Theoretical determination of HI vertical scale heights in the dwarf
  galaxies: DDO 154, HoII, IC2574 & NGC2366
  In this paper, we model dwarf galaxies as a two-component system of
gravitationally coupled stars and atomic hydrogen gas in the external force
field of a pseudo-isothermal dark matter halo, and numerically obtain the
radial distribution of {H\,{\sc i}} vertical scale heights. This is done for a
group of four dwarf galaxies (DDO\,154, Ho\,II, IC\,2574 and NGC\,2366) for
which most necessary input parameters are available from observations. The
formulation of the equations takes into account the rising rotation curves
generally observed in dwarf galaxies. The inclusion of self-gravity of the gas
into the model at par with that of the stars results in scale heights that are
smaller than what was obtained by previous authors. This is important as the
gas scale height is often used for deriving other physical quantities. The
inclusion of gas self-gravity is particularly relevant in the case of dwarf
galaxies where the gas cannot be considered a minor perturbation to the mass
distribution of the stars. We find that three out of four galaxies studied show
a flaring of their {H\,{\sc i}} disks with increasing radius, by a factor of a
few within several disk scale lengths. The fourth galaxy has a thick {H\,{\sc
i}} disk throughout. This arises as a result of the gas velocity dispersion
remaining constant or decreasing only slightly while the disk mass distribution
declines exponentially as a function of radius.
