ABELLS805 Galaxy Cluster in Pavo

[strongmanmike]

At 200 Million Ltys distance this is rather old light collected here.

This was another test of the resolving power of the AG12 with its modest FL of 1120mm when coupled with the beaut little SX camera and OAG

The largest and brightest galaxy in the group is the big elliptical IC 4765 at 3.2' X 1.8' and Mag 12.4, all other galaxies are under 2' in size and most are less than 1' (luckily the seeing cooperated) and very faint Galactic Cirrus dust covers the whole field too

ABELL 805 (http://www.pbase.com/strongmanmike2002/image/152595656/original) (central area)

Galaxy Chain in ABELL805 (http://www.pbase.com/strongmanmike2002/image/152595686/original)

Comparison with 2m Faulks South Telescope (http://www.pbase.com/strongmanmike2002/image/152595702/original)

Field of Dust (http://www.pbase.com/strongmanmike2002/image/152595816/original)

Hope you find it something a bit different and an interesting area :)

Oh and just for Paulie H here is the full frame (http://www.pbase.com/strongmanmike2002/image/152595655/original)

Mike

[multiweb]

Looks really good. Joe Cauchi showed us the same field at the last AIM. Lots of various shapes and colors. :thumbsup:

[RickS]

Really nice, Mike! The scope and camera are working very well together.

[Stevec35]

Nicely done Mike. An interesting group of galaxies well imaged.

Cheers

Steve

[rogerg]

Stunning Mike, absolutely beautiful. I dream of capturing such images.

I might be wrong, but it looks to me like the limiting factor is not the resolution of the optics but the atmospherics. Makes me wonder how much close to the quality of the 2m you could come with tones more data.

[astronobob]

Well done Mike,, stunning scene and great quality imaging.
Id have a go at this just to see if I could pick out the galaxy's from the stars, yep ! Interesting seeing in your Image such distant Galaxy's swarming in one area, very unique field all considered !
Always an amaizing hobby seeing this astro stuff. :thumbsup:

[Larryp]

Looks great, Mike!

[madbadgalaxyman]

Mike,

I am very pleased to finally see a good image of this compact and galaxy-rich cluster. It is one of the least known galaxy clusters within a redshift of 5000 km/s, and there are at best only one or two papers written about it by the professional astronomers......probably on account of its southern position.

Yep, you have cracked a tough one here, given the small angular size of many of the galaxies.

I am glad you are imaging Pavo, as the very many fairly-bright galaxies in this constellation are probably the least known galaxies in the entire sky.

Best Regards,
Robert

[alpal]

Great results Mike - I lost count of the number of galaxies.

[peter_4059]

The full frame is impressive. So many galaxies. Thanks for the view.

[broca]

Excellent work Mike!

[Astroman]

Awesome work, very nice, thanks for sharing.

[Allan_L]

Thanks Mike,
As a humble observer, I appreciate the effort you put in,
and the amazing result.
Thanks for sharing this
A fantastic capture :thumbsup:

[DJT]

Great image Mike, galaxies galore.

[madbadgalaxyman]

Hi there, Mike and friends,

This cluster of galaxies is discussed in detail, in this "Observation Reports" thread by ngcles:

http://www.iceinspace.com.au/forum/showthread.php?t=77826&highlight=4765

Note in particular the interesting morphology of IC 4767; these giant Boxy and Peanut-shaped bulges are quite common in clusters of galaxies but they are rare amongst the nearby galaxies. (won't find too many looking like this in the famous galaxy atlases)

cheers, Robert

[strongmanmike]

Thanks for checking it out guys, glad you like lots of galaxies as much as I do :D

Always enjoy the mountain of info you have on galaxies Robert, thanks :thumbsup: Yes I have imaged a few galaxy clusters now and I too noticed these peanut shaped galaxies, which you don't seem to see outside of a cluster environment...single ring yellow galaxies are common in there too :question:

Mike

[cosmophoton]

A wonderful image Mike, fabulous details and colors.

Cheers,
Luiz

[gregbradley]

Super image Mike. I am liking these H694 /AG12 combo images. Its doing very well in these high mag shots.

Greg.

