  The baryonic Tully-Fisher relation is an important observational constraint
on cosmological and galactic models. However, it is critical to keep in mind
that in observations only stars, molecular, and atomic gas are counted, while
the contribution of the ionized gas is almost universally missed. The ionized
gas is, however, expected to be present in the gaseous disks of dwarf galaxies
simply because they are exposed to the cosmic ionizing background and to the
stellar radiation that manages to escape from the central regions of the
galactic disks into their outer layers. Such an expectation is, indeed, born
out both by cosmological numerical simulations and by simple analytical models.
