NGC1365 - Cosmic Maelstrom

[jase]

Hi All,

I’m pleased to present my rendition of the Fornax Galaxy Group member - NGC1365 (http://www.cosmicphotos.com/gallery/image.php?fld_image_id=118&fld_album_id=12).

NGC1365 is a giant barred spiral galaxy located in the constellation Fornax and a member of the Fornax Cluster of Galaxies. Many spiral galaxies have bars across their center, however few are so prominent as the one present in NGC1365. The location of young blue star clusters and pink HII regions in the dramatic spiral arms indicate a strong rotating density as they twirl towards the galaxy’s nucleus. The bright yellow nucleus is likely to contain a massive black hole. Astronomers believe the gravity field of NGC1365's bar plays a crucial role in the galaxy's evolution, funneling gas and dust into the central star forming regions and ultimately feeding material into its massive black hole. NGC1365 is approximately 60 million light-years distant.

About the image;
Image is a LLRGB composite totaling 5 hours (L;120min;R:60min;G:60min;B:60min). Lum bin 1x1 @ 15min subs and RGB 2x2 bin @ 10 min subs. Image data was aquired using a RCOS 12.5”as part of the www.global-rent-a-scope.com (http://www.global-rent-a-scope.com) network. This galaxy requires a reasonably long focal length to bring out the subtle details. At ~2900mm, I think this clearly shows what is achievable. This is the first time I’ve not had to deal with gradients from this instrument – big relief. Don’t really enjoy working with gradients – who does? I was very surprised by the quality of the raw subs. I even managed to use the true Astrodon colour ratios of 1:1:1 for change <shock/horror!> (actually I used 1:1:1.2 to counteract blue extinction factor). To be honest, I was expecting vibrant colours, but obviously this is not characteristic of this galaxy. Sure, I could have push the chrominance harder to achieve this, but wanted to keep a natural/realistic feel. The image presented is a crop of a much larger field/image.

Image processing;
Rather simple processing on this object (as expected due to the quality of the subs – a pleasure to work with). All subs – dark/flat/bias calibrated, hot and dead pixel removal performed in MaximDL. All subs registered in Registar, then combined back in MaximDL using Sigma-reject. Chrominance combined in MaximDL and pushed out as a stretched tiff for processing in PS. Luminance ran through two iterations of deconvolution in CCDSharp, saved as tiff for processing in PS. In PS, stretched the chrominance using the Shadow/Highlights tool, layered the luminance. Luminance blend was set as 50% opacity so I could still manage colour flows. Image flattened, luminance layer applied again at 100% opacity, colours re-balanced. Highpass and noise reduction mask applied. Final colour balance tweaks, before adjusting levels. The only task I did differently that isn’t mentioned above was re-layer the chrominance with the blend option as colour. I then stretch the layer using curves to bring back some subtle colour tones that appeared to get lost in the LLRGB combination.

Well… I could not simply let the 1,000th post go by without delivering a “respectable” image to the IIS imaging community. ;) So I hope you enjoy the image as much as I did processing it! :D Thanks for looking.

Clear skies, new moon – opportunities await.
Cheers

[DeanoNZL]

Once again, a lovely image Jase.
Welcome to the "1000" club.

[citivolus]

Very nice. I've gotta get me one of them scopes :)

Eric

[gbeal]

Wow Jase, a stunner. I shot this as well recently, but it certainly didn't look like that.
Spectacular shot.
Gary

[iceman]

Wow that's a remarkable image, Jase. Incredible resolution and depth, and so many background faint fuzzies!

Congrats on your 1000th post, too. I've really enjoyed all your contributions and your sharing of knowledge is greatly appreciated.

[Alchemy]

dead set incredible ..... youre the king of processing jase.:thumbsup:

[acropolite]

Beautiful image Jase, I'm most impressed by the quantity of background galaxies, makes one feel rather insignificant..:thumbsup:

[Dennis]

Wow – a truly magical, awe inspiring image Jase. I’m still looking at it on my 2nd cup of tea this morning. Time for a 3rd! Hmm, gonna have to get me a 2400x1800 monitor; my 1600x1200 didn’t do it justice!

Cheers

Dennis

[jase]

Thanks Adrian! Pleased you like it.:D



Cheers Eric.:) They are pricey, but the output quality speaks for itself. If you can't afford one, renting one is a good alternative.



