We have conducted a study with the VLA , the DRAO ST , and the FUSE satellite to search for the intra-group medium in two loose groups of galaxies : GH 144 and GH 158 .
The VLA observations provide a census of the dense H i content of these groups in the form of individual galaxies and free-floating H i clouds as traced by the 21-cm H i line , while the FUSE observations trace the diffuse neutral and hot ionized gas that may fill the intra-group medium , populate the halos of individual galaxies , or reside in a skin around denser , neutral clouds .
While nothing was detected in GH 158 , in GH 144 we detected two previously unknown H i-rich low-surface brightness group galaxies .
In addition , Ly- \alpha , Ly- \beta , C iii and N v were detected towards GH 144 .
Using this suite of data , we were able to place limits on the mass of various portions of this group .
If virialized , GH 144 has a mass of 2 \times 10 ^ { 12 } M _ { \odot } .
Of that mass , 8 % lies in the individual catalogued galaxies , and no more than that same fraction again could lie in the dense , neutral medium as constrained by our VLA observations .
The absorption lines imply a diffuse gas with a volume density greater than 10 ^ { -5.2 } cm ^ { -3 } from a layer less than 22 kpc thick , assuming a metallicity of 0.4 Z _ { \odot } .
While the extent of this gas is uncertain , it seems unlikely that this diffuse gas contributes a significant fraction of the group mass .
Given the depth of the absorbing material , and its separation from the nearest galaxies , it seems most likely that it originates from a small clump in the intra-group medium ; perhaps an ionized high-velocity cloud , but it may be associated with one of our new H i detections .
This was an ambitious first attempt to search for the IGM in emission and absorption , and while it was only partially successful we show what is possible and what more is needed for its success .