[strongmanmike]

Cheers Luiz

and Greg, the AG astrographs and I suspect all astrographs of this basic design, apart from heavy stiffening around the tube-focuser junction, definitely need OAG, particularly when using the big ProLine like cameras. I had differential flexure when I was using the ProLine meaning even exposures of just a few minutes showed diff flex. With the SX OAG now it is no longer a problem and I am now using exposures of 10min and could go longer but see no need. I always knew this (and could have improved my piggyback guide scope arrangement too!!!) but I just put up with it. Sometimes it takes a change to really realise just how bad it was :lol:

When I return to the using the Proline on the AG, or any other scope, I will be incorporating OAG in the train for sure.

Oh and remember, this image used no flats and no darks.

Mike

[naskies]

What a great field of little galaxies!

[Paul Haese]

Love the wide field of view of this multitude of Islands in the universe. Colour is nice too. Working on ngc55 at present doing 30 minute subs just to get the faint flurries coming out like this. We'll done.

[strongmanmike]

Cheers Dave an Paul

Paul, yeah I used 10min subs for lum and just 5min for RGB :D one advantage of 12" over 4" and F3.8 helps too, as does the sensitivity of the little SX camera :)

Mike

[John Hothersall]

Thats a very nice presentation, love the variety of structures and the stunning blue star at the bottom.

John.

[Joshua Bunn]

Love your work Mike, thanks for sharing.

[PRejto]

I love that wide field Mike. Excellent in every way!

Peter

[astroron]

Fabulous pic Mike,plus some great info from Les,Robert and others.:thanx:
On my observing list for tomorrow night,weather permitting.:)
Cheers:thumbsup:

[Ross G]

A great photo Mike.

I love the full frame shot.

Well composed with beautiful colours.


Ross.

[strongmanmike]

Thanks for the comments guys, glad you enjoyed the view :thumbsup:

Have fun observing these little blighters Ron

Mike

[Shiraz]

another exceptional image Mike - your small pixel setup is really letting you produce the goods with galaxies.

[strongmanmike]

Hey thanks Ray

Yes I must say the H694-SX Off Axis Guider combo is the secret here plus the small pixels :thumbsup: I should have looked for a way to incorporate an OAG when using the big ProLine rather than stubbornly persevering with a heavy poorly mounted piggyback scope :doh: Trouble is having the Atlas focuser + OAG unit + CFW + ProLine makes for a very heavy setup mounted radially on a Newt :question: even with the heavy bracing the AG12 possesses.

I hope to have a longer FL catadioptric at some stage in the future and I think such an image train would be more easily stabilised on this.

Mike

[tilbrook@rbe.ne]

Marvelous image Mike!:thumbsup:
Reminds me of the Hubble southern deep field.
Always amazes me the resolution you get from your setup.

Must be tricky not to process out that fine detail, many years of experience helps.

Cheers,

Justin.

[SpaceNoob]

Far out!! literally! :thumbsup:

Amazing image Mike, love the tiny spirals in the wide field.

[jase]

A clean and tidy image Mike. Great stuff! You can crop to your heart's content, but the full frame does it for me as the image needs the perspective. Most enjoyable.

[Octane]

Magnificent image, Mike.

Those galaxies... goodness me.

H

[strongmanmike]

Thanks Justin, yes the new image train is doing what was intended :thumbsup: One of the reasons I am careful with noise reduction, don't wanna smooth out those 300 Million Ltyr distant galaxies :scared:



Cheers Chris, gotta love little spiral galaxies.... seen as they were when dinosaurs first appeared on earth :question: :eyepop:



I always tidy my room, thanks daddy Jase :lol:

I like the cropped version because it seems to make the small galaxies look distant rather than just smaller :)



Thanks Humayun, as I said to Jase above I guess that's why I like the cropped version best, the tiny galaxies look, at least to me, like they are hovering way behind the larger closer ones and not simply smaller :)

[h0ughy]

strange i thought i commented on this wonderful image? must be suffering photon dementia

[strongmanmike]

Ah nooo you didn't...sooo..? :whistle: welll...?? :shrug: come'on then...comment! waiting... :rolleyes:

:P

[h0ughy]

itsa veri nica image Michele

[strongmanmike]

Grazie Signore Hougha :love:

Michele

[acropolite]

:bowdown: Fantastic Mike.

