The nearby galaxy HIZSS003 was recently discovered during a blind HI survey of the zone of avoidance ( Henning et al .
2000 ) .
Follow up VLA as well as optical and near-IR imaging and spectroscopy ( Massey et al .
2003 ; Silva et al .
2005 ) confirm that it is a low metallicity dwarf irregular galaxy .
However there were two puzzling aspects of the observations , ( i ) current star formation , as traced by H \alpha emission , is confined to a small region at the edge of the VLA HI image and ( ii ) the metallicity of the older RGB stars is higher than that of the gas in HII region .
We present high spatial and velocity resolution Giant Meterwave Radio Telescope ( GMRT ) observations that resolve these puzzles by showing that HIZSS003 is actually a galaxy pair and that the HII region lies at the center of a much smaller companion galaxy ( HIZSS003B ) to the main galaxy ( HIZSS003A ) .
The HI emission from these two galaxies overlaps in projection , but can be separated in velocity space .
HIZSS003B has an HI mass of 2.6 \times 10 ^ { 6 } M _ { \odot } , and a highly disturbed velocity field .
Since the velocity field is disturbed , an accurate rotation curve can not be derived , however , the indicative dynamical mass is \sim 5 \times 10 ^ { 7 } M _ { \odot } .
For the bigger galaxy HIZSS003A we derive an HI mass of 1.4 \times 10 ^ { 7 } M _ { \odot } .
The velocity field of this galaxy is quite regular and from its rotation curve we derive a total dynamical mass of \sim 6.5 \times 10 ^ { 8 } M _ { \odot } .