We present deep , high velocity resolution ( \sim~ { } 1.6 km s ^ { -1 } ) Giant Meterwave Radio Telescope HI 21cm synthesis images for the faint ( M _ { B } \sim - 12.1 ) dwarf irregular galaxy GR8 .
We find that the velocity field of the galaxy shows a clear systematic large scale pattern , with a maximum amplitude \sim 10 km s ^ { -1 } .
Neither pure rotation , nor pure radial motion alone can fit the observed velocity field ; however a combination of radial and circular motions can provide a reasonable fit .
The most natural interpretation is that the neutral ISM , in addition to rotating about the center , is also expanding outwards , as a result of energy input from the ongoing star formation in the galaxy .
Support for this interpretation comes from the fact that the pressure in the HII regions in the galaxy is known to be substantially ( \sim 55 times ) more than the average pressure in the gas disk .
It is , however , also possible that the velocity field is the result of the gas swirling inwards , in which case GR8 could be in the process of formation via the merger of subgalactic clumps .