Attività del Dipartimento

Gravitational waves and the dawn of multimessenger astrophysics

Gianluca Gemme

On August 14, 2017 Advanced LIGO and Advanced Virgo detected the first triple-coincident merger of a binary black hole system, GW170814, demonstrating the best-ever localization of gravitational-wave source on the sky and making the first direct polarization measurement of a gravitational wave signal. Three days later, the same detectors recorded for the first time the signal from a merger of a binary neutron star system, GW170817. Almost simultaneously, a short gamma ray burst (GRB170817A) was detected by Fermi and INTEGRAL. This signal was localized to a relatively small region on the sky, triggering a massive follow-up with about 70 ground- and satellite-based telescopes in all bands of the electromagnetic spectrum. The timing and the morphology of both the gravitational-wave and electromagnetic signals have enabled a series of diverse studies leading to many ground-breaking results in astrophysics, fundamental physics and cosmology. In this seminar, we will review these recent discoveries, and we will discuss some of their implications.