Research | Astrophysics

Astrophysics of Galaxies and Cosmology

Luminous matter represents ~5% of the total matter of the Universe, the rest is called dark matter and its study is only possible thanks to indirect methods. One of the most effective methods, predicted by the theory of General Relativity, is "gravitational lensing". In the presence of a large mass, space-time curves and the path of light rays is no longer straight, with an effect similar to that of a lens. Galaxy clusters represent the cross-road between astrophysics and cosmology allowing us to study both light and dark matter. In fact, they are ideal laboratories in which to study the evolution of galaxies and they allow us to study the distribution of dark matter and verify its understanding, acting as gravitational lenses. The availability of ever more accurate data (e.g., JWST, Figure) is revolutionizing the knowledge in this field.

Black holes and exoplanets

The deflection of light from gravitational fields (gravitational lensing) has been long predicted by General Relativity. This effect assumes extreme proportions in the case of deflection from black holes, with the formation of infinite sequences of images surrounding the so-called shadow of the black hole. Microlensing, on the other hand, can be used to discover and study dark compact objects, such as white dwarfs, neutron stars, and black holes, but also to discover exoplanets. The huge variety of classes of planets discovered so far shows just how numerous the different formation mechanisms can be, while the search for habitable planets continues. Several space missions have been dedicated to these research topics, such as Gaia, TESS, JWST, and Roman, supported by numerous large and small terrestrial astronomical observatories.