The Antenna Galaxy

[gregbradley]

This odd pair of colliding galaxies has its trademark 2 long tidal streams of stars. I have always intended to image this one but finally got an image of it.

I took this one over 2 nights and it was about 3 weeks ago now.

Planewave CDK17, Proline 16803, Paramount ME

LRGB 160 30 30 30.

I also got some Microline 8300 data on this as well which I may add later.

http://upload.pbase.com/gregbradley/image/135726600/large regular

http://upload.pbase.com/gregbradley/image/135726600/original large

Greg.

[jjjnettie]

Great image Greg. All those wee galaxies too!

[atalas]

Sweet shot Greg....you've got to get that CDK to your dark site!

[peter_4059]

Nice going Greg. Love the detail and colour in the galaxies.

[h0ughy]

you seemed to be well tuned in on this one ;) lovely image

[John Hothersall]

These are great galaxies engaging in a cosmic dance. Arms quite extensive.

John.

[ballaratdragons]

Nicely done Greg.

I love it when people capture the faint tail streams. I've never been able to.

Also a lovely galaxy cluster of very small very faint Galaxies at the edge of FOV at 7 o'clock :thumbsup:

[ChrisM]

Greg, another great shot. It certainly resonates with me!

Chris

[Paul Haese]

Lovely image Greg. Love the colour.

[Ross G]

An amazing photo Greg.

Thanks.


Ross.

[Gem]

Wow! Amazing what amateurs can do today! :eyepop:

[multiweb]

Nice one Greg. That's a really tough one at best. :thumbsup:

[madbadgalaxyman]

The small bluish knots at the end of one of the tidal tails are a really tough target. They are pretty obvious on some of the old blue-sensitive photographic plates, but not so obvious in CCD images.

The best I have seen them in an amateur image is probably at Rob Gendler's website.

The case for these knots being bona fide areas of very hot & very luminous OB stars is greatly strengthened when we consider the GALEX (Far Ultraviolet plus Near Ultraviolet) image of NGC4038/9 :

96196

Blue in this image codes for Far-ultraviolet light.
(see the GALEX "how to" in the Observational Astronomy forum )
Note how there are star forming knots all along the tails!
They must be very faint indeed in visible light.....

Incidentally, the knots correspond well with those areas where the HI (cold neutral atomic hydrogen) in the two tidal tails is most dense....so there appear to be adequate raw materials (gas) to produce star formation in the tails.

[renormalised]

Nice shot, Greg. I like the colours you've captured here and the details in the main bodies of the galaxies. Good work:)

[Stevec35]

Not bad at all Greg. I don't know if you ever use differential high pass filtering but you could probably squeeze some more detail out if you did.

Cheers

Steve

[gregbradley]

Thanks JJ. It turned out better than I expected. It is a bit of a tough target.



Yes I sure do. I think I'll get a tripod for the PME and take it down there for like a week or so when there's a good forecast.



Thanks Peter. It turned out more colourful than I expected. It looks a bit like 2 ears!



Thanks Dave.



I like images that highlight these tidal streams. A very interesting
aspect of galaxy images.



The tidal streams make it.



That's great Chris. I am glad you like it.



Cheer Paul.



Thanks a million Ross.



Equipment has advanced a lot.



Thanks Marc. It is a tough target so I wasn't sure if it was going to be one reserved for the dark site.



Thanks for the interesting data on this target.



Thanks very much for that.



Thanks Steve. I do use some high pass filtering. I am not sure of the term differential high pass filtering. What is that? Is that multiple high pass filtering at different pixel values?

High pass filtering pushes up detail to a point. Then all it does is accentuate noise. So I feel I pushed this sharpening and high pass-wise as much as I could without the result being too noisy. But perhaps there is a technique that can extract a bit more without the noise?

Greg.

[Lester]

Wonderful image Greg, thanks for the view.

[multiweb]

+1 . This rig needs altitude and dark skies, then it will really sing. Moving to Thredbo? ;)

[Bassnut]

Yes, thats nice Greg, but having done this myself with a pokey 10", geez, it seems a bit soft with fatish stars.

I cant put my finger on it exactly, perhaps the exposure time, I did 10hrs lum, that might be the diff.

Did you process much in PS?, was focus OK?.

[marc4darkskies]

I think it's a nice shot Greg, but I agree with Fred. Considering it's with a 17" it's looking a bit soft. Have you compared it to other images done with gear of a similar aperture?

Cheers, Marcus

[gregbradley]

Not sure Thredbo would be any good as its pretty windy there.
But yeah a trip to my dark site could be an interesting exercise.


Thanks Lester.



It was taken over 2 nights. I am not exactly sure what the seeing is like but generally speaking the seeing at my home is not as good as the seeing at my dark site which tends to be quite good.

Red subs seemed a bit bloated but luminance seems OK.
Extra time always goes down well.

I am happy with it as is. I am sure a better version could be made as with any image.

A trip to my dark site with a tripod for the PME would be interesting.

I'll also have to check collimation as I haven't collimated it since I got it as CCD inspector said it was close. I should really tweak it though.




Most images of this object aren't particularly sharp or lack colour.
It could always be improved. I noticed the red subs were fat so perhaps temperatures shifted and a refocus was needed. Still I think it turned out well. As I said above luminance is pretty sharp.

[strongmanmike]

Am I imagining it or were your early shots with the 17" a bit sharper? :question: I am imagining it is a seeing issue...hell I know about that :rolleyes:

Never the less still a cool easy grab of a cool looking object.

Mike

[gregbradley]

Perhaps its time to check collimation.

Greg.