COMBS Survey. Metal-poor bulge stars

DOI

The metal-poor stars in the bulge are important relics of the Milky Way's formation history, as simulations predict that they are some of the oldest stars in the Galaxy. In order to determine if they are truly ancient stars, we must understand their origins. Currently, it is unclear if the metal-poor stars in the bulge ([Fe/H]<-1dex) are merely halo interlopers, a unique accreted population, part of the boxy/peanut-shaped bulge, or a classical bulge population. In this work, we use spectra from the VLT/FLAMES spectrograph to obtain metallicity estimates using the Ca-II triplet of 473 bulge stars (187 of which have [Fe/H]50 per cent probability of being bound to the bulge, and half are halo interlopers. We also see that the occurrence rate of halo interlopers increases steadily with decreasing metallicity across the full range of our sample (-3<[Fe/H]<0.5). Our examination of the kinematics of the confined compared to the unbound stars indicates the metal-poor bulge comprises at least two populations; those confined to the boxy/peanut bulge and halo stars passing through the inner galaxy. We conclude that an orbital analysis approach, as we have employed, is important to understand the composite nature of the metal-poor stars in the inner region.

Cone search capability for table J/MNRAS/501/5981/tablea1 (Dynamical properties of our target stars)

Identifier
DOI http://doi.org/10.26093/cds/vizier.75015981
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/501/5981
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/501/5981
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/501/5981
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/501/5981
Provenance
Creator Lucey M.; Hawkins K.; Ness M.; Debattista V.P.; Luna A.; Asplund M.,Bensby T.; Casagrande L.; Feltzing S.; Freeman K.C.; Kobayashi C.,Marino A.F.
Publisher CDS
Publication Year 2021
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Galactic and extragalactic Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy