Centaurus A - Progress!

[pvelez]

I am pretty chuffed with this image. I've established that I have some really good data from my remote set up at Coona and have been let down my processing skills. I think this is an improvement.

Apart from more data, I have managed to get Cosmetic Correction working for me in PI - the readout artefacts I had in earlier images are conspicuous by their absence.

I still have a way to go with PI - Mr Sidonio will tell me I have been too harsh with the Deconvolution and the colour palette might be a bit warm for some. That said, it is good to take everything through PI with only Maxim for imaging/guiding.

The link to my PBase site is here - http://www.pbase.com/equitius/image/155984606

The blurb for the image on my site is as follows:

Centaurus A, also known as NGC 5128 is a galaxy in the constellation Centaurus. It is relatively close to us although there is some dispute about its actual distance. Estimates range from 10 - 16 million light years.

It was discovered by James Dunlop from his observatory in Parramatta, Sydney in 1826. It is the 5th brightest galaxy in the sky so its an ideal target for astrophotography from the southern hemisphere.

It has a few interesting features. The prominent dust lane, coffee coloured in my image, indicates that we are viewing the galaxy edge-on.

This is a starburst galaxy, likely caused by an interaction with a galactic neighbour. The red/purple areas are regions of active star formation. There are many young, hot stars here that live by the maxim "Live fast, die young". The region is ripe for supernovae.

There is also a supermassive black hole lurking at the centre of this galaxy. It weighs in at around 55 million times the mass of our Sun. Matter is collected around the black hole in an accretion disk which emits brightly at all wavelengths. At the poles of this monster, matter is ejected at near light speeds. These relativistic jets are bright at both UV and radio wavelengths. Using a radio telescope, it is hard not to detect these jets.

Taken with an SBIG STX16803 on a Planewave CDK12.5. All subs were 5 minutes for a total of 5 hours Luminence and 3 hours of each of R, G and B. RGB subs were binned x2 while L was unbinned.5 hours of Luminence and 3 hours of each of R, G and B. All subs are 5 minutes with L unbinned and RGB binned x2. Imaged with STX16803 on a Planewave CDK12.5.

Comments and tips all welcome

Pete

[Peter Ward]

Not sure the halo is quite that yellow :question:.....but hey, I'm quibbling about looking at an S-Class or 7-Series at best. :)

Very impressive smoothness & resolution.

Nice one:thumbsup::thumbsup:

[alpal]

Hi Pete,
That's looking great.
I think I can see the jet.
I would done some selective sharpening on the brightest parts of the galaxy
using feathered & blurred masks in Photoshop.

cheers
Allan

[alocky]

I'm having a great time cruising through that image looking at the background galaxies. The star colours look natural, and at normal viewing scale the decon doesn't look too intrusive at all.
Very nice!
Andrew.

[PRejto]

Hi Pete,

That is becoming a very nice image! Must be nice to finally have everything going to plan!

Peter

PS Nice to know my ex counter weight is contributing to those nice round stars!

[strongmanmike]

That's a very fine image of Cen A Pete with great scale :thumbsup: looks quite smooth :question: maybe a bit too smooth? but then maybe not..did you use noise reduction? No biggy :)

Yes, sorry, the decon is noticeable in the galaxy lane region at the full res there..but when shrunk to about 50% in my browser it looks great :thumbsup:

Great background details to pan around, top effort :)

Mike

[David Fitz-Henr]

That's a great image Pete, with great scale as Mike says and nice tight stars too at that scale :thumbsup:
I'd also agree with Peter that the halo looks a bit yellow; it appears to me that the colour balance is too heavy in green which also results in many stars having a cyan / green halo, as well as a slight lack of contrast between some of the lighter dust lanes and galactic halo as well.

[DaveNZ]

Great Image Pete. Well done.

Maybe a tad over saturated but I like like plenty of colour ;-)

[Elio]

Great image of a spectacular subject, very well done :thumbsup:

[pvelez]

Thanks Peter - the STX16803 works a treat.

I agree its a bit yellow - at the AAIP conference last year I realised I side with the "more colour" camp and it shows in this image. I might dial it back a bit.



Thanks Allan - I've just learnt how to sharpen with PI using wavelets. Up to now all my images have been a bit soft. Will play with it a bit more on this image I think.



I was surprised there were so many fuzzes lurking in the background - not as many as Rolf's megamega project but still plenty to play with



Yep - its all rock solid Peter. Thanks again for the counterweight.



Cheers Mike.

I used ACDNR on the RGB but not on the Lum. Dark skies make such a difference!

I had you in my ear as I did the Decon - believe me, this is dialled back. But now I have a handle on wavelets, I can go easier on the Decon next time.



Thanks David - colour is so touchy. Its at my learning edge.



Thanks Dave



Cheers

Pete

[alpal]

Yes Pete,
I used such techniques here:
https://www.flickr.com/photos/24719437@N03/8796041386/in/photostream\

I also saved the stacked file in DSS as 32 bits & stretched in 32 bits with NASA's FITS Liberator.
I use Photoshop & Fitswork4 for processing in 16 bits.
I like the way Photoshop allows you to use masks & just work on the areas of choice.
e.g. the brightest areas will have high signal to noise ratio
& more can be pulled out of them.

[Shiraz]

Beaut image Pete - looks great . You clearly have sorted out the processing problems. Regards Ray

[astronobob]

Fab result Pete :cool2: real nice work on the stars also, in particular the larger with spikes. Great depth throughout the field, awesome :thumbsup:
I also wonder if the dust lanes and galaxy central action parts may afford a smidge more sharpening/contrast, tho, not sure what the 'perfect' image is surpose to look like :question: Only my opinion as I gaze apon the overall appearance with hobbyist level eyes, I definately cant claim any educated critique as I dont have a speacialist astro-imagers mind :thumbsup:
It is a 'way better' image than I could ever hope for, a very well done piece of work :thumbsup:

[gregbradley]

I can see why you are happy with this one. Very nice. You got the jet as well. Plus some of the dust blobs higher up.

Yellow is off as is the magenta/purple star forming region which should be blue. The yellow is too strong and the yellow stars look like a greeny yellow so colour balance needs adjustment. Easy to do and it would make a great image even nicer.

Greg.

[marco]

I agree with others about the overall color calibration even though your renditions is surely eye catching. This is a great Centaurus A in my opinion, if you can tune up a bit the color balance it will be outstanding :thumbsup:
Regards
Marco

[RickS]

Looks great, Pete! I agree the colour balance is a little off but that should be easy to fix.

Cheers,
Rick.

[pvelez]

Thanks everyone for the comments

Here is a version with the saturation dropped. I've also sharpened the dust cloud a bit with ATWT - though the Decon is more apparent with this one - sorry Mike :D

Pete

[strongmanmike]

:lol: Mike the decon policeman :P

It looks ok presented at this file size ;)

[Paul Haese]

I took the image and did an auto colour and selective sharpen to the dust lane and it had quite an impact to the overall look to the data Pete. The halo looked better with auto colour and the stars looked correct.

Looks like great data anyway and very smooth background. Well done.