Galaxy clusters are currently the largest gravitationally bound structures in the universe, they are composed of hundreds to thousands of member galaxies and a hot, dense gas within. Clusters are held together by the graviational pull of dark matter. To read more about galaxy clusters, click here.
Gravitational lensing is a term that describes the effect of distortion due to matter warping the fabric of space. At LoCuSS, we observe lensing through galaxy clusters in order to accurately their internal structure. To read more about gravitational lensing, click here.
Dark matter is the invisible material that makes up the majority of the mass in the universe. When it was discovered that galaxies in clusters were moving too fast to be bound by the visible matter, dark matter was introduced to explain their stability. To read more about dark matter, click here.
Dark energy is the name given to missing energy required to explain the observed acceleration of the expansion of the universe. It accounts for 73% of the mass-energy of the universe. To read more about dark energy, click here.