Hi Andy,
I know of those plumes as I try to capture them in my H-alpha images:) Very interesting project you had there,will have to follow in your footsteps and have a go with the ALPY and my DIY 1200l/mm classical. One other target I have in mind,when Virgo gets a bit higher in the spring,M87, galaxy with a plume of material extending from a super massive black hole.
Regards
Alun