Speaker
Description
The reconstruction of the images of the supermassive objects at the centres of the M87 and Milky Way galaxies show two objects characterized by a central depression in luminosity (the so-called shadow) and a ring-shaped light structure around them. Both properties are closely linked to the emission intensity profile of the accretion disk and to the structure of spacetime. In addition, the detection of gravitational waves has made possible to study compact objects during the merger of binary systems of -mainly- black holes in order to test the Kerr family of solutions. In this talk, I will explain, on the one hand, the spacetime effects that influence the image obtained and how it may be used in the future to discern the existence of objects beyond the Kerr paradigm. Finally, I will also present the correspondence that exists between the shadow images and the spectrum of quasinormal modes of gravitational waves when such objects are perturbed. This is expected to play a fundamental role for the future multi-messenger astronomy of ultracompact objects.