TY - JOUR
T1 - Gaia's brightest very metal-poor (VMP) stars
T2 - A metallicity catalogue of a thousand VMP stars from Gaia RVS spectra
AU - Viswanathan, Akshara
AU - Starkenburg, Else
AU - Matsuno, Tadafumi
AU - Venn, Kim A.
AU - Martin, Nicolas F.
AU - Longeard, Nicolas
AU - Ardern-Arentsen, Anke
AU - Carlberg, Raymond G.
AU - Fabbro, Sebastien
AU - Kordopatis, Georges
AU - Montelius, Martin
AU - Sestito, Federico
AU - Yuan, Zhen
N1 - Submitted to A&A. 11 pages, 4 pages appendix, 5 figures. Catalogue is made available public here: https://astroakshara.github.io/rvs-paper/Gaia-RVS-VMP-catalogue-AV23b-vSep23.csv Feel free to use it to do amazing science with the amazing data Gaia has given us
PY - 2023/9/12
Y1 - 2023/9/12
N2 - Context. Gaia DR3 has offered the scientific community a remarkable dataset of approximately one million spectra acquired with the Radial Velocity Spectrometer (RVS) in the Calcium II triplet region, that is well-suited to identify very metal-poor (VMP) stars. However, over 40% of these spectra have no released parameters by Gaia's GSP Spec pipeline in the domain of VMP stars, whereas VMP stars are key tracers of early Galactic evolution. Aims. We aim to provide spectroscopic metallicities for VMP stars using Gaia RVS spectra, thereby producing a catalogue of bright VMP stars distributed over the full sky that can serve as the basis to study early chemical evolution throughout the Galaxy. Methods. We select VMP stars using photometric metallicities from the literature and analyse the Gaia RVS spectra to infer spectroscopic metallicities for these stars. Results. The inferred metallicities agree very well with literature high-resolution metallicities with a median systematic offset of 0.1 dex and standard deviation of $\sim$0.15 dex. The purity of this sample in the VMP regime is $\sim$80% with outliers representing a mere $\sim$3%. Conclusions. We make available an all-sky catalogue of $\sim$1500 stars with reliable spectroscopic metallicities down to [Fe/H]$\sim$-4.0, of which $\sim$1000 are VMP stars. More than 75% of these stars have either no metallicity value in the literature to date or are flagged to be unreliable in their literature metallicity estimates. This catalogue of bright (G
AB - Context. Gaia DR3 has offered the scientific community a remarkable dataset of approximately one million spectra acquired with the Radial Velocity Spectrometer (RVS) in the Calcium II triplet region, that is well-suited to identify very metal-poor (VMP) stars. However, over 40% of these spectra have no released parameters by Gaia's GSP Spec pipeline in the domain of VMP stars, whereas VMP stars are key tracers of early Galactic evolution. Aims. We aim to provide spectroscopic metallicities for VMP stars using Gaia RVS spectra, thereby producing a catalogue of bright VMP stars distributed over the full sky that can serve as the basis to study early chemical evolution throughout the Galaxy. Methods. We select VMP stars using photometric metallicities from the literature and analyse the Gaia RVS spectra to infer spectroscopic metallicities for these stars. Results. The inferred metallicities agree very well with literature high-resolution metallicities with a median systematic offset of 0.1 dex and standard deviation of $\sim$0.15 dex. The purity of this sample in the VMP regime is $\sim$80% with outliers representing a mere $\sim$3%. Conclusions. We make available an all-sky catalogue of $\sim$1500 stars with reliable spectroscopic metallicities down to [Fe/H]$\sim$-4.0, of which $\sim$1000 are VMP stars. More than 75% of these stars have either no metallicity value in the literature to date or are flagged to be unreliable in their literature metallicity estimates. This catalogue of bright (G
KW - astro-ph.GA
U2 - 10.1051/0004-6361/202347944
DO - 10.1051/0004-6361/202347944
M3 - Article
SN - 0004-6361
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
ER -