We were inspired by Slawomir's wider field image of NGC 5128 in H-alpha, and of course also by the
2.2 metre ESO shot in H-alpha, OIII, and visual.
We took
20 hours over three nights. One sub was dubious due to thin cloud, leaving 19 hours. Last night was about 50% moon, and gave only a very marginal improvement in signal to noise ratio.
You can see 5128 itself clearly at bottom right. The relativistic jet from the central super-massive black hole is the faint feather-like or fern-like structure heading off toward top left, and arcing over at the top left end.
The structures we've shown match one to one with Suavi's, and also seem to match the ESO H-alpha structures.
This thing is
faint. In the calibrated but unstretched stack, the second-from last largeish clump in the jet is 24 counts per hour, against a background of 22 counts per hour. So the structure is two counts (or roughly 6 incoming photons) per hour over a half metre aperture. Forgive us if the image looks a bit gritty and the flat fielding seemingly a bit ho hum !
Despite these gripes and limitations, we do seem to see a lot more structure in H-alpha than in RGB.
The ESO shot is of course ridiculously sharper, but ours (as is Suavi's) is much deeper, showing the jet going about 25% further out!
The ESO shot shows that the very finest, sharpest structures in the jet are strongest in OIII. We're hoping to eventually have a go in OIII, but only once the moon is down.
Astrodon 3nM H-alpha filter. 19x1hr. Aspen CG16M -30C, 20" PlaneWave. MI-750 fork. GoodLook 64.
Best,
Mike and Trish