Forty-four new and known M-dwarf multiples in the SDSS-III/APOGEE M-dwarf ancillary science sample. (2018)
Keywords :
binaries close - binaries: general - binaries: spectroscopic - stars: formation - stars: low-mass
Abstract:Binary stars make up a significant portion of all stellar systems. Consequently, an understanding of the bulk properties of binary stars is necessary for a full picture of star formation. Binary surveys indicate that both multiplicity fraction and typical orbital separation increase as functions of primary mass. Correlations with higher-order architectural parameters such as mass ratio are less well constrained. We seek to identify and characterize double-lined spectroscopic binaries (SB2s) among the 1350 M-dwarf ancillary science targets with APOGEE spectra in the SDSS-III Data Release 13. We measure the degree of asymmetry in the APOGEE pipeline cross-correlation functions (CCFs) and use those metrics to identify a sample of 44 high-likelihood
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The SDSS-III (Eisenstein et al. 2011AJ....142...72E) APOGEE M-dwarf
ancillary program (Deshpande et al. 2013, J/AJ/146/156; Holtzman et al.
2015AJ....150..148H) was designed to produce a large, homogeneous spectral
library and kinematic catalog of nearby low-mass stars; these data products
are useful for investigations of stellar astrophysics (e.g., Souto et al.
2017ApJ...835..239S; Gilhool et al. 2018, J/AJ/155/38) and refining
targeting procedures for current and future exoplanet search programs.
These science goals are uniquely enabled by the APOGEE spectrograph
(Wilson et al. 2010SPIE.7735E..1CW, 2012SPIE.8446E..0HW), which acquires
high-resolution (R~22000) near-infrared spectra from each of 300 optical
fibers. As deployed at the 2.5 m SDSS telescope (Gunn et al.
2006AJ....131.2332G), the APOGEE spectrograph achieves a field of view
with a diameter of 3{deg}, making it a highly efficient instrument for
surveying the stellar parameters of the constituents of Galactic stellar
populations (Majewski et al. 2017AJ....154...94M). The SDSS DR13 data
release (Albareti et al. 2017ApJS..233...25A) includes 7152 APOGEE spectra
of 1350 stars targeted by this ancillary program.
We used the TODCOR algorithm (Zucker & Mazeh 1994ApJ...420..806Z) to
measure RVs from all HET/HRS spectra and any APOGEE spectra flagged
with low-RV separations. This TODCOR analysis followed the procedures
previously discussed by Bender et al. (2005AJ....129..402B) and used the
algorithm implementation of Bender et al. (2012ApJ...751L..31B).
