HCG 16 is a prototypical case of and intermediate stage group in the evolutionary model of Verdes-Montegro et al. 2001. Its galaxies are in the process of losing their gas into the intra-group medium and there are numerous on-going processes, such as active nuclei, starburst events, a new group member, and enormous tidal features. This makes HCG 16 an ideal case study to assess which processes are likely those responsible for driving the evolution of compact groups from this stage to their final state where the galaxies are devoid of HI gas.

In this work we re-reduced archival VLA observations of the group, processing and analysing the data with the the latest tools and algorithms. This included the using the multi-scale CLEAN algorithm to image the data and the SlicerAstro package to separate galaxies from tidal features. We also constructed a 3D representation of the final HI data cube using the X3D framework.

As can be seen in the figure of this link, the HI content of the groups is highly disturbed, however, globally the group is not deficient in HI when compared to isolated AMIGA galaxies. The majority of the gas spread throughout the group appears to have originated from the pair HCG 16a and b, which are both highly HI-deficient. The 160 kpc long HI tail that extends to the South-East and connects NGC 848 to the core group, appears to be part of an even larger continuous structure (see below) which was probably formed when NGC 848 passed close by the core group and attracted loosely bound gas in the vicinity of HCG 16a and b.