Astrometric mass measurement of compact companions in binary systems with Gaia

Abstract

For binary systems with an unseen primary and a luminous secondary, the astrometric wobble of the secondary could be used to study the primary. With Gaia, it is possible to measure the mass of the black hole or neutron star with a luminous companion (hereafter BH/NS-LC). Our aim is to provide a method for predicting Gaia's ability in measuring the mass of BH/NS-LCs. We also tried to estimate the number of solvable BH/NS-LCs using Gaia. We used a realistic Markov chain Monte Carlo simulation of mock Gaia observations to obtain a relation between the uncertainty of mass measurement of the primary in BH/NS-LCs with the observable variables of the secondary astrometric orbit. Furthermore, we used the MOBSE code to evolve a Galactic BH/NS-LC sample with a combined Milky Way model. Our relation is applied to this sample to estimate the number of solvable BH/NS-LCs. We derived a good relation between the mass uncertainty and the binary parameters. For the first time, we show the quantitive influence of the period P, inclination i, eccentricity e, and ecliptic latitude $\beta$ to the mass measurement. Our results suggest that $48_{-7}^{+7}$ BH-LCs and $102_{10}^{+11}$ NS-LCs are solvable during a 5 yr Gaia mission. We also give the distribution of the distance and apparent magnitude of the Gaia solvable BH/NS-LCs. This solvable sample would be increased by additional spectroscopic data or a prolonged Gaia mission. The mass uncertainty relation could be used in future simulations of BH/NS-LCs observed by Gaia. The prediction of the solvable BH/NS-LCs is not only influenced by the process in generating the Galactic BH/NS-LC sample, but is also affected by our uncertainty relation. In particular, the relations of parameters such as $[P,e,i,\beta ]$ are very useful to correct the selection effect in the statistic results of the future BH/NS-LC sample observed by Gaia.

References in corpus (17)

• The Gaia mission
• Binary interaction dominates the evolution of massive stars
• Southern Massive Stars at High Angular Resolution: Observational Campaign and Companion Detection
• The Optical to Mid-Infrared Extinction Law Based on the APOGEE, Gaia DR2, Pan-STARRS1, SDSS, APASS, 2MASS and WISE Surveys
• Astrometric exoplanet detection with Gaia
• Merging black hole binaries: the effects of progenitor's metallicity, mass-loss rate and Eddington factor
• Parallax Systematics and Photocenter Motions of Benchmark Eclipsing Binaries in Gaia EDR3
• On the Shoulders of Giants: Properties of the Stellar Halo and the Milky Way Mass Distribution
• A wide star-black-hole binary system from radial-velocity measurements
• The total stellar halo mass of the Milky Way
• YBC, a stellar bolometric corrections database with variable extinction coefficients: an application to PARSEC isochrones
• Double-blind test program for astrometric planet detection with Gaia
• Revealing black holes with Gaia
• Gaia May Detect Hundreds of Well-characterised Stellar Black Holes
• The observed mass distribution of Galactic black hole LMXBs is biased against massive black holes
• Contact Binaries as Viable Distance Indicators: New, Competitive (V)JHKs Period-Luminosity Relations
• Detectablity of Black Hole Binaries with Gaia: Dependence on Binary Evolution Models

Cited by in corpus (2)

• A non-interacting Galactic black hole candidate in a binary system with a main-sequence star
• An upper limit on the frequency of short-period black hole companions to Sun-like stars