Thanks Gary. :thumbsup: Actually it was your NGC1365 post that gave me such inspiration to capture the field. You portrayed the object very well.



Thanks Mike. You're the catalyst amongst us. You've built a noteworthy community in which I'm pleased to be a part of. It is with great pleasure that I can share my knowledge with like minded people. Thanks again.:thumbsup:



Cheers Alchemy. Not sure about the king. ;) Seriously, I'm still learning. The trick is to push boundaries and maximise the data's potential.



Thanks Phil. Fully agree. While processing this image I got a ghostly sense of being a blip in time. Rather weird. Compared to cosmic time, we live for only a few minutes. Make the most of it.;)



Cheers Dennis. Pleased to provide viewing pleasure while you enjoy your morning cuppa.;)

=================

Here's the full frame image (http://www.cosmicphotos.com/reprocessed/NGC1365-FINALrevB.jpg) reduced by 50%. I really enjoy the bright star to the upper left as it gives your eye a reference point to wander the image. Took a while to work out the best composition for this object, but I think I hit the right mark for aesthetics. I had not performed any colour noise reduction on this so its not quite the final full frame version (but thought I'd post it anyway).

Enjoy!:D

[JohnG]

Another fantastic image Jase, I enjoy the way you are drawn into the scene and the amount of Galaxies that are deep in the background.

Cheers :thumbsup:

[Garyh]

fantastic Jase..like always very well processed and so detailed. The 5 hours of data collection has defiantly paid off!
Beautiful!
cheers Gary

[RB]

Nothing short of Perfection, to my eyes Jase, awesome work !!!
I love reading and viewing your posts/images and your processing write-ups.

Congrats on you 1000th and always look forward to your next one.
Keep up the great work.


Hope your using the good Twinings Speciality blend Dennis, well worth it for this image.... :thumbsup:

[seeker372011]

man o man-that's got to be one of the best images I can recall having ever seen of the Great Barred Spiral
that's a worthy 1000 post all right

[Ric]

What a beauty Jase, you have captured some fantastic details as well as being so sharp and clear. The background galaxies almost give it a 3D feel as well.

A very impressive image.

[Dr Nick]

Beautiful image, incredible detail and nice colours! 10/10 ;)

[jase]

Thanks JohnG. :) I selectively processed the background galaxies to bring them out subtly. Use of a heavy noise reduction causes significant detail lost in them.



Cheers Gary.:thumbsup: I was hoping for more data on the luminance, but 2 hours seemed to be ok. I could stretch the luminance data reasonably hard without introducing much noise. Perhaps a few more hours would have provided greater detail in the spiral arms. Thanks again.



Appreciate the kind words RB.:thumbsup:



Thanks Narayan:)



Cheers Ric. Pleased you like it!:D



Thanks Dr. Nick.:)

[h0ughy]

Jase - simply stunning. I do have one question though, since its not your gear, it looks like AMP glow to the upper left of the image - or was it near something bright? Mate if I could just manage a 10th of what you do I would be a happy man!

[2020BC]

Wonderful pic, Jase.

[jase]

Thanks Houghy. AstroCCD cameras don't have amp glow. The circuitry is significantly different to a regular DSLR. Though, there are still some similarities such as read out noise. The glow you see in the upper left is a bright star. If you check out my second post, you'll see the link to the full frame version. Here it is again (http://www.cosmicphotos.com/reprocessed/NGC1365-FINALrevB.jpg). Thanks for your comments.:)



Thanks Bill. Pleased you like it.:thumbsup:

[marc4darkskies]

Beautiful image Jase - as always!! :thumbsup: Any reason you keep the sky background so light? Bit of colour noise in there as well (?)

Congrats on your 1000th post too! At the rate I'm going the sun will be a white dwarf by the time I hit the submit buttom that many times. My STL is in rehab too - which doesn't help! :sadeyes:

Cheers, Marcus

[Bassnut]

Very nice , a pleasure to view, dust lane detail is esquisite, as expected, and tastefull colour balance. Inspirational.

[Kal]

Awesome pic Jase. I've just sat here for about 10 minutes staring at it. It truly is something to marvel at and enjoy :thumbsup:

[Tamtarn]

Very much the same comments as everyone else Jase ......... A truly wonderful image, very subtle processing revealing so much detail.

