The scattering of FRBs by the intergalactic medium: variations, strength and dependence on dispersion measures

Understand

The scattering of fast radio bursts (FRBs) by the intergalactic medium (IGM) is explored using cosmological hydrodynamical simulations.

• We confirm that the scattering by the clumpy IGM has significant line-of-sight variations.
• We demonstrate that the scattering by the IGM in the voids and walls of the cosmic web is weak, but it can be significantly enhanced by the gas in clusters and filaments.
• The observed non-monotonic dependence of the FRB widths on the dispersion measures (DM) cannot determine whether the IGM is an important scattering matter or not.