I can’t explain this because it’s too weird. I saw the image processed at this article 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.
Giant Ionized Clouds Around Local AGN - Obscuration and History (HST Proposal 12525)
Red: WFC3/UVIS F763M + WFC3/UVIS F673N + WFC3/UVIS F621M
Green: WFC3/UVIS F621M + ACS/WFC F505N
Blue: ACS/WFC F505N
North is NOT up. I’m not actually sure which way is up. Sorry about that.
Copyright information:
Hubble data is public domain, but I put a lot of work into combining it into beautiful color images. The minimal credit line should read: NASA / ESA / J. Schmidt
This work is licensed under a Creative Commons Attribution 3.0 Unported License.