Imprints of temperature fluctuations on the $z\sim5$ Lyman-$\alpha$ forest: a view from radiation-hydrodynamic simulations of reionization

Understand

Reionization leads to large spatial fluctuations in the intergalactic temperature that can persist well after its completion.

• We study the imprints of such fluctuations on the $z\sim5$ Ly$\alpha$ forest flux power spectrum using a set of radiation-hydrodynamic simulations that model different reionization scenarios.
• We find that large-scale coherent temperature fluctuations bring $\sim20-60\%$ extra power at $k\sim0.002$ s/km, with the largest enhancements in the models where reionization is extended or ends the latest.
• On smaller scales ($k\gtrsim0.1$ s/km), we find that temperature fluctuations suppress power by $\lesssim10\%$.