Gravitational lensing reveals ionizing ultraviolet photons escaping from a distant galaxy

Understand

During the epoch of reionisation, neutral gas in the early Universe was ionized by hard ultraviolet radiation emitted by young stars in the first galaxies.

• To do so, ionizing ultraviolet photons must escape from the host galaxy.
• We present Hubble Space Telescope observations of the gravitationally lensed galaxy PSZ1-ARC G311.6602-18.4624, revealing bright, multiply-imaged ionizing photon escape from a compact star-forming region through a narrow channel in an optically thick gas.
• The gravitational lensing magnification shows how ionizing photons escape this galaxy, contributing to the re-ionization of the Universe.