NGC 5128 Jet H-alpha just a few photons per hour

[Placidus]

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 (https://cdn.eso.org/images/screen/eso1221a.jpg) shot in H-alpha, OIII, and visual.

We took 20 hours over three nights (https://photos.smugmug.com/Category/Astrophotography-at-Placidus/i-7twnZzk/0/e7bffad4/X5/NGC%205128%20H-alpha%2019%20hrs-X5.jpg). 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! :D

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

[strongmanmike]

That's awesome you two :thumbsup:...how on Earth (or should I say galaxy?) does something like that occur :eyepop:...the Universe is an amazing place :)

Great project, stick with it, much better than another Eta Carina nebula :lol: :thumbsup:

Mike

[Retrograde]

This just gets better and better!

[Stevec35]

Amazing - certainly haven't seen the jet in that amount of detail before. Inspiring work!

Cheers

Steve

[Bassnut]

Stunning M&T (in a scientific sort of way), I havent see that jet so clearly before either :thumbsup::thumbsup:

[topheart]

Wow Wow Wow!
I also have never seen such an extension of the jet!
Eye opening!!
Thanks,
Tim

[Martin Pugh]

Very, very cool. Never seen that.

great job.

cheers
Martin

[gregbradley]

Amazing

The forces involved beggar
belief.

Greg

[multiweb]

:bowdown:

[RickS]

Love it, M&T :thumbsup:

[Placidus]

Slight mistake in the maths. With A/D gain of 1.5 e/count and QE for H-alpha a lowly 0.45 e/photon, that's 3.3 photons per count, or about 6.6 per hour. But we won't tell if you don't. ;)



Thanks so much, Mike. Aye, an amazing place.



Thanks Pete!



Hi, Steve. Now we know where to point, we could do a somewhat better job. The scope vignettes right up in the corner.



Hi, Fred ! Glad you like it too.

[Placidus]

Thanks, Tim. This has probably been our most fun project to date, partly because of what the jet represents, and partly because nothing much went catastrophically wrong!



Thanks Martin. For the extreme outermost part, it was nice that we had Suavi's image to compare with, or we'd think it might be just noise or dodgy flats.



This is it exactly, Greg! Makes one think of Blake's Tyger. What immortal Hand or Eye could fling that stuff right through the thick of an especially immense galaxy? And when the Stars threw down relativistic jets, what dread Hand, and what dread Feet? Keep your thumbs out of the way!



Hi, Marc! We are tickled. :)



Thanks Rick. Can't wait to have a crack at the OIII. Tonight is annoyingly clear, but the moon is blasting down.

[DJT]

That's an excellent image. The jet is incredible..

Well done!

[Peter Ward]

Very humbling to see that level of depth...I'd only gone 5 hours with the 16RC
And had my suspicions that the jet was massive....but having seen your splendid effort....aye carrumba !

Wonderful stuff. :thumbsup:

[marc4darkskies]

Very cool indeed M&T! Extremely envious of your dark skies and cloud free nights!

[cometcatcher]

Holy smoke! Looks a bit like it too. ;)

[Atmos]

It's spectacular the depth you've achieved! I would be most interested to see whether anything more would appear after another 20 hours :P

As a comparison, attached is ~4 hours taken under near full moon (no real difference between 2 & 4 hours due to moon and transparency) which has been given heavy noise reduction and stretched to all buggery. Helps give some appreciation with just how deep and faint some of that Ha is at the extreme top left. I've captured some of the brighter bits up there, albeit mottled from NR. You've captured the fainter stuff around that faint stuff!

[markas]

Amazing!

I seem to remember reading somewhere that the jets (note plural) are 'relativistic' - ie travelling at some large fraction of the speed of light. Has anyone picked up the other one????

If a massive black hole is responsible, you'd expect the second one to be heading in the opposite direction.

Mark

[astronobob]

:cool2: - - :cool2:

[Placidus]

Thanks David.



Many thanks, Peter. We're more and more thinking that the 20" PlaneWave is best for what we think of as faint detail, especially narrowband, like this, where it's photon bums on seats that counts. We're a bit ordinary at very bright detail, were dark sky is less of a prerequisite, and where a smaller scope with superb optics wins.



Thanks Marcus. The dark sky really helps. Mind you, Spring, Summer, and Autumn have been pretty much wall to wall cloud, but so far Winter has been very kind.



Thanks, Kevin.



Thanks, Colin. Your image captures the basic structure very well. It's good to know it's not just statistics or flats.



Hi, Mark. You are absolutely right that there should be two jets. Why can't we see the second one? The first thing to note is that the jet we can see curves over strongly. If the other one curves over, it might be curving behind the bright part of the galaxy. The second thing (and I'm on shaky ground here) is that I have the vaguest recollection that a relativistic jet coming substantially toward you looks much brighter than one going substantially away from you. Don't believe me on that. I need to go hunting. Mike.



:) :D :)

Best wishes,
Mike and Trish

[alpal]

Hi Mark,
I think the double jets - one each side - only show up properly in X-Ray light:

https://en.wikipedia.org/wiki/File:ESO_Centaurus_A_LABOCA.jpg

cheers
Allan

[traveller]

Wow, that's impressive!

[Placidus]

Thanks, Bo!

[Paul Haese]

Like I said on FB, that is cool. Or should I say hot. Well done.

[Placidus]

Cheers, Paul. Glad you like it. One century we must have a crack at it in OIII.

[Slawomir]

Fantastic result M&T :thumbsup:

Images like this one really inspire to explore new worlds where no man has gone before...

Love it!

[Placidus]

Thanks muchly, Suavi.

We're polishing up the warp drive. :)