Evidence for C and Mg variations in the GD-1 stellar stream

Abstract

Dynamically cold stellar streams are the relics left over from globular cluster dissolution. These relics offer a unique insight into a now fully disrupted population of ancient clusters in our Galaxy. Using a combination of Gaia eDR3 proper motions, optical and near-UV colours we select a sample of likely Red Giant Branch stars from the GD-1 stream for medium-low resolution spectroscopic follow-up. Based on radial velocity and metallicity, we are able to find 14 new members of GD-1, 5 of which are associated with the \emph{spur} and \emph{blob/cocoon} off-stream features. We measured C-abundances to probe for abundance variations known to exist in globular clusters. These variations are expected to manifest in a subtle way in globular clusters with such low masses ($\sim 10^4{\mathrm{M}}_{\odot }$) and metallicities ($[Fe/H]\sim -2.1\mathrm{dex}$). We find that the C-abundances of the stars in our sample display a small but significant ($3\sigma$ level) spread. Furthermore, we find $\sim 3\sigma$ variation in Mg-abundances among the stars in our sample that have been observed by APOGEE. These abundance patterns match the ones found in Galactic globular clusters of similar metallicity. Our results suggest that GD-1 represents another fully disrupted low mass globular cluster where light-element abundance spreads have been found.

12 pages, 7 figures. Accepted to MNRAS

References in corpus (33)

• The NumPy array: a structure for efficient numerical computation
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. IX. The Atlas of Multiple Stellar Populations
• Spectroscopic and Photometric evidence of two stellar populations in the Galactic Globular Cluster NGC6121 (M4)
• Detection of a 63 Degree Cold Stellar Stream in the Sloan Digital Sky Survey
• Carbon-Enhanced Metal-Poor Star Frequencies in the Galaxy: Corrections for the Effect of Evolutionary Status on Carbon Abundances
• What is a globular cluster? An observational perspective
• Globular Cluster Streams as Galactic High-Precision Scales - The Poster Child Palomar 5
• The Streams of the Gaping Abyss: A population of entangled stellar streams surrounding the Inner Galaxy
• A Synoptic Map of Halo Substructures from the Pan-STARRS1 3π Survey
• The Southern Stellar Stream Spectroscopic Survey (S5): Chemical Abundances of Seven Stellar Streams
• Comparing CN and CH Line Strengths in a Homogeneous Spectroscopic Sample of 8 Galactic Globular Clusters
• Multiple populations in globular clusters: the distinct kinematic imprints of different formation scenarios
• The Outer Envelopes of Globular Clusters. II. NGC 1851, NGC 5824 and NGC 1261
• Sodium and Oxygen Abundances in the Open Cluster NGC 6791 from APOGEE H-Band Spectroscopy
• Deep Mixing and Metallicity: Carbon Depletion in Globular Cluster Giants
• Searching for Chemical Signatures of Multiple Stellar Populations in the Old, Massive Open Cluster NGC 6791
• The eye of Gaia on globular clusters structure: tidal tails
• Accretion of pristine gas and dilution during the formation of multiple-population globular clusters
• NGC 6535: the lowest mass Milky Way globular cluster with a Na-O anti-correlation? Cluster mass and age in the multiple population context
• A family picture: tracing the dynamical path of the structural properties of multiple populations in globular clusters
• Radial distributions of sub-populations in the globular cluster M15: a more centrally concentrated primordial population
• The tidal remnant of an unusually metal-poor globular cluster
• Evidence for multiple populations in the intermediate age cluster Lindsay 1 in the SMC
• The Relationship Between Globular Cluster Mass, Metallicity, and Light Element Abundance Variations
• Globular Cluster Formation at High Density: A model for Elemental Enrichment with Fast Recycling of Massive-Star Debris
• Purveyors of fine halos: Re-assessing globular cluster contributions to the Milky Way halo build-up with SDSS-IV
• O, Na, Ba and Eu abundance patterns in open clusters
• CN Bimodality at Low Metallicity: The Globular Cluster M53
• Purveyors of fine halos. II. Chemodynamical association of halo stars with Milky Way globular clusters
• Spectroscopic detection of multiple populations in the ~2 Gyr old cluster Hodge 6 in the LMC
• ESO452-SC11: The lowest mass globular cluster with a potential chemical inhomogeneity
• Light Element Discontinuities Suggest an Early Termination of Star Formation in the Globular Cluster NGC 6402 (M14)
• On the Nitrogen variation in ~2 Gyr old massive star clusters in the Large Magellanic Cloud

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