gravitationally lensed galaxy tagged posts

The Cosmic Horseshoe, as photographed by the Hubble Space Telescope. Credit: ESA/Hubble & NASA

Astronomers use observations of gravitationally lensed galaxy to measure properties of early universe. Although the universe started out with a bang it quickly evolved to a relatively cool, dark place. After a few hundred thousand years the lights came back on and scientists are still trying to figure out why. Astronomers know that reionization made the universe transparent by allowing light from distant galaxies to travel almost freely through the cosmos to reach us. However, astronomers don’t fully understand the escape rate of ionizing photons from early galaxies...