The micro-structure of the intergalactic medium I: the 21cm signature from dynamical minihaloes

Understand

A unified description is provided for the 21cm signatures arising from minihaloes against a bright background radio source and against the Cosmic Microwave Background (CMB), within the context of a dynamical collapsing cosmological spherical halo model.

• The equivalent width distribution of the resulting 21cm forest is computed for LCDM cosmologies, along with the brightness temperature differential relative to the CMB.
• The effects of an ambient Ly-alpha radiation field and heating of the IGM on the signatures are included.
• It is shown that the dynamical effects of heating substantially suppress absorption features in the 21cm forest with observed equivalent widths exceeding 0.15 kHz.