We report the results of the spatial analysis of deep ROSAT HRI observations , optical imaging and spectroscopy , and high–resolution VLA H I and continuum imaging of NGC 1961 and NGC 2276 .
These spirals were selected as showing some previous evidence for interaction with a surrounding ( hot ) diffuse medium .

Our results favor most aspects of these galaxies as being shaped by gravitational interactions with companions , rather than the asymmetric pressure from motion through an external medium .
The old stars follow the asymmetric structures of young stars and ionized gas , which suggests a tidal origin for the lopsided appearance of these galaxies .
In NGC 2276 , the H I and star-forming regions are strongly concentrated along the western edge of the disk .
In this case , the ROSAT HRI detects the brightest star-forming regions as well as the diffuse disk emission , the most distant galaxy with such a detection .
An asymmetric ionization gradient in the H II regions suggests radial movement of gas , which might have occurred in either tidal or wind scenarios .
The X-ray emission from NGC 1961 is dominated by a point source near the nucleus of the galaxy but extended emission is seen out to a radius of \sim 0 \farcm 8 .

Previous studies of the enrichment of the intragroup medium in the NGC 2300 group indicates that stripping may be important in this system , but the density of the IGM is much too tenuous to effectively strip the gas from the galaxy .
However , we propose that gravitational interactions in the group environment may enhance stripping .
During a gravitational encounter the disk of the spiral galaxy may be warped , making ram pressure stripping more efficient than in a quiescent disk .