Observations

Gaia reveals major galaxy collision that changed the Milky Way

Published on 20/08/2018

An international team of astronomers has discovered an ancient and dramatic head-on collision between the Milky Way and a smaller object, dubbed ‘the Sausage Galaxy’. The cosmic crash was a defining event in the early history of the Milky Way and reshaped the structure of our Galaxy, fashioning both the Galaxy’s inner bulge and its outer halo, as reported in a series of new papers.

Variable Universe

Variable stars, RR Lyrae, transients, supernovae, microlensing events.

High Redshift Galaxies

By studying high redshift galaxies, we can learn about the evolution of galaxies throughout the history of the Universe.

Gaia: a Stereoscopic Census of our Galaxy

Gaia is the ESA cornerstone mission set to revolutionise our understanding of the Milky Way.

Clusters of Galaxies

Clusters of galaxies are the largest objects in the Universe that are held together by their own gravity, and provide great tools for studying the processes that govern AGN feedback.

Accretion onto Compact Objects

A major area of research in X-ray astronomy is the accretion of matter on to black holes and neutron stars in the context of AGN and galactic X-ray binaries. Accretion is an energetic process and can give high luminosities.

Cosmic Reionisation

During the epoch of reionization the first stars and black holes in the Universe (re-) ionized the Intergalactic Medium. Studying the epoch of reionization will tell us about the first galaxies.

Cosmic Microwave Background

Observations of tiny fluctuations in the cosmic microwave background radiation give powerful constraints on cosmological parameters and theories of the early universe.

Gravitational Lensing

Gravitational lensing is used to determine the masses of lensing galaxies and clusters and to study more distant galaxies that can be magnified by a factor of more than 20.

Quasars and active galaxies

Quasars are the most luminous objects in the Universe and powered by accreting supermassive black holes in the centres of galaxies.