F. Fraternali on "Gaseous haloes: linking galaxies to the IGM"
Spiral galaxies have lots of gas around them. And the space between galaxies is not totally empty either: there is the inter-galactic medium (IGM).
The speaker presents very deep radio observations of NGC891 and, not surprisingly, finds gas t large distances from the plane. They find filaments and small counter-rotating clouds. In another case (NGC2403) they see infall of gas in the position-velocity-diagram.
They model their observations assuming hydrostatic equilibrium and the things that not not fit yet, may be resolved, when the interaction of the cold gas with the hot halo gas is included.
The IGM that was in the title, was however not mentioned very much.