Southern Virgo Deep Field - enhanced colour version added

[strongmanmike]

Here is a 1.8deg X 1.8deg field encompassing galaxies NGC 5068 and 5084 (along with many others) in Southern Virgo

This is my longest and thus deepest exposure using the AG12 and totalled 9 hrs all up. Under the dark skies of rural ACT this has allowed me to go very deep.

In the full frame colour version I have tried to keep the masses of galactic cirrus (http://www.pbase.com/strongmanmike2002/image/149669509/original) balanced and appropriately bright (well, dim..) compared to the much brighter galaxies to hopefully display a believable field

Here is the FULL FRAME (http://www.pbase.com/strongmanmike2002/image/149669214/original)

And as usual I have produced some variations to showcase what is actually there, as well as some close up crops to see the details - you can see them all HERE (http://www.pbase.com/strongmanmike2002/galaxy_pair_in_southern_virgo) (click on Original size at the very bottom of an image page)

[h0ughy]

:eyepop: :eyepop: :bowdown::bowdown:

mike mike mike mike mike!!!!! out with the dyson!!

all those galaxies:thumbsup::thumbsup: unreal:thumbsup:

[alan meehan]

Lovely Mike
Southern Virgo so much detail looks like you have enjoyed the nine hrs worth
AL

[Larryp]

Wow! That IS nice, Mike!

[whzzz28]

Brilliant.

The dust channels really make the image!

:party2:

[David Fitz-Henr]

Super image Mike! Nice and deep and heaps of galaxies - well done! :thumbsup:

[ChrisM]

Mike, that is a great result and well worth your effort. I agree that the wispy clouds add something to the image.

Have you worked out how deep you've gone?
Chris

[madbadgalaxyman]

Mike!!

An excellent capture of the unique NGC 5084, which doesn't really look like any spiral galaxy that we are used to seeing!!

Remarkable that such a strange galaxy has had very little attention from professional astronomers.

There is evidence here of multiple planar structures and multiple disks within a single galaxy, at different spatial scales (disks of various sizes) and at several different position angles!

cheers,
Robert

I would be very curious to know what N5084 looks like when your image is displayed at maximum contrast.

[tilbrook@rbe.ne]

Hmmm, wouldn't want to lend me your scope :D;).

Just love these deep galaxy fields Mike!

Do you see the galactic sirrus in the individual subs, or just in the final image?

Cheers,

Justin.

[multiweb]

Great view. So many different structures and colors in the faint fuzzies. Worth a full size print for the poolroom I reckon. :thumbsup:

[marc4darkskies]

Oh yes! .... Oooohhhh yeeeessss!! Gorgeous Mike! :thumbsup::thumbsup:

Make it pop a bit more though mate - move the black point up - histogram is too gappy at the black end.

Cheers, Marcus

[gregbradley]

Superb Mike. Congrats on a super image.

Greg.:eyepop:

[RB]

Stunning Mike !

[Paul Haese]

A cool field of view Mike. Very smooth image with a nice view to the varying distances of galaxies here. The two close ones and then galaxies of further and further distances. The two galaxies in the foreground are so different looking this provides an interesting look to the image. I like the galactic cirrus that is visible looking like very faint smoke in the view I have. Only thing I would change is the slight magenta cast to the background. However this is still a very nice image, but not as nice as this one (http://www.pbase.com/strongmanmike2002/image/146908568)you did not long ago. That is in my opinion the best galaxy field you have produced to date. Certainly closely followed by this one. :)

[jjjnettie]

Wheeee!! So many galaxies, so much dust. :)

[cybereye]

Bravo, Bravo and one more Bravo!!! That image deserves a standing ovation so I'm standing while I type this!! :thumbsup:

Cheers,
Mario

[RobF]

Yep, wild applause here. Love it.

:clap: :cheers:

[strongmanmike]

Ah Houghy, luv ya mate, you my wittle brother :love2: :P



Yes finally getting good conditions was fabulous, I knew from the subs as they came down (no high clouds, free of wind and in half decent seeing) it was going to work :thumbsup:



Cheers Lazza



They were one of the main things I was after, I knew they were there thanks to Malins image (http://www.pbase.com/strongmanmike2002/image/149626499/original)



Cheers Dave, since I've had the scope I have waited patiently to have her in good conditions at a dark location...it's like a whole new girlfriend :P



Cheers Chris, nup, no idea but as far as the extended faint features go I recon preeeetty deep :D



Cheers Robert and interesting feedback too thanks. There is a high contrast negative version HERE (http://www.pbase.com/strongmanmike2002/image/149669509/original) that I did to showcase the extent of the galactic cirrus and you can see NGC 5084 in that. I also tried stretching and seriously increasing the contrast to look for any faint tidal streams but I couldn't find anything definite :question:.



