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

Understand

Throughout the epoch of reionization the most luminous Ly{\alpha} emitters are capable of ionizing their own local bubbles.

• The CR7 galaxy at $z \approx 6.6$ stands out for its combination of exceptionally bright Ly{\alpha} and HeII 1640 Angstrom 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 spectroscopy reveals a +160 km s$^{-1}$ velocity offset between the Ly{\alpha} and HeII line peaks while the spatial extent of the Ly{\alpha} emitting region is $\sim 16$ kpc.