The GALAH Survey: Chemically tagging the Fimbulthul stream to the globular cluster $\omega$ Centauri

Abstract

Using kinematics from Gaia and the large elemental abundance space of the second data release of the GALAH survey, we identify two new members of the Fimbulthul stellar stream, and chemically tag them to massive, multi-metallic globular cluster $\omega$ Centauri. Recent analysis of the second data release of Gaia had revealed the Fimbulthul stellar stream in the halo of the Milky Way. It had been proposed that the stream is associated with the $\omega$ Centauri, but this proposition relied exclusively upon the kinematics and metallicities of the stars to make the association. In this work, we find our two new members of the stream to be metal-poor stars that are enhanced in sodium and aluminium, typical of second population globular cluster stars, but not otherwise seen in field stars. Furthermore, the stars share the s-process abundance pattern seen in $\omega$ Centauri, which is rare in field stars. Apart from one star within 1.5 deg of $\omega$ Centauri, we find no other stars observed by GALAH spatially near $\omega$ Centauri or the Fimbulthul stream that could be kinematically and chemically linked to the cluster. Chemically tagging stars in the Fimbulthul stream to $\omega$ Centauri confirms the earlier work, and further links this tidal feature in the Milky Way halo to $\omega$ Centauri.

11 pages, 6 figures, accepted to MNRAS

References in corpus (19)

• The Gaia mission
• The GALAH Survey: Scientific Motivation
• The GALAH Survey: Observational Overview and Gaia DR1 companion
• The Streams of the Gaping Abyss: A population of entangled stellar streams surrounding the Inner Galaxy
• Extended stellar systems in the solar neighborhood - II. Discovery of a nearby 120° stellar stream in Gaia DR2
• Fourteen candidate RR Lyrae star streams in the inner Galaxy
• Atypical Mg-poor Milky Way field stars with globular cluster second-generation like chemical patterns
• The GALAH survey: The data reduction pipeline
• The Outer Envelopes of Globular Clusters. II. NGC 1851, NGC 5824 and NGC 1261
• Multi-Object Spectroscopy Field Configuration by Simulated Annealing
• The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo
• The GALAH survey: Chemical Tagging of Star Clusters and New Members in the Pleiades
• Identifying Sagittarius Stream Stars By Their APOGEE Chemical Abundance Signatures
• A Spectroscopic Survey for Omega Centauri Members at and beyond the Cluster Tidal Radius
• Using Gaia DR2 to detect extratidal structures around the Galactic globular cluster NGC362
• Lost and found: evidence of Second Generation stars along the Asymptotic Giant Branch of the globular cluster NGC 6752
• STREGA: STRucture and Evolution of the GAlaxy. I. Survey Overview and First Results
• NGC 6752 AGB Stars Revisited: I. Improved AGB temperatures remove apparent overionisation of Fe I
• Young stars raining through the Galactic Halo: the nature and orbit of Price-Whelan 1

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• On the tidal tails of Milky Way globular clusters
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• The Most Metal-poor Stars in Omega Centauri (NGC 5139)
• Jurassic: A Chemically Anomalous Structure in the Galactic Halo
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• The GALAH Survey: Accreted stars also inhabit the Spite Plateau
• $S^5$: The destruction of a bright dwarf galaxy as revealed by the chemistry of the Indus stellar stream
• Detecting Globular Cluster Tidal Extensions with Bayesian Inference: I. Analysis of $\omega$ Centauri with Gaia EDR3
• The Effect of Dwarf Galaxies on the Tidal Tails of Globular Clusters
• Tidal debris from Omega Centauri discovered with unsupervised machine learning
• Chemical tagging with APOGEE, MUSE, and HST: constraints on the formation of $\omega$ Centauri
• The Nephele ecosystem: stars, globular clusters, and stellar streams associated with the progenitor galaxy of $\omega$ Centauri
• Disruption of a Giant: Spectroscopic Identification of Members in the Periphery and Tidal Tails of $\omega$ Centauri
• Purveyors of fine halos III. Chemical abundance analysis of a potential omega Cen associate