Makes you realise how insignificant our little bit of rock is within the big picture.

[strongmanmike]

Cheers Phil and I completely agree. Under darker steadier skies now with this beaut scope I have become a bit of a galaxyphile :evil2:

Mike

[Leonardo70]

Wonderful Mike .. i love this galaxies ...

All the best,
Leo

[cybereye]

Mike,

I go away for two weeks and this is what you do. Fantastic!

Cheers,
Mario

[marco]

Very nice Mike! I almost missed this beauty, love everything of this image, color, contrast, subject.. well done :thumbsup:

Marco

[strongmanmike]

Aaaah my Italian mens club :love: :thumbsup:

Cheers migliori amici :D

Michele

[SkyViking]

Aah yes, galaxy clusters! Wonderful image, there is so much to look at. Colours are great too, very well balanced. It's certainly an inspiring image Mike, very well done!

My imaging is somewhat on hold right now since it's been rather cloudy here at night lately - and Mr. Royce has notified me he finished the 12.5" mirror so I expect to receive it soon, just in time for the clear summer nights. Then I'll put the new OTA together and go galaxy hunting, wohoo! :)

[strongmanmike]

Hi Rolo, thanks mate...dunno how you maintain the patience to go for long exposures liiike saaaay...120hrs?..I start of thinking, right! going to go looong on this one...then the weather gets cranky, clouds get in the road etc,...and after a few annoying nights...meah.. I get bored :doh:ee :lol:

Great news on the 12.5" :thumbsup:...an extra 0.5" over me now..?.. humf! :mad2: :lol:

Mike

[SkyViking]

Hehe, yeah for sure you'll be left in the dust Mike, that 0.5" will give certainly me the edge.:P:lol: You'll probably notice the stars fading the very moment I point my mighty new photon grabber towards the skies. :lol: :rofl:

Nah, but I'm certainly hooked on mega data, and I'll definitely try a similar project once I get the new scope ready. It's exciting to watch the data accumulate night after night, it was really quite addictive. :thumbsup:

[madbadgalaxyman]

Mike,

I have been having another look at your image of the IC 4765 galaxy cluster. Small galaxies here, but they are nicely seen in your image.

This is, for me, one of your very most interesting images, as this cluster is very very rarely imaged by anybody, and there is hardly anything known about it, even by the "pros".
(in fact, the galaxies in Pavo are the least known in the sky, judging from the tiny number of scientific papers written about them)

The halo of the giant dominant elliptical galaxy is not symmetrical, if I am correct in my interpretation of your image....
it seems to stretch outwards a lot further along the upper side of the major axis of this galaxy.

I don't know whether the extremely faint luminous background which I seem to see extending away from this galaxy is the intracluster (inter-galaxy) light or whether it more properly belongs to the halo of this galaxy.

There are a number of cases in the literature where the exceedingly faint luminous halo of a big elliptical in the middle of a galaxy cluster essentially merges, at some radius, with the intracluster light;
so the distinction may be somewhat academic.
( a good example of this is M86.....if you measure the total magnitude of M86 to successively greater radii, the total brightness of this galaxy just keeps on increasing.....there is no radius at which the magnitude stops getting brighter!!!)

[ The intracluster light in galaxy clusters is not unusual in terms of its composition, in that its light just comes from plain ordinary stars....but the stars belong to the cluster of galaxies rather than to any individual galaxy]

cheers,
Robert

I don't suppose that these giant Elliptical galaxies are the most exciting looking galaxies in the sky, but they are often the most luminous galaxies in the universe; some examples get two magnitudes more luminous than even the most luminous spiral galaxy.

They do have sort of subtle "layered" structure, sort of "onion-like", as has been very evident to all of us who have followed your NGC 5128 imaging project, in that the shape and position angle of one of these galaxies can change two or more times, depending upon the radius to which the galaxy image is displayed.

One of my favourite examples is NGC 6876, which has a centralmost or nuclear feature, surrounded by an oval distribution light, surrounded by a spherical distribution of light, surrounded by a probably-off- centre very-extended distribution of light. Some hint of this structure in these isophotes:
152708

[trent_julie]

Mike,
The full frame is tops! An inspiration as per usual.

