Physical Properties, Baryon Content, and Evolution of the Lyα Forest: New Insights from High‐Resolution Observations at z ≲ 0.4

Abstract

We present a study of the Lyα forest at z ~13.2, with a column density distribution f(NHI)~N-βHI. For narrow (b 40 km s-1) Lyα absorbers (referred to as NLAs and BLAs, respectively). Both the NLAs and some BLAs probe the cool (T~104 K) photoionized IGM. The BLAs also probe the highly ionized gas of the warm-hot IGM (T~=105-106 K). The distribution of b has a more prominent high-velocity tail at z