The Pristine survey II: a sample of bright stars observed with FEROS

Abstract

Extremely metal-poor (EMP) stars are old objects formed in the first Gyr of the Universe. They are rare and, to select them, the most successful strategy has been to build on large and low-resolution spectroscopic surveys. The combination of narrow- and broad band photometry provides a powerful and cheaper alternative to select metal-poor stars. The on-going Pristine Survey is adopting this strategy, conducting photometry with the CFHT MegaCam wide field imager and a narrow-band filter centred at 395.2 nm on the CaII-H and -K lines. In this paper we present the results of the spectroscopic follow-up conducted on a sample of 26 stars at the bright end of the magnitude range of the Survey (g<=15), using FEROS at the MPG/ESO 2.2 m telescope. From our chemical investigation on the sample, we conclude that this magnitude range is too bright to use the SDSS gri bands, which are typically saturated. Instead the Pristine photometry can be usefully combined with the APASS gri photometry to provide reliable metallicity estimates.

AN accepted

References in corpus (13)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The Milky Way Tomography with SDSS: II. Stellar Metallicity
• Carbon Enhanced Metal-Poor Stars. I. Chemical Compositions of 26 Stars
• First Stars VIII -- Enrichment of the neutron-capture elements in the early Galaxy
• Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars
• The stellar content of the Hamburg/ESO survey. IV. Selection of candidate metal-poor stars
• Simulating cosmic metal enrichment by the first galaxies
• Atomic and Molecular Data for Optical Stellar Spectroscopy
• MARCS model atmospheres
• Newly Discovered RR Lyrae Stars in the SDSSXPanXSTARRS1XCatalina Footprint
• The uvbyHbeta Metallicity Calibration for G and K Dwarfs
• Carbon-rich RR Lyr type stars
• Chemical abundances of the metal-poor horizontal-branch stars CS 22186-005 and CS 30344-033

Cited by in corpus (14)

• The Pristine survey VIII: The metallicity distribution function of the Milky Way halo down to the extremely metal-poor regime
• Pristine IX: CFHT ESPaDOnS Spectroscopic Analysis of 115 Bright Metal-Poor Candidate Stars
• The Pristine survey -- XXIII. Data Release 1 and an all-sky metallicity catalogue based on Gaia DR3 BP/RP spectro-photometry
• The Pristine survey -- XII: Gemini-GRACES chemo-dynamical study of newly discovered extremely metal-poor stars in the Galaxy
• The Pristine survey XIII: Uncovering the very metal-poor tail of the thin disc
• The Pristine Inner Galaxy Survey (PIGS) III: carbon-enhanced metal-poor stars in the bulge
• Cosmic nucleosynthesis: a multi-messenger challenge
• The Pristine survey -- VII. A cleaner view of the Galactic outer halo using blue horizontal branch stars
• The Pristine survey -- XV. A CFHT ESPaDOnS view on the Milky Way halo and disc populations
• The Pristine survey -- XVII. The C-19 stream is dynamically hot and more extended than previously thought
• The Pristine survey XIV: chemical analysis of two ultra-metal-poor stars
• The Pristine survey: XXV. The very metal-poor Galaxy: Chemodynamics through the follow-up of the Pristine-Gaia synthetic catalogue
• The peculiar abundances of HE 1005-1439. A carbon-enhanced extremely metal-poor star contaminated with products of both s-and i-process nucleosynthesis
• The Pristine Survey -- XXVII. Journey to the Galactic outskirts -- Mapping the outer halo red giant stars down to the very metal-poor end