Star formation on LV dwarf galaxies

With this sample we confirm a strict correlation between the atomic gas surface density and the star formation rate surface density, which is vertically offset from the Kennicutt-Schmidt relation by a factor of 10-30, and significantly steeper than the classical N=1.4 of Kennicutt (1998ARA&A..36..189K). We further infer the molecular fraction in the sample of low surface brightness, predominantly dwarf galaxies by assuming that the star formation relationship with molecular gas observed for spiral galaxies also holds in these galaxies, finding a molecular-to-atomic gas mass fraction within the range of 5-15 per cent.

Comparison of the data to available models shows that a model in which the thermal pressure balances the vertical gravitational field captures better the shape of the {Sigma}_SFR_-{Sigma}_gas_ relationship. However, such models fail to reproduce the data completely, suggesting that thermal pressure plays an important role in the discs of dwarf galaxies.