Dust in the IGM: pro and contra

Abstract

Observations of dust grains in the intergalactic medium (IGM) allow us to study an important aspect in the evolution of galaxies. Although it existence had been previously speculated upon, direct evidence of the presence of dust in the intergalactic space has only been available recently. We discuss various issues regarding the presence of dust in the IGM—its sources, transport mechanisms from galaxies into the IGM, its effect on reddening and on cosmological studies.