Extreme-UV photons from high redshift galaxies

Soon after the Cosmic Dark Age, our universe went through a phase transition from neutral to ionized. Today, most of the matter between galaxies is ionized. It is believed that the extreme UV photons emitted by the first galaxies were responsible for the reionization of our universe. However, the nature of such galaxies and how those photons escape remain elusive. 

In this talk, I plan to report the discovery of extreme-UV photons from a high redshift galaxy. This has become possible because of the AstroSat UV Deep Field (AUDF) created based on observations carried out by the Ultraviolet Imaging Telescope on AstroSat.The detection of extreme UV photons from distant galaxies would open up a new window to constrain the shape of the ionizing spectrum and shed new light on the nature of reionization galaxies.