http://arxiv.org/abs/1808.00620
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 $0.06^{0.07}{0.02}$ and $0.13^{0.06}{0.03}$ respectively. Based on the multiplicity of field stars, we obtain an expected binary fraction of $0.12^{0.02}_{0.01}$. 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.
R. Kuruwita, M. Ireland, A. Rizzuto, et. al.
Fri, 3 Aug 18
51/70
Comments: 16 pages, 8 figures, 6 tables, Accepted to MNRAS
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