On 2016-08-05 the 1.2 mag brightening of an otherwise quiet stellar source triggered the Gaia16aye Gaia Science Alert, nicknamed Ayers Rock (19:40:01.13 +30:07:53.4, J2000). The previous 22 Gaia detections of the source (starting from 2014-10-30) show no variability greater than 0.05m RMS. The initial spectrophotometric observations did not clarify the nature of the
…→ Read More: Gaia16aye: the first binary microlensing event ever discovered towards the Galactic Plane
The epoch of reionization marks a major phase transition of the Universe, during which the intergalactic space became transparent to UV photons. Determining when this occurred, the physical processes involved and the sources of ionizing radiation represents one of the major goals in observational cosmology. This topic inevitably requires the investigation of distant
…→ Read More: Characterizing faint galaxies at the epoch of reionization
Galaxy clusters are the largest and most recently formed cosmic structures in the universe, of which their content is expected to reflect the overall matter composition. They are dominated by the elusive substance that we call dark matter, but they also contain a smaller fraction of matter in the form of gas and stars. Although
…→ Read More: The mass distribution of galaxy clusters: a remarkable agreement between theory and observations
Dark matter (DM) is one of the pillars of our cosmological understanding yet its nature is still elusive. It makes up about 85% of the Universe’ matter but its presence has been revealed only through gravity. The most interesting probes of its presence and nature is the merger of two clusters (or groups) of galaxies.
…→ Read More: The nature of dark matter unveiled by cosmic collisions: the bullet group
Most massive galaxies in the Universe host a giant black hole (BH) at their center, with mass ranging from one-million to one-billion solar masses. The formation of stars in a galaxy and the growth of its central supermassive BH are often thought to be correlated processes, which is conventionally referred to as galaxy-BH co-evolution. Active
…→ Read More: ALMA reveals an extremely compact starburst around a hidden black hole in the early Universe.