Revealing black holes with Gaia

Understand

We estimate the population of black holes with luminous stellar companions (BH-LCs) in the Milky Way (MW) observable by Gaia.

• We evolve a realistic distribution of BH-LC progenitors from zero-age to the current epoch taking into account relevant physics, including binary stellar evolution, BH-formation physics, and star formation rate, to estimate the BH-LC population in the MW today.
• We predict that Gaia will discover between 3800 and 12,000 BH-LCs by the end of its 5 yr mission, depending on BH natal kick strength and observability constraints.
• We find that the overall yield, and distributions of eccentricities and masses of observed BH-LCs can provide important constraints on the strength of BH natal kicks.