Journal article
The Galactic Bulge Exploration. III. Calcium Triplet Metallicities for RR Lyrae Stars
The Astronomical journal, Vol.168(3), p.139
09/01/2024
DOI: 10.3847/1538-3881/ad6262
Abstract
RR Lyrae stars (RRLs) are excellent tracers of stellar populations for old, metal-poor components in the the Milky Way and the Local Group. Their luminosities have a metallicity dependence, but determining spectroscopic [Fe/H] metallicities for RRLs, especially at distances outside the solar neighborhood, is challenging. Using 40 RRLs with metallicities derived from both Fe(ii) and Fe(i) abundances, we verify the calibration between the [Fe/H] of RRLs from the calcium triplet. Our calibration is applied to all RRLs with Gaia Radial Velocity Spectrometer (RVS) spectra in Gaia DR3 and to 80 stars in the inner Galaxy from the BRAVA-RR survey. The coadded Gaia RVS RRL spectra provide RRL metallicities with an uncertainty of 0.25 dex, which is a factor of two improvement over the Gaia photometric RRL metallicities. Within our Galactic bulge RRL sample, we find a dominant fraction with low energies without a prominent rotating component. Due to the large fraction of such stars, we interpret these stars as belonging to the in situ metal-poor Galactic bulge component, although we cannot rule out that a fraction of these belong to an ancient accretion event such as Kraken/Heracles.
Details
- Title: Subtitle
- The Galactic Bulge Exploration. III. Calcium Triplet Metallicities for RR Lyrae Stars
- Creators
- Andrea Kunder - ITERZdenek Prudil - European Southern ObservatoryClaire Skaggs - ITERHenrique Reggiani - NSF’s NOIRLabDavid M. Nataf - Johns Hopkins UniversityJoanne Hughes - Seattle UniversityKevin R. Covey - Western Washington UniversityKathryn Devine - College of Idaho
- Resource Type
- Journal article
- Publication Details
- The Astronomical journal, Vol.168(3), p.139
- Publisher
- IOP Publishing Ltd
- DOI
- 10.3847/1538-3881/ad6262
- ISSN
- 0004-6256
- eISSN
- 1538-3881
- Number of pages
- 13
- Grant note
- Heising-Simons Foundation; ACEV Foundation Munich Institute for Astro-, Particle and BioPhysics (MIAPbP) EXC-2094; 390783311 / Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy; German Research Foundation (DFG) AST-2009836 / National Science Foundation; National Science Foundation (NSF) M. J. Murdock Charitable Trust's
- Language
- English
- Date published
- 09/01/2024
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701825702771
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