I can't explain this because it's too weird. I saw the image processed at <a href="http://blog.galaxyzoo.org/2012/07/12/something-rich-and-strange-hubble-eyes-ngc-5972/" rel="nofollow">this article</a> and decided I wanted to try processing away some of those cosmic rays. Anyway, read that blog entry if you want to know more about it.

I spread the filters across the channels slightly to give it a more balanced look but [O III] is still represented by blue and Halpha is red.

The data is pretty noisy because it's all medium and narrowband imagery. Can't really be helped. Well, not without a bunch more orbits.

<a href="http://archive.stsci.edu/proposal_search.php?mission=hst&id=12525" rel="nofollow">Giant Ionized Clouds Around Local AGN - Obscuration and History (HST Proposal 12525)</a>

Red: WFC3/UVIS F763M + WFC3/UVIS F673N + WFC3/UVIS F621M Green: WFC3/UVIS F621M + ACS/WFC F505N Blue: ACS/WFC F505N