000005489 001__ 5489
000005489 005__ 20230123212203.0
000005489 0247_ $$2DOI$$a10.1051/0004-6361/202141037
000005489 037__ $$aSCART-2021-0149
000005489 100__ $$aBanyard, G.
000005489 245__ $$aThe observed multiplicity properties of B-type stars in the Galactic young open cluster NGC 6231
000005489 260__ $$c2022
000005489 520__ $$aIt is well known that massive O-stars are frequently (if not always) found in binary or higher-order multiple systems, but this fact has been less robustly investigated for the lower mass range of the massive stars, represented by the B-type stars. Obtaining the binary fraction and orbital parameter distributions of B-type stars is crucial to understand the impact of multiplicity on the archetypal progenitor of core-collapse supernovae as well as to properly investigate formation channels for gravitational wave progenitors. This work aims to characterise the multiplicity of the B-star population of the young open cluster NGC 6231 through multi-epoch optical spectroscopy of 80 B-type stars. We analyse 31 FLAMES/GIRAFFE observations of 80 B-type stars, monitoring their radial velocities (RVs) and performing a least-squares spectral analysis (Lomb-Scargle) to search for periodicity in those stars with statistically significant variability in their RVs. We constrain an observed spectroscopic binary fraction of $33\pm5$% for the B-type stars of NGC 6231, with a first order bias-correction giving a true spectroscopic binary fraction of $52\pm8$%. Out of 27 B-type binary candidates, we obtained orbital solutions for 20 systems: 15 single-lined (SB1) and 5 double-lined spectroscopic binaries (SB2s). We present these orbital solutions and the orbital parameter distributions associated with them. Our results indicate that Galactic B-type stars are less frequently found in binary systems than their more massive O-type counterparts, but their orbital properties generally resemble those of B- and O-type stars in both the Galaxy and Large Magellanic Cloud.
000005489 594__ $$aNO
000005489 6531_ $$abinaries: spectroscopic
000005489 6531_ $$astars: early-type
000005489 6531_ $$astars: massive
000005489 6531_ $$aopen clusters and associations: individual: NGC 6231
000005489 6531_ $$aAstrophysics - Solar and Stellar Astrophysics
000005489 6531_ $$aAstrophysics - Astrophysics of Galaxies
000005489 700__ $$aSana, H.
000005489 700__ $$aMahy, L.
000005489 700__ $$aBodensteiner, J.
000005489 700__ $$aVillaseñor, J. I.
000005489 700__ $$aEvans, C. J.
000005489 773__ $$c28$$nA69$$pAstronomy & Astrophysics$$v658$$y2022
000005489 8560_ $$flaurent.mahy@ksb-orb.be
000005489 8564_ $$s6053206$$uhttp://publi2-as.oma.be/record/5489/files/Banyard_2022_aa41037-21.pdf
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000005489 905__ $$apublished in
000005489 980__ $$aREFERD