As part of an effort to enlarge the number of well-studied Magellanic-type galaxies , we obtained broadband optical imaging and neutral hydrogen radio synthesis observations of the dwarf irregular galaxy ESO 364-G029 .
The optical morphology characteristically shows a bar-like main body with a one-sided spiral arm , an approximately exponential light distribution , and offset photometric and kinematic centers .
The H i distribution is mildly asymmetric and , although slightly offset from the photometric center , roughly follows the optical brightness distribution , extending to over 1.2 Holmberg radii ( where \mu _ { B } = 26.5 mag arcsec ^ { -2 } ) .
In particular , the highest H i column densities closely follow the bar , one-arm spiral , and a third optical extension .
The rotation is solid-body in the inner parts but flattens outside of the optical extent .
The total H i flux F _ { H \textsc { i } } = 23.1 \pm 1.2 Jy km s ^ { -1 } , yielding a total H i mass M _ { H \textsc { i } } = ( 6.4 \pm 1.7 ) \times 10 ^ { 8 } { M } _ { \odot } ( for a distance D = 10.8 \pm 1.4 Mpc ) and a total H i mass-to-blue-luminosity ratio M _ { H \textsc { i } } / L _ { B } = ( 0.96 \pm 0.14 ) { M } _ { \odot } / { L } _ { B, \odot } ( distance independent ) .
The H i data suggest a very complex small-scale H i structure , with evidence of large shells and/or holes , but deeper observations are required for a detailed study .
Follow-up observations are also desirable for a proper comparison with the Large Magellanic Cloud , where despite an optical morphology very similar to ESO 364-G029 the H i bears little resemblance to the optical .