Thanks Justin, suuuure you can have my scope..:question:...if you can beat me in a good old fashioned arm wrestle :D. Yes, the cirrus is indeed visible in a single 5min sub but it is very hard to make out as it blends in with the the noise - a good example of why taking many subs works wonders :thumbsup:



I agree, might try that...need to get a pool table first though :question:



Cheers Marcus and you may be right (again :rolleyes: :lol:) but I didn't want to remove anything from those reeeeally faint areas of Cirrus (the stuff is everywhere, even in the apparently dark patches!) which happens when the contrast is lifted, so I left the levels where they are...perhaps I am just being anal :question: :rolleyes:



Thanks Greg, It is fields such as this that I was always seeing in my mind over the nearly 5 (sometimes painful :rolleyes:) years I tried to get my hands on such a (working! :mad2:) OTA :)



Cheers Zorba :D



Great appraisal Paul cheers and I agree about the layers of galaxies (see response to Greg above :)) :thumbsup:



You can get out the Hoover JJJ..? :D



Well, Grazie Mille Mario :)

[strongmanmike]

:cool::rockband::family:

Cheers Robbo :)

[RB]

:lol:

We missed you at IISAC mate, and I had plenty of Guinness on ice for yah.

:sadeyes:

[alpal]

That's gotta be an IOTW.

It's a superb image.

:eyepop:

[Phil Hart]

I can see why you're pleased with this image Mike.. I sure would be. Lovely field.. holds up real nice when viewed big on screen.

If you're looking for how to squeeze the most out of it, I agree with Marcus and Paul. For sure you want to show the cirrus and you've done very well with that.. but it should be possible to have some very nearly black pixels in the image somewhere. I would be using some kind of curves adjustment to try and stretch out that dark end towards the black point a bit more.. should give even better visibilty of the cirrus (but will kill some of it for those with poor monitors).

And there is some kind of purple/magenta cast to it.. I think it's more due to the star colours than the background. Your other image that Paul linked to has a nice mix of yellow and blue stars. This image seems to have yellow and many purple stars (some blue but not so many). Don't know how you managed it but if you could fix it then it really would be a cracker! :thumbsup:

Phil

[lazjen]

This is a great image. Many galaxies there. Awesome.

[strongmanmike]

Any cigars? ;)



Thanks a lot :)



Cheers for the critique Phil, Galactic Cirrus is often processed so it looks like it has been processed separately (today's APOD is a good example of this - for me the relative brightness differentials in this image are all wrong). I wanted it to look like a natural part of the image with a realistic brightness differential, so this aspect I was happy with. As for your other comments, thanks, I'll have a think :thumbsup:

Mike



Glad you liked it, plenty of stars too :)

[Phil Hart]

I agree! I think you 'respected the light' much better than that APOD!

[ourkind]

What a beauty Mike! Nice to see them winds giving you a break :thumbsup:

[lacad01]

Amazing how many galaxies framed, excellent stuff. :thumbsup:

[RB]

No, reducing my carbon footprint mate.

:lol: :thumbsup:

[LewisM]

Supercalifragilisticexpialidocious! !! :rofl: :P

[strongmanmike]

Sogladyoulikedit :D

Mike

[strongmanmike]

Cheers Guys :thumbsup:

...wind...ahhhhhhh :windy:

Mike

[madbadgalaxyman]

Hi Mike,

Thanks for pointing out your high-contrast version of your image.

As mentioned in my previous post, NGC 5084 has a very unusual appearance. This galaxy is a really excellent subject for your ultra-deep imaging/exploration project, as the peculiar-looking outer disk is of extremely low surface brightness. In fact, if this galaxy were seen face-on, I have a feeling that the faint outer structures would be undetectable.

There exist a few individual galaxies, within the population of bright galaxies to apparent Blue magnitude 13.5, where there is at least the impression of two (or more) different planar structures existing instead of a single "fundamental plane" in which the spiral structure sits. But the interpretation of more than one disk seems quite secure for NGC 5084.
(compare, for instance, the "tilted or bent" Equatorial Dust Lanes seen in NGC 5078 and NGC 3628)

It is pretty easy, in theory, and also in practice (in the real universe), for gravitational interactions with another galaxy to warp or bend the Planar Disk Structure of a Spiral galaxy or S0 galaxy away from its principal plane;
in fact, in some cases, this sort of interaction can virtually "make spaghetti" out of the disk [this is, I think, what has happened in NGC 4438, which was probably originally an ordinary-looking edge-on S0 galaxy....in fact its bulge component (its spheroid) is still normal, despite the strong distortion of its outer regions. ]

However, in NGC 5084, we seem to be looking at (at least) two moderately-well-behaved disk structures, seen edge on, at two or more position angles.

