Electromagnetic Counterparts of Gravitational Waves

Compact binary systems composed by neutron stars (NS) and black holes (BH) are one of the principal sources of gravitational waves (GW) in the terrestrial interferometers frequency range (10 Hz -1 kHz). While BH binary coalescences are not expected in general to be accompanied by any electromagnetic signal, detectable electromagnetic counterparts, such as Short Gamma-Ray Bursts (SGRB) and Kilonovae, could follow binary NS and NS-BH mergers.
The recent join GW and electromagnetic observation of a binary NS coalescence (GW170817) marked the down of multimessenger astronomy era that open a new way to explore the high energetic universe and test the fundamental physics under extreme conditions.
The coincident detection of gravitational and electromagnetic radiation is important because these messengers carry different and complementary informations: while from a GW detection it is possible to infer the masses and the spins of the binary progenitors, electromagnetic emission is essential to localize the source, thus enabling the host galaxy identification.
In this talk I will show how a joint detection of SGRB and GW from a NS-BH progenitor could be used to measure the neutron star radius and thus constrain the dense matter equation of state.
I will also provide a brief description of isotropic electromagnetic counterpart of compact binary coalescence such as Kilonova and Spindown powered transients.