Trent

[strongmanmike]

Yes I was intrigued by the stars/dust/halo structure component of this cluster too and how much is Milky Way Cirrus and how much is actually the big elliptical which appears to stretch right across the cluster (http://www.pbase.com/strongmanmike2002/image/152595816/original)..?

Mike



Hey thanks Trent, glad you liked it :)

[marco]

Excellent image mate! I love these galaxy clusters and you gave this one the full glory it deserves :thumbsup::thumbsup:

Also colors are splendid, I tried to find out some defects but could not ;)

Clear skies
Marco

[madbadgalaxyman]

Thanks for displaying the high-contrast version of your image. The vast "halo" of this galaxy looks quite obvious here.

I think that the ultra-faint luminous extensions of the big elliptical are not cirrus. That's my opinion, anyway.

They don't look like cirrus to me, in fact they look more like a component of IC 4765 itself.

The surface brightness, and the falloff of light with increasing galactocentric radius, and the distribution, of this light seems to be distinct from that of the cirrus that is in this field.

It is pretty cool to see this galaxy extending so far across the cluster!

This appearance is not necessarily unusual for those galaxies that are dominant in their clusters, but it is generally very hard to actually get decent images of this vanishingly faint light stretching between the galaxies of a cluster.....
so all credit to you, Mike.

The velocities of the stars that are responsible for the ultra-faint diffuse light can be used to separate out those stars belonging to the galaxy and those stars belonging to the cluster; there is no other way of doing this.
It is normal to try to get spectra of planetary nebulae in the diffuse ultra-faint light, in order to figure out the velocities of stars in our line-of-sight.
(this requires a "beeeeg" telescope)

Here's one of my all-time favourite images, showing the ultra-faint inter-galaxy light in the Virgo Cluster.
I think I may have shown this one to you before, but perhaps some of the other IIS members would also benefit from thinking about this very weird image:

152761

[Gem]

Wow - that's a lot of galaxies! Love the full frame! :)

[strongmanmike]

Thanks for checking it out guys, did this one a while ago now :)

Mike

[strongmanmike]

Cheers Rob, I do some strange things to my data and I know some roll their eyes at it :lol:...but it's just so much fun to do in this modern age of sensitive digital imaging, lots of interesting things can be seen if one streeeeetches their data :P

Mike

[madbadgalaxyman]

Yeah,

I think that your approach of having a closer look at what new information you can get out of your data, shows that there is the potential for new discoveries in images of galaxies.

It is not easy to "decide what is real and what is not" on an image, at extremely low contrast and surface brightness. ( I am going to have to come to grips with some of the mathematical image analysis tools developed by professional astronomers if I am to prove the existence of some of the unusual things that I sometimes notice in amateur galaxy images.)

There is nothing easy about making discoveries in astronomy.....indeed, most professional astronomers don't exactly make lots of major discoveries in their lifetimes.
So the observational approach of having a really close look at galaxy images is as good as any for trying to find new and weird things in the universe......
"After all, it's a bloody big universe , and there are undoubtedly stranger things out there than you will find in your breakfast cereal box"


Best regards,
Robert

Have you contemplated Marco's deep image of the M49 field....what a busy field, and so much strangeness and interest in it. The great variety of objects makes it one of my current favourite fields.
(tidal distortions ; spirals ; S0s ; giant ellipticals ; galaxies with smooth arms and damped star formation; it has got the lot!)

[E_ri_k]

Love that full frame Mike :)

[TimberLand]

Mike,

Just copying what everyone else has said, Great Image. :thumbsup::thumbsup:

I too am a fan of galaxy clusters and you have done this one amazing justice. Good to see the camera and scope fit well together, looks like a great combo with the OAG.

The comparison is good to show how good amateur gear has got these days, keep the inspiration coming.

Justin.

[strongmanmike]

Faint things are my speciality...even if I am the only one who can see them :lol: :P

Yes marcos M49 field is rather busy, looks like a drop of dirty pond water under a microscope...strange weird looking galaxies everywhere :thumbsup:




Thanks Erik



Thanks Justin, not everyone is a fan of my work and display style and hey, that's cool :) I do like colour and just like to really look at my data and results and try and see things in it that would otherwise go unnoticed and I find this exciting and loads of fun.

Thanks again for your kind words :)

Mike