antennae - more data

[Shiraz]

Hi

Apologies for a repro, but I got a few more hours of data on the antennae resulting in lower noise and enabling more saturation (maybe overdid this, but it's still nothing like as fluoro as some on the net). Seeing for the extra data was only average, so there was no increase in available detail.

The sky was around 20 mag/arcsec2 overall, so this is not very deep. Tried a heavy stretch which pretty much obliterated the core - it's really ugly, but shows some of the detail in the star streams.

images all cropped to fit. #1 software binned 2x2 to show context, #2 crop on core in full resolution and no compression, #3 messy heavy stretch at 2x2 bin to show star streams. Thanks for looking. Regards ray

[graham.hobart]

That's a lovely looking image Ray. Two of my favourite galaxies and a beautiful version.:thumbsup:
Graz

[strongmanmike]

Mate, that really is a sensational image of this pair Ray :thumbsup: certainly shows that seeing can be a blessing and the saturation is just right IMO (coming from a flurofile that is :P)

Mike

[gregbradley]

I agree with Mike that really is a sensational image. If I got that from the CDK17 I'd be stoked.

Terrific colour and detail and stars are lovely and tight and nice colours, a great background. But the star of the show is the galaxy itself which usually does not come up with that level of detail very often.

You're punching above your gear weight there.

Greg.

[atalas]

Top stuff!

[Astro_Bot]

Great stuff. :thumbsup:

[sjastro]

Great image Ray.

Steven

[Nicola]

Very nice image indeed!

[Shiraz]

thanks Graham - it is one of my favourites as well


thanks Mike - yep, its all about seeing :thumbsup:


really appreciate your comments Greg. I was very pleased with how it turned out in the end.

Thanks Louie


thanks for that


Thanks Steven. thanks also for your very clear explanations on the inflation thread.


hi Nicola - thank you.

[David Fitz-Henr]

That's a great image Ray, and nicely processed too! That's been taken with your new scope (250mm f/4 Newtonian), correct?

[madbadgalaxyman]

Blue knots at the end of one of the tidal tails are much more prominent than usually seen in other images.
These are very tough objects....so really good work on your part!

[RickS]

Great stuff, Ray! A nice improvement over the original which was already fantastic :)

[cazza132]

Beautiful work - love it! I'd love to be able to have a crack at some of these deep sky targets someday.

[Shiraz]

Thanks David - yes, this is the new 250f4 Newtonian. It's CF, which is so much more user friendly than the old steel scope was.


Thanks Robert. some interesting dynamics on display here.


Thanks very much Rick


Thanks Troy. yes, it's good fun when the seeing is OK and you can see some detail in the raw images.

Regards ray

[madbadgalaxyman]

G'day Ray,

From time to time, objects that are supposedly "Tidal Dwarf Galaxies" (= TDGs) get into the news, as investigators investigate the plausibility of small dwarf galaxies forming in the tidal tails of merging/interacting galaxies.

Obviously, as can be seen from your image and also in images of many other tidal tails, dwarf-galaxy-sized objects that are very rich in (very luminous) O and B stars, definitely do form within tidal tails, as there is (often, but not always) plenty of gas in the tails.

However, it is not likely that these small Tidal Dwarf Galaxies contain dark matter, and dark matter content is the necessary condition for the usual type of galaxy. (which is why a globular cluster is not a galaxy)
[[ for instance, the smallest known galaxies contain the merest smattering of 10s of thousands of stars, but each of these galaxies has a strong indication of the need for 100s of times as much matter in some unknown form, in order to keep the system gravitationally bound ]]

There has never been any rigorous proof that TDGs actually do exist, though this doesn't stop people from studying the galaxy-scale blue knots found in some tidal tails.

I personally do suspect that TDGs don't really exist, and that the blue knots in tidal tails should not be called galaxies
(like the search for the legendary four-leafed clover, and similar to the situation when you spend years searching the fields for blue-coloured roses, I suspect that searching for TDGs may not be a fruitful research area)

However, here are two references which give information about TDGs.
Both of them seem to be by people who know what they are talking about, but I have not assessed the information here in any detail:

http://arxiv.org/ftp/arxiv/papers/0907/0907.3831.pdf

http://www.scilogs.com/the-dark-matter-crisis/2013/03/07/are-there-two-types-of-dwarf-galaxies-in-the-universe/

Whatever the case, the knots in tidal tails are interesting and extremely challenging objects for astro-imagers.

cheers,
Robert

[David Fitz-Henr]

I thought so, the quality was just too high for anything other than a Newtonian ;) :P

[SkyViking]

What a beautiful Antennae image, really nicely processed and showing some impressive detail. I like the saturation too, it's certainly not overdone for my taste :thumbsup:

Ah yes, Newtonian power! :P:thumbsup:

[John Hothersall]

Detail like that is amazing.

John.

[E_ri_k]

Awesome Ray, great image:thumbsup: You have captured loads of detail in there!

Erik

[Shiraz]

thanks very much for the info Robert - have not yet read the refs, but will.


:lol:... actually, a design that has been around for over 300 years probably has something going for it and modern CCs have fixed the single major shortcoming. Running at around f4 sure keeps imaging time manageable.


Thanks for the feedback Rolf


thanks John - appreciated


Thanks Erik. thankfully, seeing was pretty good for part of the period.

[Bassnut]

Excellent Ray, the tails came out well, they are hard to bring up. Top detail and very smick colour balance. A pleasure to view.