Evidence for a direct collapse black hole in the Lyman α source CR7

Throughout the epoch of reionization, the most luminous Lyα emitters are capable of ionizing their own local bubbles. The CR7 galaxy at z ≈ 6.6 stands out for its combination of exceptionally bright Lyα and He ii 1640 Å line emission but absence of metal lines. As a result CR7 may be the first viable candidate host of a young primordial starburst or direct collapse black hole. High-resolution spec...