Vol. 594
In section 2. Astrophysical processes

The effect of pair-instability mass loss on black-hole mergers

Detection of a gravitational wave signal by the LIGO collaboration has tantalised the scientific community. Two black hole-black hole (BH) binary mergers were detected, one with heavy objects (30 times the mass of our Sun) and more with more normal objects (~10 solar masses). More events are anticipated for the next LIGO run, when the VIRGO detector will also start its search for gravitational waves. In this paper, based on detailed stellar population simulations, the authors predict that no binary BHs can be formed that are heavier than ~50 solar masses each. Predictions for the next LIGO-VIRGO O2 run span a range of 2-70 events.