English

Multiplicity of disc-bearing stars in Upper Scorpius and Upper Centaurus-Lupus

Earth and Planetary Astrophysics 2018-08-15 v1 Solar and Stellar Astrophysics

Abstract

We present observations of disc-bearing stars in Upper Scorpius (US) and Upper Centaurus-Lupus (UCL) with moderate resolution spectroscopy in order to determine the influence of multiplicity on disc persistence after ~5-20 Myr. Discs were identified using infra-red (IR) excess from the Wide-field Infra-red Survey Explorer (WISE) survey. Our survey consists of 55 US members and 28 UCL members, using spatial and kinematic information to assign a probability of membership. Spectra are gathered from the ANU 2.3m telescope using the Wide Field Spectrograph (WiFeS) to detect radial velocity variations that indicate the presence of a companion. We identify 2 double-lined spectroscopic binaries, both of which have strong IR excess. We find the binary fraction of disc-bearing stars in US and UCL for periods up to 20 years to be 0.060.020.070.06^{0.07}_{0.02} and 0.130.030.060.13^{0.06}_{0.03} respectively. Based on the multiplicity of field stars, we obtain an expected binary fraction of 0.120.010.020.12^{0.02}_{0.01}. The determined binary fractions for disc-bearing stars does not vary significantly from the field, suggesting that the overall lifetime of discs may not differ between single and binary star systems.

Keywords

Cite

@article{arxiv.1808.00620,
  title  = {Multiplicity of disc-bearing stars in Upper Scorpius and Upper Centaurus-Lupus},
  author = {Rajika L. Kuruwita and Michael Ireland and Aaron Rizzuto and Joao Bento and Christoph Federrath},
  journal= {arXiv preprint arXiv:1808.00620},
  year   = {2018}
}

Comments

16 pages, 8 figures, 6 tables, Accepted to MNRAS