A new set of chisels for Galactic archaeology: Sc, V and Zn as taggers of accreted globular clusters

Abstract

Chemical tagging is a powerful tool to reveal the origin of stars and globular clusters (GCs), especially when dynamics alone cannot provide robust answers. So far, mostly $\alpha$- and neutron capture elements have been used to distinguish stars born in the Milky Way (MW) from those born in external environments such as that of dwarf galaxies. Here, instead, we use iron-peak elements abundances to investigate the origin of a sample of metal-rich globular clusters. By homogeneously analyzing high-resolution UVES spectra of giant stars belonging to four metal-rich GCs (namely NGC 5927, NGC 6388, NGC 6441, NGC 6496), we find that while the $\alpha$-elements Si and Ca have similar abundance ratios for all the four GCs, and Ti and neutron capture elements (La, Ba and Eu) only show a marginal discrepancy, a stark difference is found when considering the abundances of some iron-peak elements (Sc, V and Zn). In particular, NGC 6388 and NGC 6441 have abundance ratios for these iron-peak elements significantly lower (by ~ 0.5 dex) than those measured in NGC 5927 and NGC 6496, which are clearly identified as born in-situ MW clusters through an analysis of their orbital properties. These measurements indicate that the environment in which these clusters formed is different, and provide robust evidence supporting an accreted origin from the same progenitor for NGC 6388 and NGC 6441.

8 pages, 3 figures, 2 tables, accepted for publication in ApJ Letters

References in corpus (21)

• The Dartmouth Stellar Evolution Database
• Streams, substructures and the early history of the Milky Way
• Kraken reveals itself -- the merger history of the Milky Way reconstructed with the E-MOSAICS simulations
• DAOSPEC: an automatic code for measuring equivalent widths in high-resolution stellar spectra
• Reverse engineering the Milky Way
• Detection of Elements at All Three r-process Peaks in the Metal-Poor Star HD 160617
• The origin and evolution of the odd-Z iron-peak elements Sc, V, Mn, and Co in the Milky Way stellar disk
• The optimally-sampled galaxy-wide stellar initial mass function - Observational tests and the publicly available GalIMF code
• Na-O Anticorrelation and HB. VI. The chemical composition of the peculiar bulge globular cluster NGC 6388
• Na-O Anticorrelation And HB. III. The abundances of NGC 6441 from FLAMES-UVES spectra
• Disentangling the Galactic Halo with APOGEE: II. Chemical and Star Formation Histories for the Two Distinct Populations
• The Similarity of Abundance Ratio Trends and Nucleosynthetic Patterns in the Milky Way Disk and Bulge
• The effects of different Type Ia SN yields on Milky Way chemical evolution
• Facing the problems on the determination of stellar temperatures and gravities: Galactic globular clusters
• Explosive Nucleosynthesis in Near-Chandrasekhar-mass White Dwarf Models for Type Iax Supernovae: Dependence on Model Parameters
• Chemical Study of the Metal-rich Globular Cluster NGC 5927
• A homogeneous comparison between the chemical composition of the Large Magellanic Cloud and the Sagittarius dwarf galaxy
• Detailed Iron-Peak Element Abundances in Three Very Metal-Poor Stars
• Excess of Ca (and Sc) produced in globular cluster multiple populations: a first census in 77 Galactic globular clusters
• The chemical composition of the stellar cluster Gaia1: no surprise behind Sirius
• HERBS II: Detailed chemical compositions of Galactic bulge stars

Cited by in corpus (10)

• Galactic Archaeology with Gaia
• The chemical composition of globular clusters in the Local Group
• Cluster Ages to Reconstruct the Milky Way Assembly (CARMA) I. The final word on the origin of NGC6388 and NGC6441
• Chemistry of multiple stellar populations in the mono-metallic, in situ, bulge globular cluster NGC 6388
• Iron-Peak Element Abundances in Warm Very Metal-Poor Stars
• Chrono-chemodynamical analysis of the globular cluster NGC 6355: Looking for the fundamental bricks of the Bulge
• The in situ origin of the globular cluster NGC 6388 from abundances of Sc, V, and Zn of a large sample of stars
• The Bulge Cluster Origin (BulCO) survey at the ESO-VLT: probing the early history of the Milky Way assembling. Design and first results in Liller1
• Metallicity of the globular cluster NGC 6388 from high resolution spectra of more than 160 giant stars
• Be, V and Cu in the halo star CS 31082-001 from near-UV spectroscopy