If I had to gamble on what is going on here, I would put my money on the idea that the outer extremely-faint disk, which is not very settled in its appearance, is:
- still being formed (that is, it is coalescing under the influence of gravity)
OR
- being re-formed after being disrupted.

There are a small number of galaxies in which the outermost disk has been nearly-proven be currently in the process of ongoing formation (this idea applies, probably, to M31 and our own Galaxy!). And this is a phenomenon that has been expected for a long time on theoretical grounds.

I might mention the NGC 5084 case to the brilliant Dr Kenneth C. Freeman of ANU, as he is an authority on the behavior of the planar components within spiral and S0 galaxies.

Best Regards,
Robert

"Just for fun and profit", here is the g+r+i band composite image from SDSS:

137167

It would be interesting if the outer faint disk turns out to be "in the process of being formed" rather than a result of gravitational interaction with other galaxies!

[strongmanmike]

Thanks for posting all that Rob and the SDSS image is very revealing.

I have composed a side by side comparison HERE (http://www.pbase.com/strongmanmike2002/image/149719092/original) of that image with my data and it would seem I have gone almost as deep as there are very few stars or galaxies in the SDSS data that can not be picked out in my data. This is surprising as if I am not mistaken that SDSS composite incorporates IR data..? I assume that is what the "i" stands for in g r i..?

Mike

[madbadgalaxyman]

Very good, Mike, considering that SDSS used a 100 inch telescope!

The SDSS i filter is essentially Deep Red to Very-near-infrared, with a central wavelength of 7480 Angstroms.
(u is blue to very-near ultraviolet)(g is 4686 Angstrom)(r is 6166 Angstrom)

They use the bandpasses called u, g, r, i, and z, as per this filter transmission curve:

137257

The z band is their longest-wavelength filter, which is essentially an infrared filter of the sort that can be used with a standard CCD.

These ugriz filters have become as much of a standard as the Johnson-Cousins UBVRI filters, for calibrating images and for photometry. I do not know the ugriz system well, so it is giving me plenty of headaches!

Best regards,
Robert

It seems to me that I ought to be looking into this galaxy a bit more, but in typical fashion, this work could end up joining several other uncompleted projects.
(currently I am sweating on the evolutionary histories of star clusters, and their chemical enrichment with heavier elements by the ejecta of previous generations of stars.....this is just another one of the infinity of things you have to know very well, if your goal is to understand galaxies!)

P.S. The colours displayed in SDSS g+r+i composites are absolute rubbish! However, one very good thing about it is that the blue channel is very sensitive to recent star formation and OB stars.

[FlashDrive]

:thumbsup: What can I say....makes our little spot in the Universe insignificant ...!!
Gosh...I feel so small ......

Flash .....

[strongmanmike]

You bet Col cheers

Love galaxy fields, love'em :thumbsup:

Mike

[strongmanmike]

Cool huh? ;)

Mike

[Ross G]

A beautiful photo Mike.

Colours, detail, sharpness.......amazing!

Great composition too.


Ross.

[strongmanmike]

You're too kind Ross :)

Mike

[iceman]

Stunning work Mike, artwork at its finest.

[strongmanmike]

Cheers Mike...After looking at your remarkable shot from Lostock, I am going to try a reeeeeeally long exposure with my car in the foreground really polished up and see if I can get a reflection of the Milky Way Cirrus in the paintwork and windscreen :P :lol:

Mike

[iceman]

5-10 hours of polishing followed by 5-10 hours of exposure should do it..
:lol:

[strongmanmike]

Done...I've got the hired help on to it already....

[naskies]

Wow :eyepop: Deep field indeed!!

[strongmanmike]

Yes pretty deep I think but once I have her in the Sirius dome (dug the site cut yesterday, pier hole tomorrow!!) I have some long exposures planned ;)
Let's see how deep she can go with 20hrs Lum :D

Mike

[strongmanmike]

Here is a full frame colour version with enhanced Galactic Cirrus

Little bit noisier I guess but sheesh...this stuff is FAINT!

In the end a compromise, still looks cool having galaxies sitting in ultra faint Milky Way dust :)

Ultra Deep Field in Southern Virgo (http://www.pbase.com/strongmanmike2002/image/149901975/original)

Both versions can be seen HERE (http://www.pbase.com/strongmanmike2002/galaxy_pair_in_southern_virgo)

Thanks for putting up with me :P

Mike

[gregbradley]

Great work Mike. That 12inch is working beautifully.

Greg.

[strongmanmike]

Cheers Greg, yes quite happy with the AG12, it is delivering essentially what I was after, will be good to have her under the dome though, should be more productive then and open up more imaging possibilities. Still have to attach the new SX camera and OAG yet too.

Mike

[LucasB]

Great Stuff Mike. Love the depth!:thumbsup:
Lucas

[strongmanmike]

Cheers Lucas, yes this scope and camera lends itself well to going deep :)

Mike