Your images are always worth waiting for and although we don't always understand your technical details on processing, we have picked up bits and pieces which have helped us in our progression. So thanks for sharing your expertise.

[jase]

Opps, missed these replies :doh:



Hi Marcus,
Thanks mate. Yes, there is quite a lot of whitespace to the left of the histogram. I didn't want to raise the blackpoint too much on this image as I found I lost many background galaxies. I could have masked them again to selectively process the background. There is still some colour noise present. I haven't finished on the image as yet. I'm thinking of acquiring some Ha data and subtracting the red channel from it to see what will change in the RGB process. Not entirely sure. Too many options/permutations to think of - imaging is only limited to the astrophotographer's imagination. Thanks again for your comments.



Cheers Fred. Pleased you like it (inspirational eh?;)). :thumbsup:



Thanks Andrew. :) It helps to revisit images with fresh eyes. Having gone back to it, I can see some minor anomalies which I'll process out when I get a moment.



Thanks for the kind words Barb and David. It is a pleasure to assist you and others so they can develop their processing skills/knowledge of imaging set ups/techniques. Once I stop learning, I'll be quitting.:lol: Thanks again for your comments.:thumbsup:

Cheers everyone :D

[strongmanmike]

Lovely image Jase :thumbsup: Some good detail there for sure!

There is less of that salt and pepper colour noise that plagued your previous images with Brad's setup, and while it isn't bad there appears to be a slight red gradient..?

Overall a great vista

Interesting to compare your image with an image I did with the inferior optics of a 12" SCT at 1500mm FL (poor guiding though, so had to work on the eggiest stars :(). The RC is an order of magnitude (or two?) better for sure!

http://www.pbase.com/strongmanmike2002/image/55269925/original

Mike

[ballaratdragons]

Crikeys Jase,

the largest res image is so sharp!!! Can just about see roads on the planets in the solar systems! :thumbsup:

But seriously, that is a nice image. Very clear and highly detailed. :thumbsup:

[jase]

Cheers Mike:thumbsup:. Have to say you're rendition is actually quite good considering the optics and all. As I mentioned in the original post of this image, I was actually surprised by the lack of noise and gradients in the raw data. Some noise still exists in the output presented as I've yet to get around to cleaning it up. I'm going to reprocess the image once I've acquired more luminance data. I really think there is more to this galaxy given ample exposure time. The nucleus is rather bright so its an interesting object to process. Thanks again for your comments. :)



Thanks Ken. Quality optics and shooting the luminance when the object is high is the key to sharpness. Once you've got reasonable data, its easier to produce a great image through processing. Thanks mate.:)

[danielsun]

Wow !! That's incredible Jase. Your images always blow me away!! :eyepop:
I can't believe how crisp and the detail of the barred ends spiralling into the centre.
Truly amazing!!

[jase]

Thanks Daniel. I've since reprocessed this image using a few other techniques, but its still sitting on my hard drive. Its not complete yet - need to perform the high pass mask. I'll upload it when its done. It is an improvement over this one, which is hindered by a dust mote, colour noise and down-toned colours. Thanks for checking it out:thumbsup:

[jase]

Greetings all,

Sorry to bring back this historic thread, but I thought I’d provide a quick update.

Having reworked the original NGC1365 image a few times over, I was still not satisfied with the result. Simply, insufficient data was to blame. The break through came when Fred (Bassnut) graciously provided some additional luminance data from his recent NGC1365 post. Despite the focal length differences, Fred’s 90 minutes of luminance data once up-scaled was quite smooth, complementing my original 120 minutes worth. I proceeded to blend this using lighten and duplicated the original layer to maintain details as an overlay blend. As Fred’s data was up scaled, twisted and twirled to match the original luminance, the stars went weird shapes and sizes. To ensure consistency with the surrounding frame, I used a mask to bring back the stars in the original image.

I’m now satisfied with the resulting image. Other than collecting copious amounts more data I don’t believe I can get much more from it. The final image can be seen HERE (http://www.cosmicphotos.com/gallery/image.php?fld_image_id=118&fld_album_id=12) or from the link on the original post.

Big shout out to Fred.:thumbsup: Thanks for allowing me to use your raw luminance data to finally complete this mission. Much appreciated.

Cheers

[sailormoon]

Wow that is one great looking spiral!