3000 galaxies and a gravitational arc in Abell2667

[Shiraz]

Hi. Abell2667 was imaged by Rolf a while ago, so decided to have another look.

screen size: http://www.astrobin.com/full/221268/0/
full res, resampled 140%: http://www.astrobin.com/full/221268/0/?real=&mod=

The most amazing characteristic of this region is how many galaxies there are - maybe 3000 are visible as faint smudges (down to about Bmag25). Most are found in a sweeping arc from the top left to bottom right in the image, but they are also spread across the rest of the field at lower densities. An intriguing and highly red-shifted group is seen at the left of http://www.astrobin.com/full/221267/0/ which is from the top left of the main image - these are a lonng way away.

There is a high mass concentration down and to the left of centre in the main image - this is the Abell2667 region imaged in one of the Hubble Frontier Fields. The image is lightened a bit and shown alongside Hubble data for easy interpretation: http://www.astrobin.com/full/221266/0/. The main galaxies are redshifted by z=0.23, so the light has taken about 2.8 billion years to get here - and the UV light (now blue) is reduced by some stellar absorption bands, so most galaxies look yellow/orange. The big blue galaxy is radiating significant UV (now blue). It is being torn apart by gravity and pressure effects as it falls through the intra-cluster medium. Some of the galaxy scraps can be seen as a wake. The other main interest in the region is the huge gravitational arc, which is a magnified triple image of a far off galaxy situated well behind the main cluster. The gravity in the cluster is sufficient to form a lens (the equivalent of a refractor much bigger than the milky way) and this magnifies and condenses the background light. The arc has a red shift of z=1.03, which means that these ancient photons have been travelling for about 8 billion years. When they started out, the solar system did not exist and the universe has changed so much since that the UVA, UVB and UVC light from the arc galaxy is now (roughly) RGB - the colour actually looks like it does not quite belong in this universe come to think of it...

had great fun imaging and trying to understand more about this region - thanks for looking. regards ray

P.S. don't bother with the JPEG below - it doesn't show the whole region.

[FlashDrive]

Just Amazing .... makes our solar neighbor hood looks so insignificant.
A lot of stuff out there.....
Thanks for the pic and info

Col.....

[Placidus]

A magnificent image, Ray. The gravitationally lensed arc is spine-tingling. It's going to take me quite a while to fully absorb this one, but wanted to say something straight away. Thanks for the careful explanation.

Very best,
Mike

[RobF]

Mind blowing really.
Thanks Ray. Awesome work. Mesmerizing field....

[DJT]

Love it. Swanning around the galaxy clusters on the iPad. nicely handled, interesting info. Thanks for sharing, Ray

:thumbsup:

[Rod771]

Amazing,Ray! Totally mind blowing. Appreciate the info. :thumbsup:

[Peter Ward]

While there are many pretty pictures out there only a handful have the ability to inspire....which you've done in spades here :thumbsup::thumbsup:

[alpal]

Hi Ray,
you're doing very well with that 10" f4 Newt.
This latest picture is very interesting - so many galaxies!
It gives me some encouragement with my Newt.

cheers
Allan

[DJScotty]

Superb image ray. The detail is absolutely mind blowing.

:thumbsup:

[Paul Haese]

There are so many orange smudges. Drake equation Ray?

[strongmanmike]

A very interesting project Ray with a very worthwhile outcome, great work!

Comparing with Hubble data really allows us to interpret what we have captured and shows that there is probably plenty of stuff in many of our images that we just write off as stars but may indeed be much more :)

Great bit of imaging

Mike

[Stevec35]

A very impressive result Ray!

Steve

[Somnium]

that is simply stunning Ray, it is images like this which are the reason why i love astronomy so much. it starts to give you some perspective of the scale of the universe.

[Shiraz]

thanks Col. we are a just a dot on the map really.


thanks Mike. There are quite a few interesting papers on this area - found most using Google scholar.


thanks Rob - appreciated


Thank you David - it is interesting to ponder how much there is out there.


Thanks Rod - just hope I got most of the info right...

thank you Peter. that's very generous.


Hi Allan. thanks - looking forward to your next image with the new scope.


thank you Scott - much appreciated


thanks Paul. The Drake equation can give anything you like, but we have one example of a galaxy with at least one advanced? civilisation at the current time, so taking that single point as the best available data, then each of these 3000 galaxies may have had a roughly similar civilization when this light started out .... or not


that's a good point Mike. In the plane of the Milky way, we obviously see stars, but in out of the way places, galaxies rule if you go reasonably deep - which is staggering.


thanks a lot Steve


Thanks Aidan - yep, I can't get my head around these far off clusters, but it is fun to try to understand how vast the universe really is.

regards Ray

[Joshua Bunn]

Ohh WOW!! That just brought a huge grin to my face and made me laugh... simply breathtaking... Thankyou.

