A Sample of Compact Object Candidates in Single-lined Spectroscopic Binaries from LAMOST Medium-resolution Survey

Abstract

The stellar spectra from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) medium-resolution survey can be used to search for compact objects in binaries. The LAMOST Data Release 10 catalog includes >980,000 targets with multiple medium-resolution spectra. We select the targets with large or rapid radial-velocity variation, and obtained an input sample of 1822 sources. We use light curves and spectra to identify and exclude eclipsing binaries and double-lined spectroscopic binaries in the input sample. We finally derive a catalog of 89 candidates with well-folded radial velocity, which are all single-lined spectroscopic binaries, indicating an unseen companion residing in each system. The mass function of each system can be well constrained based on the radial-velocity curve. In our sample, 26 sources have mass function higher than 0.1 M ⊙, among which 18 sources have ellipsoidal-type light curves. In our opinion, compact objects are likely existent in all these 26 binaries, which are worth follow-up identification.