Exploring Gravitationally-Lensed $z\gtrsim6$ X-ray AGN Behind the RELICS clusters

Understand

Although observations of high-redshift quasars demonstrate that many supermassive black holes (BHs) reached large masses within one billion years after the Big Bang, the origin of the first BHs is still a mystery.

• A promising way to constrain the origin of the first BHs is to explore the average properties of $z\gtrsim6$ BHs.
• However, typical BHs remain hidden from X-ray surveys, which is due to their relatively faint nature and the limited sensitivity of X-ray telescopes.
• Gravitational lensing provides an attractive way to study this unique galaxy population as it magnifies the faint light from these high-redshift galaxies.