67 Stars
• Early turbulent mixing as the origin of chemical homogeneity in open star clusters
• Testing the chemical tagging technique with open clusters
• Chemical (in)homogeneity and atomic diffusion in the open cluster M67
• Prospects for chemically tagging stars in the Galaxy
• Differential abundances of open clusters and their tidal tails: chemical tagging and chemical homogeneity
• Detailed chemical compositions of planet hosting stars: I. Exploration of possible planet signatures

Cited by in corpus (6)

• The homogeneity of the star forming environment of the Milky Way disk over time
• A metallicity study of F, G, K and M dwarfs in the Coma Berenices open cluster from the APOGEE survey
• Accurate X-ray Timing in the Presence of Systematic Biases With Simulation-Based Inference
• A GALAH View of the Chemical Homogeneity and Ages of Stellar Strings Identified in Gaia
• The dawn is quiet here: Rise in [$\alpha$/Fe] is a signature of massive gas accretion that fueled proto-Milky Way
• Identifying substructure associations in the Milky Way halo using chemo-kinematic tagging