LTD064402+245919: A Subgiant with a 1-3 M${}_{\odot }$ Undetected Companion Identified from LAMOST-TD Data

Abstract

Single-line spectroscopic binaries recently contribute to the stellar-mass black hole discovery, independently of the X-ray transient method. We report the identification of a single-line binary system LTD064402+245919, with an orbital period of 14.50 days. The observed component is a subgiant with a mass of 2.77$\pm$0.68M${}_{\odot }$, radius 15.5$\pm$2.5R${}_{\odot }$, effective temperature $T_{\mathrm{eff}}$ 4500$\pm$200K, and surface gravity log\emph{g} 2.5$\pm$0.25dex. The discovery makes use of the LAMOST time-domain (LAMOST-TD) and ZTF survey. Our general-purpose software pipeline applies the Lomb-Scargle periodogram to determine the orbital period and uses machine-learning to classify the variable type from the folded light curves. We apply a combined model to estimate the orbital parameters from both the light and radial velocity curves, taking constraints on the primary star mass, mass function, and detection limit of secondary luminosity into consideration. We obtain a radial velocity semi-amplitude of 44.6$\pm$1.5 km s${}^{-1}$, mass ratio of 0.73$\pm$0.07, and an undetected component mass of 2.02$\pm$0.49M${}_{\odot }$ when the type of the undetected component is not set. We conclude that the inclination is not well constrained, and that the secondary mass is larger than 1M${}_{\odot }$ when the undetected component is modelled as a compact object. According to our investigations using an MCMC simulation, increasing the spectra SNR by a factor of 3 would enable the secondary light to be distinguished (if present). The algorithm and software in this work are able to serve as general-purpose tools for the identification of compact objects quiescent in X-rays.

arXiv commentAccepted by ApJ

References in corpus (50)

• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• First Results from the Catalina Real-time Transient Survey
• A Computational Guide to Physics of Eclipsing Binaries. Paper I. Demonstrations and Perspectives
• The Chandra Source Catalog
• The XMM-Newton Serendipitous Survey. V. The Second XMM-Newton Serendipitous Source Catalogue
• A Three-Dimensional Map of Milky-Way Dust
• The ASAS-SN Catalog of Variable Stars I: The Serendipitous Survey
• Revised Catalog of GALEX Ultraviolet Sources. I. The All-sky Survey: GUVcat_AIS
• BlackCAT: A catalogue of stellar-mass black holes in X-ray transients
• The Neutron Star and Black Hole Initial Mass Function
• Discovery of a Candidate Black Hole - Giant Star Binary System in the Galactic Field
• Periodograms for Multiband Astronomical Time Series
• Mass Measurements of Black Holes in X-Ray Transients: Is There a Mass Gap?
• Physics of Eclipsing Binaries. V. General Framework for Solving the Inverse Problem
• A wide star-black-hole binary system from radial-velocity measurements
• Eclipsing binaries in ASAS catalog
• Puzzling accretion onto a black hole in the ultraluminous X-ray source M101 ULX-1
• The LAMOST Stellar Parameter Pipeline at Peking University --- LSP3
• Pulsating red giant stars in eccentric binary systems discovered from Kepler space-based photometry
• Discovery and Characterization of 3000+ Main-Sequence Binaries from APOGEE Spectra
• Deriving the stellar labels of LAMOST spectra with Stellar LAbel Machine (SLAM)
• Self-consistent Stellar Radial Velocities from LAMOST Medium-Resolution Survey (MRS) DR7
• The EPOCH Project: I. Periodic variable stars in the EROS-2 LMC database
• The ASAS-SN Catalog of Variable Stars V: Variables in the Southern Hemisphere
• A Package for the Automated Classification of Periodic Variable Stars
• Empirical Bolometric Correction Coefficients for Nearby Main-Sequence Stars in Gaia Era
• A collection of model stellar spectra for spectral types B to early-M
• Phase II of the LAMOST-Kepler/K2 survey. I. Time series of medium-resolution spectroscopic observations
• Ages and Masses of 0.64 million Red Giant Branch stars from the LAMOST Galactic Spectroscopic Survey
• Distances of Galactic Supernova Remnants Using Red Clump Stars
• Prospects of Finding Detached Black Hole-Star Binaries with TESS
• Population Synthesis of Galactic Be-star Binaries with A Helium-star Companion
• Non-interacting black hole binaries with Gaia and LAMOST
• A Method to Search for Black Hole Candidates with Giant Companions by LAMOST
• Exploring the spectral \textit{information content} in the LAMOST medium-resolution survey (MRS)
• Phase-dependent study of near-infrared disk emission lines in LB-1
• The UV Emission of Stars in LAMOST Survey I. Catalogs
• Mining for Candidates of Galactic Stellar-mass Black Hole Binaries with LAMOST
• Searching for Black Hole Candidates by LAMOST and ASAS-SN
• A Catalog of Short Period Spectroscopic and Eclipsing Binaries Identified from the LAMOST & PTF Surveys
• Optimizing Automated Classification of Periodic Variable Stars in New Synoptic Surveys
• Zwicky Transient Facility and Globular Clusters: the Period-Luminosity and Period-Luminosity-Color Relations for Late-Type Contact Binaries
• An Empirical Bayesian Approach to Limb-darkening in Modeling WASP-121b Transit Light Curves
• Galaxy Optical Variability of Virgo Cluster: New Tracer for Environmental Influences on Galaxies

Cited by in corpus (4)

• The Spectroscopic Binaries from LAMOST Medium-Resolution Survey (MRS). I. Searching for Double-lined Spectroscopic Binaries (SB2s) with Convolutional Neural Network
• A White Dwarf-Main Sequence Binary Unveiled by Time-Domain Observations from LAMOST and TESS
• TESS Timings of 31 Hot Jupiters with Ephemeris Uncertainties
• Searching for Compact Object Candidates from LAMOST Time-Domain Survey of Four K2 Plates