We analyze the relationships between atomic , neutral hydrogen ( H i ) and star formation ( SF ) in the 12 low-mass SHIELD galaxies .
We compare high spectral ( \sim 0.82 km s ^ { -1 } ch ^ { -1 } ) and spatial resolution ( physical resolutions of 170 pc – 700 pc ) H i imaging from the VLA with H \alpha and far-ultraviolet imaging .
We quantify the degree of co-spatiality between star forming regions and regions of high H i column densities .
We calculate the global star formation efficiencies ( SFE , \Sigma _ { SFR } / \Sigma _ { H~ { } { \sc I } } ) , and examine the relationships among the SFE and H i mass , H i column density , and star formation rate ( SFR ) .
The systems are consuming their cold neutral gas on timescales of order a few Gyr .
While we derive an index for the Kennicutt-Schmidt relation of N \approx 0.68 \pm 0.04 for the SHIELD sample as a whole , the values of N vary considerably from system to system .
By supplementing SHIELD results with those from other surveys , we find that HI mass and UV-based SFR are strongly correlated over five orders of magnitude .
Identification of patterns within the SHIELD sample allows us to bin the galaxies into three general categories : 1 ) mainly co-spatial H i and SF regions , found in systems with highest peak H i column densities and highest total H i masses ; 2 ) moderately correlated H i and SF regions , found in systems with moderate H i column densities ; and 3 ) obvious offsets between H i and SF peaks , found in systems with the lowest total H i masses .
SF in these galaxies is dominated by stochasticity and random fluctuations in their ISM .