Close companions around young stars

DOI

Multiplicity is a fundamental property that is set early during stellar lifetimes, and it is a stringent probe of the physics of star formation. The distribution of close companions around young stars is still poorly constrained by observations. We present an analysis of stellar multiplicity derived from Apache Point Observatory Galactic Evolution Experiment-2 spectra obtained in targeted observations of nearby star-forming regions. This is the largest homogeneously observed sample of high-resolution spectra of young stars. We developed an autonomous method to identify double-lined spectroscopic binaries (SB2s). Out of 5007 sources spanning the mass range of ~0.05-1.5 M_{sun}, we find 399 binaries, including both radial velocity (RV) variables and SB2s. The mass ratio distribution of SB2s is consistent with being uniform for q0.95. The period distribution is consistent with what has been observed in close binaries (<10 au) in the evolved populations. Three systems are found to have q~0.1, with a companion located within the brown dwarf desert. There are no strong trends in the multiplicity fraction as a function of cluster age from 1 to 100 Myr. There is a weak dependence on stellar density, with companions being most numerous at {Sigma}*_~30 stars/pc^-2^ and decreasing in more diffuse regions. Finally, disk-bearing sources are deficient in SB2s (but not RV variables) by a factor of ~2; this deficit is recovered by the systems without disks. This may indicate a quick dispersal of disk material in short-period equal-mass systems that is less effective in binaries with lower q.

Cone search capability for table J/AJ/157/196/table1 (Catalog of the sources observed by APOGEE-2 survey towards the young clusters and star-forming regions)

Cone search capability for table J/AJ/157/196/table3 (Observed clusters and star-forming regions)

Identifier
DOI http://doi.org/10.26093/cds/vizier.51570196
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/AJ/157/196
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/157/196
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/157/196
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/AJ/157/196
Provenance
Creator Kounkel M.; Covey K.; Moe M.; Kratter K.M.; Suarez G.; Stassun K.G.,Roman-Zuniga C.; Hernandez J.; Kim J.S.; Ramirez K.P.; Roman-Lopes A.,Stringfellow G.S.; O Jaehnig K.; Borissova J.; Tofflemire B.,Krolikowski D.; Rizzuto A.; Kraus A.; Badenes C.; Longa-Pena P.,Maqueo Chew Y.G.; Barba R.; Nidever D.L.; Brown C.; De Lee N.; Pan K.,Bizyaev D.; Oravetz D.; Oravetz A.
Publisher CDS
Publication Year 2019
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Galactic and extragalactic Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy