Lyman Alpha Emitting Galaxies as a Probe of Reionization

Understand

The Epoch of Reionization (EoR) represents a milestone in the evolution of our Universe.

• Star-forming galaxies that existed during the EoR likely emitted a significant fraction (~5-40%) of their bolometric luminosity as Lyman Alpha (Lya) line emission.
• However, neutral intergalactic gas that existed during the EoR was opaque to Lya emission that escaped from galaxies during this epoch, which makes it difficult to observe.
• The neutral intergalactic medium (IGM) may thus reveal itself by suppressing the Lya flux from background galaxies.