Abundance ties: Nephele and the globular cluster population accreted with $\omega$ Cen. Based on APOGEE DR17 and Gaia EDR3

Abstract

The peculiar Galactic globular cluster $\omega$ Centauri (NGC 5139) has drawn attention for its unique features - such as a high stellar mass and a broad distribution of chemical elements - that have led to the hypothesis that it might be the nuclear remnant of an ancient dwarf galaxy accreted by the Milky Way (MW), potentially bringing along its own globular cluster (GC) system. In this work, we adopt an innovative approach by examining the individual chemical abundances of Galactic GCs. Applying Gaussian Mixture Models to globular cluster stars, whose membership is based on Gaia EDR3, and whose chemical abundances are provided by APOGEE DR17, we depart from traditional kinematic-based procedures and search for GCs that are chemically compatible with $\omega$ Cen in a 8-dimensional space defined by [Fe/H], [Mg/Fe], [Si/Fe], [Ca/Fe], [C/Fe], [Al/Fe], [K/Fe], and [Mn/Fe]. Our analysis leads to the identification of six GCs - NGC 6752, NGC 6656, NGC 6809, NGC 6273, NGC 6205, and NGC 6254 - that exhibit strong chemical similarities with $\omega$ Cen, and which have metallicities that coincide with those of the two main peaks of $\omega$ Cen's metallicity distribution. The chemical patterns of these clusters lead to the exclusion that they formed in progenitor galaxies with chemical enrichment histories similar to those of the Large and Small Magellanic Clouds, Sagittarius, and Fornax. Once placed in kinematic spaces such as the energy - angular momentum plane, these GCs result scattered across an extended region, which is predicted by N-body simulations if their common progenitor was sufficiently massive compared to the MW. Our novel approach suggests a common origin for NGC 6752, NGC 6656, NGC 6809, NGC 6273, NGC 6205, NGC 6254 and $\omega$ Cen, indicating that Nephele, as we propose to call the progenitor in which these GCs formed, played a substantial role in the Galaxy's history.

Accepted for publication on A&A

References in corpus (35)

• galpy: A Python Library for Galactic Dynamics
• The mass distribution and gravitational potential of the Milky Way
• Evidence for Two Early Accretion Events That Built the Milky Way Stellar Halo
• Gaia EDR3 view on Galactic globular clusters
• Kraken reveals itself -- the merger history of the Milky Way reconstructed with the E-MOSAICS simulations
• A stellar census in globular clusters with MUSE: The contribution of rotation to cluster dynamics studied with 200 000 stars
• Reverse engineering the Milky Way
• APOGEE Chemical Abundance Patterns of the Massive Milky Way Satellites
• The chemical characterisation of halo substructure in the Milky Way based on APOGEE
• Contribution of stripped nuclear clusters to globular cluster and ultra-compact dwarf galaxy populations
• The metallicity spread and the age-metallicity relation of Omega Centauri
• The Accreted Nuclear Clusters of the Milky Way
• Henize 2-10: the ongoing formation of a nuclear star cluster around a massive black hole
• GASTRO library I: the simulated chemodynamical properties of several GSE-like stellar halos
• On the rotation of nuclear star clusters formed by cluster-inspirals
• The Rotation of Sub-Populations in omega Centauri
• A deep view into the nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. I. Data and stellar population characterization
• A massive mess: When a large dwarf and a Milky Way-like galaxy merge
• Effects of Intermediate Mass Black Holes on Nuclear Star Clusters
• A Chemical Composition Survey of the Iron-Complex Globular Cluster NGC 6273 (M 19)
• The distribution of globular clusters in kinematic spaces does not trace the accretion history of the host galaxy
• Clearing the hurdle: The mass of globular cluster systems as a function of host galaxy mass
• A deep view into the nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. II. Kinematic characterization of the stellar populations
• Homogeneous Analysis of Globular Clusters from the APOGEE Survey with the BACCHUS Code $-$ III. $\omega$ Cen
• The complex stellar system M 22: confirming abundance variations with high precision differential measurements
• oMEGACat I: MUSE spectroscopy of 300,000 stars within the half-light radius of $\omega$ Centauri
• The stellar halo in Local Group Hestia simulations I. The in-situ component and the effect of mergers
• Probing the formation history of the nuclear star cluster at the Galactic Centre with millisecond pulsars
• The stellar halo in Local Group Hestia simulations II. The accreted component
• On the role of Type Ia supernovae in the second generation star formation in globular clusters
• MgAl burning chain in Omega Centauri
• High-precision abundances of first population stars in NGC 2808: confirmation of a metallicity spread
• The not so simple stellar system Omega Cen. II. Evidence in support of a merging scenario
• A Deep View into the Nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. III. Discrete multi-component population-dynamical models based on the Jeans equations
• The proper motion of sub-populations in Omega Centauri

Cited by in corpus (7)

• oMEGACat. VI. Analysis of the overall kinematics of Omega Centauri in 3D: velocity dispersion, kinematic distance, anisotropy, and energy equipartition
• Studying stellar populations in Omega Centauri with phylogenetics
• Chemical tagging with APOGEE, MUSE, and HST: constraints on the formation of $\omega$ Centauri
• Build-up and survival of the disc: From numerical models of galaxy formation to the Milky Way
• The Nephele ecosystem: stars, globular clusters, and stellar streams associated with the progenitor galaxy of $\omega$ Centauri
• Survey of Surveys. II. Stellar parameters for 23 millions of stars
• Disruption of a Giant: Spectroscopic Identification of Members in the Periphery and Tidal Tails of $\omega$ Centauri