Gravitational-wave Astrophysics: BH-BH/NS-NS mergers with LIGO/Virgo

I will discuss the astrophysical importance of the recent LIGO/Virgo direct detections of gravitational-waves. Despite the fact that massive BH-BH dominance in gravitational-wave signal was predicted prior the detections, it is not at all clear which one of the several formation scenarios produces these massive mergers. This inhibits astrophysical information inference from LIGO/Virgo observations, as conclusions are different within each formation scenario. There is quite an opposite problem with the recent detection of NS-NS merger in an old elliptical host galaxy. None of the formation channels that can reproduce basic properties of the detected BH-BH mergers, can recover the NS-NS merger rate estimated by LIGO/Virgo. Despite the fact that the exact origin of LIGO/Virgo sources is not yet known, several astrophysical implications are beginning to emerge.