Before stellar-mass black holes merge in a spectacular burst of gravitational waves, they’re locked in a fatal dance around each other as a binary black hole. A new study uses clues from black hole spins to explore how these binaries came to be paired together in the first place.
To Build a Binary
The Hanford (top) and Livingston (bottom) LIGO facilities, which work together to detect gravitational-wave signals. [Caltech/MIT/LIGO Lab]With ten detections of merging stellar-mass black holes made by the LIGO/Virgo gravitational-wave observatories in just their first two observing runs, these detectors have opened a new window through which we can study the evolution of massive stars.
Among the open questions we hope to answer with these and future detections is the following: How were these binary pairs of stellar-mass black holes created? There are two main formation channels proposed:
Field binary evolution
In isolation in the galactic field, the two members of a binary star system independently evolve into black holes, and they remain bound to each other through this process.
Black holes are formed independently and then sink to the centers of high stellar density environments like globular clusters. There, dynamical interactions cause them to pair ...