TY - JOUR
T1 - The close binary fraction as a function of stellar parameters in APOGEE
T2 - A strong anticorrelation with α abundances
AU - Mazzola, Christine N.
AU - Badenes, Carles
AU - Moe, Maxwell
AU - Koposov, Sergey E.
AU - Kounkel, Marina
AU - Kratter, Kaitlin
AU - Covey, Kevin
AU - Walker, Matthew G.
AU - Thompson, Todd A.
AU - Andrews, Brett
AU - Freeman, Peter E.
AU - Anguiano, Borja
AU - Carlberg, Joleen K.
AU - De Lee, Nathan M.
AU - Frinchaboy, Peter M.
AU - Lewis, Hannah M.
AU - Majewski, Steven
AU - Nidever, David
AU - Nitschelm, Christian
AU - Price-Whelan, Adrian M.
AU - Roman-Lopes, Alexandre
AU - Stassun, Keivan G.
AU - Troup, Nicholas W.
N1 - Funding Information:
CNM acknowledges support from Scialog Scholar grant 24215 from the Research Corporation. CNM and CB acknowledge support from the National Science Foundation grant AST-1909022. SEK and MGW acknowledge support from the National Science Foundation grant AST-1909584. MM and KK acknowledge support from National Aeronautics and Space Administration grant 80NSSC18K0726 and the Research Corporation for Science Advancement grant ID# 26077. BA, HML, and SM acknowledge support from National Science Foundation grant AST-1616636. NMD would like to acknowledge that this material is based upon work supported by the National Science Foundation under grant no. 1616684.
Publisher Copyright:
© 2020 The Author(s).
PY - 2020/12/1
Y1 - 2020/12/1
N2 - We use observations from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey to explore the relationship between stellar parameters and multiplicity. We combine high-resolution repeat spectroscopy for 41 363 dwarf and subgiant stars with abundance measurements from the APOGEE pipeline and distances and stellar parameters derived using Gaia DR2 parallaxes from Sanders & Das to identify and characterize stellar multiples with periods below 30 yr, corresponding to ΔRVmax ≳ 3 km s-1, where ΔRVmax is the maximum APOGEE-detected shift in the radial velocities. Chemical composition is responsible for most of the variation in the close binary fraction in our sample, with stellar parameters like mass and age playing a secondary role. In addition to the previously identified strong anticorrelation between the close binary fraction and [Fe/H], we find that high abundances of α elements also suppress multiplicity at most values of [Fe/H] sampled by APOGEE. The anticorrelation between α abundances and multiplicity is substantially steeper than that observed for Fe, suggesting C, O, and Si in the form of dust and ices dominate the opacity of primordial protostellar discs and their propensity for fragmentation via gravitational stability. Near [Fe/H] = 0 dex, the bias-corrected close binary fraction (a < 10 au) decreases from ≈100 per cent at [α/H] = -0.2 dex to ≈15 per cent near [α/H] = 0.08 dex, with a suggestive turn-up to ≈20 per cent near [α/H] = 0.2. We conclude that the relationship between stellar multiplicity and chemical composition for sun-like dwarf stars in the field of the Milky Way is complex, and that this complexity should be accounted for in future studies of interacting binaries.
AB - We use observations from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey to explore the relationship between stellar parameters and multiplicity. We combine high-resolution repeat spectroscopy for 41 363 dwarf and subgiant stars with abundance measurements from the APOGEE pipeline and distances and stellar parameters derived using Gaia DR2 parallaxes from Sanders & Das to identify and characterize stellar multiples with periods below 30 yr, corresponding to ΔRVmax ≳ 3 km s-1, where ΔRVmax is the maximum APOGEE-detected shift in the radial velocities. Chemical composition is responsible for most of the variation in the close binary fraction in our sample, with stellar parameters like mass and age playing a secondary role. In addition to the previously identified strong anticorrelation between the close binary fraction and [Fe/H], we find that high abundances of α elements also suppress multiplicity at most values of [Fe/H] sampled by APOGEE. The anticorrelation between α abundances and multiplicity is substantially steeper than that observed for Fe, suggesting C, O, and Si in the form of dust and ices dominate the opacity of primordial protostellar discs and their propensity for fragmentation via gravitational stability. Near [Fe/H] = 0 dex, the bias-corrected close binary fraction (a < 10 au) decreases from ≈100 per cent at [α/H] = -0.2 dex to ≈15 per cent near [α/H] = 0.08 dex, with a suggestive turn-up to ≈20 per cent near [α/H] = 0.2. We conclude that the relationship between stellar multiplicity and chemical composition for sun-like dwarf stars in the field of the Milky Way is complex, and that this complexity should be accounted for in future studies of interacting binaries.
KW - binaries: close
KW - binaries: spectroscopic
KW - stars: abundances
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U2 - 10.1093/mnras/staa2859
DO - 10.1093/mnras/staa2859
M3 - Article
AN - SCOPUS:85096941382
SN - 0035-8711
VL - 499
SP - 1607
EP - 1626
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -