We use the photoionisation and dust radiative transfer code MOCASSIN to create a model of the dwarf irregular galaxy NGC 4449 .
The best-matching model reproduces the global optical emission line fluxes and the observed spectral energy distribution ( SED ) spanning wavelengths from the UV to sub-mm , and requires the bolometric luminosity of 6.25 \times 10 ^ { 9 } L _ { \odot } for the underlying stellar component , M _ { \mathrm { dust } } / M _ { \mathrm { gas } } of 1/680 and M _ { \mathrm { dust } } of 2.2 \times 10 ^ { 6 } M _ { \odot } .