Galaxy clusters

Gravitational lensing

Galaxy clusters are also used for their strong gravitational potential as gravitational lenses to boost the reach of telescopes. The gravitational lensing provided by these clusters allows for the observation of distant galaxies during their early stages that would otherwise be unable to be detected. The gravitational distortion of space-time occurs near massive galaxy clusters and bends the path of photons to create a cosmic magnifying glass. This can be done with photons of any wavelength from the optical to the X-ray band. The latter is more difficult, because galaxy clusters emit a lot of X-rays. However, X-ray emission may still be detected when combining X-ray data to optical data. One particular case is the use of the Phoenix galaxy cluster to observe a dwarf galaxy in its early high energy stages of star formation.