  We investigate the star formation threshold in NGC 6822, a nearby Local Group
dwarf galaxy, on sub-kpc scales using high-resolution, wide-field, deep HI,
Halpha and optical data. In a study of the HI velocity profiles we identify a
cool and warm neutral component in the Interstellar Medium of NGC 6822. We show
that the velocity dispersion of the cool component (~4 km/s) when used with a
Toomre-Q criterion gives an optimal description of ongoing star formation in
NGC 6822, superior to that using the more conventional dispersion value of 6
km/s. However, a simple constant surface density criterion for star formation
gives an equally superior description. We also investigate the two-dimensional
distribution of Q and the star formation threshold and find that these results
also hold locally. The range in gas density in NGC 6822 is much larger than the
range in critical density, and we argue that the conditions for star formation
in NGC 6822 are fully driven by this density criterion. Star formation is
local, and in NGC 6822 global rotational or shear parameters are apparently not
important.