[andyc]

That's pretty special. I'd casually wondered if gravitational-lensed galaxy arcs were possible for amateur imaging, you've shown that beautifully! And the whole image is a treat to explore.

Two quick questions:
There's a broad faint bluish streak on the centre right of the image - any thoughts on what it is (IFN, something else?)

What exposures did you use for imaging?

[Shiraz]

thanks Joshua - glad you enjoyed it.


Thanks Andy. the streak is aligned with the spider diffraction patterns, so it might be diffraction from a bright out-of-field star. It could also be light leakage (camera?) since my imaging environment is fairly bright due to local streetlights. Still to tie down exactly what it is.
Exposure? - will get back to you. there have been a lot of versions of this with different sub selection criteria and I did not keep a tally of how many subs were used in the final version. However, all subs were 5 minutes and the usable data was selected from ~30 hours in total. I think that it is reasonably deep, with galaxies (identified elsewhere) of ~m24 being easily identified and the 3sigma is probably somewhere around m25.

regards Ray

[Joshua Bunn]

Hi Ray, what kind of exposure did you get on this?

[Shiraz]

Hi Josh. Will post when I work out what it eventually was - maybe somewhere around 20+ hours.

edit: was actually 14 hours of luminance and 10 hours of RGB at 5 minute subs.

[SimmoW]

Bloody heck Ray! really amazing image, just how many planets could be in your image? millions and millions.

[marc4darkskies]

Very cool image indeed Ray! :thumbsup::thumbsup:

[Shiraz]

Not sure Simon, but let's say there are 3000 galaxies, each with 100 billion stars and that it averages out that each star has one planet. So the total number of planets in this little bit of sky could be
300,000,000,000,000 or thereabouts (I think). Of course there would be a lot more further out than this lot. Seems it's pretty big out there.


Thanks very much Marcus.

regards Ray

[Octane]

A fusion of science and art.

How small are we?

Simply stunning. Great viewing on my 34" monitor!

H

[SkyViking]

Absolutely gorgeous work Ray, much better resolution and colours than my old puny webcam image! :lol: I've always wanted to do this one again with the proper CCD, so am very glad to see your wonderful result here. Apart from the superb gravitational arc the interesting 'comet' galaxy is also well defined.
The amount of galaxies out there is truly awe inspiring and humbling. Thanks for the view! :thumbsup:

[AlexN]

Fantastic shot mate.

[AG Hybrid]

Super impressive work. Congratulations. On a side note. Holy cow look at the red shift on some of those galaxies on the right! Its pictures like these that make me want to have a good crack at astrophotography. I would even call this image inspiring.

[Shiraz]

thanks very much H. yes, we do seem to be a bit infinitesimal in the overall scheme of things .


It was your image that was the inspiration for even trying to image this area - so thanks for that. I was surprised that the comet galaxy detail included a hint of the wake as well - it certainly is sobering to read the papers describing the environment around it. Also, for interest if you haven't seen it, there is a paper detailing the process of reconstructing an image of the arc galaxy - it is just staggering how much detail Hubble produces. http://arxiv.org/pdf/1410.6594v1.pdf


thanks very much Alex.


Thanks very much Adrian. I think that in future I will have a go at getting some more colour data to see if I can get a rough measure of the red shifts of the far off stuff - should be possible to get some idea.

regards ray

[RickS]

I'm gob smacked, Ray :thumbsup:

[Shiraz]

thanks very much Rick
regards Ray

[E_ri_k]

Great comparison Ray. It's amazing how much shows up considering how far away it is, mind blowing really.

Erik

[Fabiomax]

Wonderful!
You did a great job. Until recently, these were the only immaggini professionals. With these images came further confirmation of the theory of relativity.
Congratulations!

Fabiomax

[Shiraz]

thanks Erik. I agree, it is amazing how much we can see - at about halfway across the visible universe! But there is no doubt that Hubble is orders of magnitude better than anything we can do.


Thank you very much Fabio. It is really exciting to be able to catch a glimpse of some of the things that are at the cutting edge of current optical astronomy.

regards Ray

[alistairsam]

wow just saw this one Ray. amazing stuff.
Love your work. truly inspiring.
incredible what you do with that teensy chip :-)
how dark are the skies where this was imaged?

Cheers
Alistair

[multiweb]

Amazing stuff Ray. Pushing the envelope. :thumbsup: