The Gaia-ESO Survey: new spectroscopic binaries in the Milky Way

Abstract

The Gaia-ESO Survey (GES) is a large public spectroscopic survey which acquired spectra for more than 100000 stars across all major components of the Milky Way. In addition to atmospheric parameters and stellar abundances that have been derived in previous papers of this series, the GES spectra allow us to detect spectroscopic binaries with one (SB1), two (SB2) or more (SBn $\ge$ 3) components. Cross-correlation functions (CCFs) have been re-computed thanks to a dozen spectral masks probing a range of effective temperatures, surface gravities and metallicities. By optimising the mask choice for a given spectrum, the new computed so-called Nacre (Narrow cross-correlation experiment) CCFs are narrower and allow to unblend more stellar components than standard masks. The Doe (Detection of Extrema) extremum-finding code then selects the individual components and provides their radial velocities. From the sample of HR10 and HR21 spectra corresponding to 37565 objects, the present study leads to the detection of 322 SB2, ten (three of them being tentative) SB3, and two tentative SB4. In particular, compared to our previous study, the Nacre CCFs allow us to multiply the number of SB2 candidates by $\approx$ 1.5. The colour-magnitude diagram reveals, as expected, the shifted location of the SB2 main sequence. A comparison between the SB identified in Gaia DR3 and the ones detected in the present work is performed and the complementarity of the two censuses is discussed. An application to mass-ratio determination is presented, and the mass-ratio distribution of the GES SB2 is discussed. When accounting for the SB2 detection rate, an SB2 frequency of $\approx$ 1.4% is derived within the present stellar sample of mainly FGK-type stars. As primary outliers identified within the GES data, SBn spectra produce a wealth of information and useful constraints for the binary population synthesis studies.

References in corpus (24)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Gaia Data Release 3: Summary of the content and survey properties
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The GALAH Survey: Scientific Motivation
• Gaia Early Data Release 3: Photometric content and validation
• Gaia Data Release 3 Properties and validation of the radial velocities
• Gaia Data Release 3: Stellar multiplicity, a teaser for the hidden treasure
• Gaia Data Release 3: Astrophysical parameters inference system (Apsis) I -- methods and content overview
• Gaia Data Release 3: Analysis of the Gaia BP/RP spectra using the General Stellar Parameterizer from Photometry
• The Gaia-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy
• Gaia Data Release 3: Catalogue Validation
• The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products
• A Unicorn in Monoceros: the $3M_{\odot }$ dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate
• The Gaia-ESO Survey: processing of the FLAMES-UVES spectra
• Signatures of unresolved binaries in stellar spectra: implications for spectral fitting
• Gaia DR3: Apsis III -- Non-stellar content and source classification
• The Gaia-ESO Survey: double, triple and quadruple-line spectroscopic binary candidates
• Double-lined Spectroscopic Binary Stars in the Radial Velocity Experiment Survey
• Unicorns and Giraffes in the binary zoo: stripped giants with subgiant companions
• Discovery of Cycle-to-cycle Modulated Spectral Line Variability and Velocity Gradients in Long-period Cepheids
• The Spectroscopic Binaries from LAMOST Medium-Resolution Survey (MRS). I. Searching for Double-lined Spectroscopic Binaries (SB2s) with Convolutional Neural Network
• IN-SYNC VI. Identification and Radial Velocity Extraction for 100+ Double-Lined Spectroscopic Binaries in the APOGEE/IN-SYNC Fields
• The Gaia-ESO Survey: detection and characterization of single line spectroscopic binaries