Abstract Details

Name: Chirag Chawla
Affiliation: Tata Institute of fundamental Research
Conference ID: ASI2021_444
Title : Gaia may detect hundreds of black holes
Authors and Co-Authors : Chirag Chawla [Tata Institute of Fundamental Research], Sourav Chatterjee [Tata Institute of Fundamental Research], Katelyn Breivik [Center for Computational Astrophysics, Flatiron Institute], Chaithanya Krishnamurthy [Indian Institute of Technology Madras]
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : A large fraction of stellar-mass black holes (BHs) are expected to be in detached binaries with luminous companions (LCs). These BHs are not detectable via traditional methods, e.g., detection via X-ray, radio, or gravitational-wave (GW) emission. We simulate highly realistic models of BH--LC binaries in the Milky Way (MW) using a publicly available binary-population synthesis code COSMIC. We find that Gaia can discover a hundred to a few hundreds of detached BH--LC binaries by monitoring the motions of the LCs during its 10 year observation baseline. Proper motion, parallax, and magnitude of the LCs would also be known from Gaia data, hence, LC properties, such as mass, luminosity, age, and metallicity can be determined relatively easily. Follow-up radial velocity observations to better constrain the BH mass and BH--LC properties are also possible for a majority of these candidates. If found, these BHs will be the first where their mass as well as the metallicity and age of their progenitors will be known almost model-independently. A null result will also provide strong constraints on initial binary properties of high-mass stars and supernova physics. In my talk, I will share our exciting key results.